Amoxicillin Tinnitus & Hearing Loss: Ototoxic Drug of Concern?

Amoxicillin was discovered in 1958 and used medically in 1972 – and remains among the most commonly prescribed antibiotics due to its low cost and safety profile.

It is a moderate-spectrum, bacteriolytic, beta-lactam antibiotic of the aminopenicillin family – prescribed to treat susceptible Gram-positive and Gram-negative bacteria causing: middle ear infection; strep throat; pneumonia; skin infections; and UTIs.

That said, some individuals wonder whether amoxicillin has potential to cause ototoxicity, hearing loss, and tinnitus (ringing in the ears) – so I decided to do some digging in the literature and across the internet.

Amoxicillin & Hearing Loss (Research)

There’s a significant lack of research that’s investigated links between amoxicillin administration and hearing loss, ototoxicity, and tinnitus.

Reasons for this lack of research may be due to:

Age & usage rate of amoxicillin: It’s been on the market since 1972 and is one of the most commonly utilized antibiotics. If it caused hearing loss/tinnitus – it’s likely that this would be regularly reported by patients/practitioners AND documented in scientific studies/clinical trials.

Side effect data: Clinical trial data and adverse reaction reports from patients/clinicians haven’t documented hearing loss or tinnitus as common (or even rare) side effects of amoxicillin administration.

Rarity of this reaction: Perhaps hearing loss and/or tinnitus are extremely uncommon reactions to amoxicillin – and only occur in less than 0.1% or 0.01% of users such that it’s not discussed as a possibility.

Amoxicillin & Risk of Hearing Loss: Analysis of Reported Cases Submitted to the WHO Global Database (R)

This is the only large-scale study that attempts to analyze whether amoxicillin is likely to cause hearing loss or deafness.

• Authors: Russom et al. (2020)
• Aim: Determine whether there’s a causal link between amoxicillin use and deafness.
• Methods: Data mining was carried out in the WHO global database of individual case safety reports and specific criteria (VigiBase & Austin Bradford-Hill) were employed to assess causality.

What were the findings?

A total of 94 cases of hearing disorders related to amoxicillin were documented.

• 49 of 94 cases (52.1%): Reported as “deafness.”
• 18 of 94 cases (19.14%): Amoxicillin the ONLY suspected cause of deafness.
• 13 of 94 cases (13.83%): Amoxicillin was the ONLY medication administered.
• 31 of 94 cases (32.98%): Amoxicillin was “co-suspected” as a cause due to administration with other drugs.

Median time to deafness onset after initiation of amoxicillin treatment was ~3 days.

Outcomes of these cases were classified as:

• Recovered (14)
• Recovering (2)
• Not recovered (16)
• Unknown (17)

In 5 cases, “deafness” resolved following withdrawal of amoxicillin.

What did the authors conclude?

“There appears a causal association between amoxicillin and hearing loss that requires further substantiation with better epidemiologic studies.”

“Even old drugs that have been on the market for decades can sometimes pose new potential risks.”

I agree with this sentiment – but 99.99% of patients will not have this reaction.

Heathcare providers should be aware of this potential risk and encourage patients to seek immediate medical care if they notice any hearing changes or tinnitus while taking amoxicillin.

(This should be advised for every single medication – regardless of type. Encourage patients to seek immediate medical care if they notice any significant changes in hearing or vision during treatment.)

Additional information from this analysis…

From 1977 to 2020 a total of 94 cases of “hearing disorders” related to amoxicillin were documented in the WHO global database of individual case safety reports (ICSRs) – encompassing 17 countries. (Mainly USA: 13; Australia: 10; and UK: 7).

Reported terms in documentation were: “deafness” (42 cases); “bilateral deafness” (3 cases); “transitory deafness” (2 cases); “conductive deafness” (1 case); and “unilateral deafness” (1 case).

Sex was reported in all but 3 cases – and 61.2% were females.

Age as reported in 36 deafness cases – of which 14 (39%) were below age 50, but the median age was ~55.

In the 31 of 94 cases (32.98%) in which amoxicillin was “co-suspected” as a cause of deafness – the most commonly reported co-administered drugs included: gentamycin; metronidazole; and nitrofurantoin.

Gentamycin is highly ototoxic as a standalone agent and commonly causes hearing loss.

Azithromycin, clarithromycin, and erythromycin (i.e. macrolides) are occasionally ototoxic and were co-administered with amoxicillin in 3 cases each (9 total cases).

(Macrolide antibiotics can sometimes cause hearing loss as standalone agents. Read: “Azithromycin & Hearing Loss”).

There is zero evidence from animal studies that amoxicillin is likely to cause deafness, however, the drug “ceftazidime” – a related medication (broad-spectrum, Beta-lactam antibiotic) causes reversible middle ear inflammation with minor ototoxicity in chinchilla.

Important: Confounding variables to consider…

Ages of patients

The median age of patients who experienced hearing loss on amoxicillin was 55.

• It was mentioned that the natural process of aging might be a contributory factor to hearing changes on amoxicillin (some sort of synergistic reaction between age-related susceptibility and the physiologic effects of amoxicillin).
• That said, 14 cases (39%) of deafness on amoxicillin involved patients below 50 and age was NOT reported in every case – so age probably isn’t the only possible explanation.

Co-administered ototoxic drugs

The highly ototoxic gentamycin – and occasionally ototoxic macrolides (azithromycin, clarithromycin, erythromycin) were co-administered in over 10 cases of “deafness” on amoxicillin.

Authors acknowledge that amoxicillin might’ve played zero role in hearing changes in these cases – but it’s impossible to fully rule out.

Medical conditions

Perhaps the most likely cause of hearing changes/deafness on amoxicillin had to do with the type of infections being treated.

Several cases involved amoxicillin for the treatment of upper respiratory infections & ear infections.

• Bacteria responsible for URIs & ear infections may directly damage the inner ears before treatment (to some extent) and/or trigger an immune reaction with inflammatory cytokine/chemokine production (which can also cause damage).
• During treatment the amoxicillin kills bacteria (via a bactericidal effect) and the bacteria may secrete endotoxins/endotoxin-like compounds – which can activate the immune system and further increase inflammation (which could cause hearing damage).

Allergy & hypersensitivity reactions

It’s reasonable to suspect that a subset of patients treated with amoxicillin may have had undiagnosed allergy or hypersensitivity to penicillin antibiotics.

For example: Case #5 experienced Stevens-Johnson Syndrome – which is known to cause otologic complications like hearing loss. (R)

Synergistic contributions (?)

It’s reasonable to hypothesize that, in some of these cases, multiple variables may have synergistically contributed to hearing changes on amoxicillin.

For example: Older age (higher vulnerability to hearing loss); upper respiratory tract & ear infections; co-administered ototoxic drugs; endotoxin secretion by bacteria during treatment; etc.

Recovery from infection (?)

Amoxicillin was obviously prescribed to treat a specific bacterial infection in each of these cases.

That said, there were no data as to whether the patients recovered fully from the conditions for which amoxicillin was administered.

• (If not recovered – this could’ve meant that the infection proliferated and caused inner ear damage due to lack of response.)

Loud noise exposures (?)

We also do NOT know additional information like exposure to loud noises during treatment (can cause hearing loss directly) and vitamin/nutrient status (may increase susceptibility to hearing loss).

For example, a patient may go to a concert during treatment and end up with hearing loss from the concert.

Study limitations

Cases were suspected or reported by healthcare professionals (couldn’t be confirmed by researchers).

Unmeasured & uncontrolled confounds that would negatively affect causation (could lead to exposure or outcome misclassification bias).

For example: one could argue that 5 cases of “deafness” should’ve been excluded on the basis of “ear infection.”

Risk of hearing loss associated with amoxicillin cannot be quantified due to lack of denominator data.

Examining the 13 cases of deafness from amoxicillin monotherapy…

As you’ll see – there are a lot of data lacking in the cases below including: dosages, conditions treated with amoxicillin, medical co-morbidities, other reactions to amoxicillin, and outcomes (whether hearing was regained following amoxicillin cessation).

Case 1: Female, 16-years-old.

• Oral administration
• Dose: 500 mg (twice daily)
• Indication: Tonsillitis
• Time to onset: 2 days (48 hours)
• Outcome: Recovered (hearing returned after cessation)

Case 2: Female. Age N/A.

• Dose, route of administration, indication – unknown.
• Other reactions: Parosmia (loss of smell). Ageusia (loss of taste).
• Outcome: Recovered with sequelae.

Case 3: Female, 77-years-old.

• Dose, route of administration – N/A.
• Indication: Premedication.
• Other reactions: Chest injury, chest pain, seizure, skin abrasion, insomnia, limb injury, overdose, road traffic accident, stress.
• Outcome: Unknown.

This patient was older age AND had many other co-reported reactions – including seizure and injuries from a traffic accident (which could’ve increased susceptibility to hearing loss).

Case 4: Female. Age N/A.

• Dose & indication: N/A.
• Route of administration: Other.
• Other reactions: Condition aggravated. Emotional disorder.
• Outcome: Unknown.

Case 5: Female, 6-years-old.

• Dose & route of admin: N/A.
• Indication: Pharyngitis streptococcal (strep throat).
• Other reactions: Adjustment disorder, anemia, blindness, cellulitis, phlebitis, Stevens-Johnson syndrome.
• Time to onset: 1 day.
• Outcome: Unknown.

This patient had strep throat AND many other serious reactions (e.g. Stevens-Johnson syndrome) which could’ve contributed to the deafness/hearing changes.

Case 6: Male. Age 29.

• Dose: 1 gram per day.
• Route of admin: Oral.
• Indication: N/A.
• Time to onset: 4 days.
• Outcome: Recovered.

Case 7: Female. Age 53.

• Dose: 500 mg per day.
• Route of admin: Oral.
• Indication: N/A.
• Other reactions: Vomiting. Vertigo. Tinnitus.
• Time to onset: 1 day.
• Outcome: Unknown.

Case 8: Female. Age N/A.

• Dose, route of admin, indication: N/A.
• Other reactions: Visual impairment. Abnormal thinking. Amnesia.
• Outcome: Unknown.

Case 9: Sex & Age: N/A.

• Dose: N/A.
• Route of admin: Oral.
• Indication: Otitis externa (outer ear infection).
• Other reactions: Dizziness. Nausea.
• Outcome: Recovered.

Case 10: Female. Age 47.

• Dose: 3 grams per day.
• Route of admin: Oral.
• Indication: Cystitis (unspecified).
• Other reactions: Tinnitus.
• Time to onset: 10 days.
• Outcome: Not recovered.

Case 11: Female. Age 53.

• Dose: 750 mg per day.
• Route of admin: Oral.
• Indication: Chronic sinusitis.
• Other reactions: Nephritis. Acute kidney injury. Pyrexia. Rash.
• Outcome: Recovered.

Case 12: Female. Age 31.

• Dose: 750 mg per day.
• Route of admin: Oral.
• Indication: N/A.
• Other reactions: Ataxia. Muscle twitching.
• Outcome: Not recovered.

Case 13: Female. Age 82.

• Dose: N/A.
• Route of admin: Oral.
• Indication: N/A.
• Time to onset: 7 days.
• Outcome: Not recovered.

Data analysis from the 13 cases of hearing loss…

I took the time to analyze the 13 specific cases in which amoxicillin was the ONLY medication administered at the time of deafness, hearing loss, and/or tinnitus.

Upper respiratory infection (URI) & ear infection

• 4 of 13 cases (30.77%) were confirmed to involve upper respiratory infection or ear infection. These conditions alone may contribute to hearing changes and/or the pathogenic bacteria causing them may react with amoxicillin during treatment to damage hearing.

However, 7 of 13 cases (53.8%) failed to report the specific indication for amoxicillin – meaning the number of patients with URIs and ear infections could’ve been higher.

This means we can only be certain that 2 of 13 cases (15.4%) did NOT involve URI or ear infection.

Hearing recovered? (Y/N)

• Recovered: 5 of 13 (38.46%)
• Not recovered: 3 of 13 (23.07%)
• Unknown: 5 of 13 (38.46%)

It would’ve been helpful to know whether patients experienced “full” hearing recovery back to baseline – but there isn’t enough information provided.

Furthermore, this is arguably impossible to know – as pre-treatment hearing tests would necessitate comparison with post-recovery hearing tests (including testing of ultra-high frequencies which most providers are unable to evaluate.)

2 cases were documented as “positive dechallenges” in which hearing loss reversed (i.e. hearing normalized) quickly upon cessation/discontinuation of amoxicillin.

Co-reported reactions (Significant?)

• 8 of 13 cases (61.54%) involved medically-significant “co-reactions” such as: parosmia, ageusia, seizure, worsening of medical condition, anemia, blindness, Stevens-Johnson Syndrome, vomiting, nephritis, acute kidney injury, pyrexia, rash, ataxia, muscle twitching.

This could indicate that a person had another medical condition that led to his/her hearing changes on amoxicillin OR that they experienced a major hypersensitivity/allergy type reaction to amoxicillin.

High-dose amoxicillin as a cause?

One case involved a 47-year-old woman was taking 3 grams of amoxicillin per day to treat unspecified cystitis.

She noticed significant hearing loss with tinnitus on the 10^th day of treatment.

It’s possible that the high dose of amoxicillin (3 grams) may have reached a threshold at which hearing damage becomes more common/likely (most patients don’t take more than 1500 mg per day).

Moreover, the high dose had been administered for a relatively prolonged duration (10 days).

Because she had zero other significant medical reactions – it’s reasonable to speculate that the high dose of amoxicillin was probably culpable for her hearing loss.

Ototoxic Adverse Drug Reactions: A Disproportionality Analysis Using the Italian Spontaneous Reporting Database (R)

• Author: Barbieri et al. (2019)
• Aim: Analyze adverse drug reaction (ADR) reports describing drug-induced ototoxicity.
• Methods: Evaluate all suspected ADR reports regarding drug-induced ototoxicity in the Italian SRS from 2001-2017 (16-year period) relative to non-cases (other ADRs in same time period). Employ a disproportionality measure with case/non-case methodology.

What were the findings?

Amoxicillin was NOT listed as a medication likely to be ototoxic or cause tinnitus.

There were 3 reports of ototoxicity from amoxicillin monotherapy as an adverse reaction during the 16-year period.

There were 6 reports of ototoxicity from amoxicillin combined with beta-lactamase inhibitor (e.g. clavulanate).

This means that amoxicillin + clavulanate (e.g. Augmentin) may be more likely to cause ototoxicity (hearing loss and tinnitus) than standalone amoxicillin – but neither are significantly associated with ototoxicity.

Drugs Inducing Hearing Loss, Tinnitus, Dizziness, & Vertigo: An Updated Guide (R)

• Author: Altissimi et al. (2020)
• Methods: Perform a comprehensive analysis of audio-vestibular side effects of commercially available drugs based on the British National Formulary, a pharmaceutical reference book that contains a wide range of useful information and advice on prescription and pharmacology.

The biggest limitation associated with this “European Review” is that results are based upon the British National Formulary.

Why is this a limitation? Because the British National Formulary likely does NOT account for adverse reactions reported by patients & medical doctors.

Instead, the British National Formulary likely only contains information about drugs from specific drug manufacturers and/or clinical trials which would fail to account for new information.

What were the findings in this review?

Amoxicillin as a standalone drug was either: (1) omitted from the report (perhaps because it didn’t cause any audio-vestibular reactions) OR (2) not analyzed in isolation (because it isn’t commonly used in isolation).

Amoxicillin when combined with clavulanate (Amoxicillin + Clavulanate) – also known as “Augmentin” or “Co-Amoxiclav” – was documented as causing “vertigo or dizziness.”

Azithromycin & Sensorineural Hearing Loss in Adults (Retrospective Cohort Study) (R)

• Authors: Alrwisan et al. (2018)
• Aim: Determine whether short-term use of azithromycin increases risk of sensorineural hearing loss in adults (18-64 years old) with uncomplicated infections.
• Methods: Compare risk of sensorineural hearing loss in adults treated with azithromycin vs. amoxicillin +/- clavulanate via retrospective cohort analysis of Medicaid claims data (1999-2010).
• Results: 493,774 patients entered the study cohort. Unadjusted incidence rates of SNHL were 38 cases per 10,000 patient years (azithromycin) and 41 cases per 10,000 patient years (amoxicillin +/- clavulanate).
• Conclusion: Risk of sensorineural hearing loss of amoxicillin +/- clavulanate is no different than azithromycin when administered over a short-term for uncomplicated infections in adults.

What are the takeaways from this study?

Neither azithromycin nor amoxicillin (+/- clavulanate) are likely to cause hearing loss in adults when administered over a short-term for uncomplicated infections.

In fact, it seems as though amoxicillin +/- clavulanate may be slightly more likely than azithromycin to cause hearing loss in adults – when administered over a short-term for uncomplicated infection.

Results of this study were consistent with prior research by Etminan et al. who documented similar risk of hearing loss from amoxicillin, macrolides, and quinolones.

Limitations to consider…

It was reported that patients taking amoxicillin +/- clavulanate were significantly more likely to have diagnoses of: (1) otitis media and (2) sinusitis – both of which may cause hearing loss regardless of antibiotic treatment.

Had researchers controlled for diagnoses of otitis media and sinusitis – rates of hearing loss may have been significantly lower on amoxicillin +/- clavulanate than azithromycin.

Azithromycin doses in this study were significantly lower than those used in studies showing hearing loss and treatment duration was significantly shorter – therefore high-dose and/or long-term azithromycin might be more problematic with regards to hearing. (Though it’s possible the same could be said for amoxicillin.)

Observational studies like this are limited by:

• Lack of randomization
• Imbalances in baseline characteristics between exposure groups
• Adherence differences between groups; possible hearing loss before index date (due to undercoding of medical conditions)
• SNHL definition used was dependent upon patients seeking medical care for hearing loss (mild cases may have been unreported)
• Repeated courses of short-term treatment not evaluated (e.g. patients with recurrent infections

Risk of sensorineural hearing loss with macrolide antibiotics (Nested case-control study)

Etminan et al. (2017)

“A significant association between SNHL (sensorineural hearing loss) and macrolide use was likely due to confounding by indication for antibiotic treatment because risk was also observed with fluoroquinolones and amoxicillin, antibiotics with no known ototoxic potential.” (R)

• Researchers conducted a retrospective nested case-control study to determine the relationship between macrolide antibiotic use and hearing loss.
• Data analyzed included reports between 2006-2014 (8 years) in a health claims database – among individuals ages 15-60 who used macrolides vs. other antibiotics (amoxicillin & fluoroquinolones) – and developed hearing loss.
• A total of 5,989 cases of hearing loss were reported vs. 59,890 controls (no hearing loss).
• If the results of this study accurately represent the effects of macrolides, fluoroquinolones, and amoxicillin – then one of the following must be true: (1) none of these antibiotics commonly cause hearing loss OR (2) amoxicillin causes hearing loss at rates similar to azithromycin and fluoroquinolones.
• Limitations of this study: health claims data (reliant on quality of reported diagnoses); no access to actual SNHL records; unknown treatment compliance; confounding variables excluded (e.g. otitis media, pharyngitis, sinusitis); possible residual confounding; imbalance of baseline characteristics between cases and controls.
• Results did show an increased risk of hearing loss with macrolide antibiotics but similar risks were observed with amoxicillin and fluoroquinolones – and researchers suspect that there’s likely: “a shared mechanism other than ototoxicity by which antibiotic prescriptions are associated with sensorineural hearing loss.”
• A dose-response relationship was also observed which might further explain severity of infection as a risk factor for sensorineural hearing loss.

Bisht & Bist (2011): Report that penicillin antibiotics like piperacillin and amoxicillin can cause “vertigo” or “dizziness” as a side effect. That said, amoxicillin was NOT documented as drugs capable of causing “tinnitus” or “hearing loss” as a side effect. (R)

StatPearls (2021): StatPearls is a trusted resource for medical professionals containing updated data on various medications. As of 2021 – there are zero strong data to suggest that amoxicillin or amoxicillin-clavulanate (Augmentin) cause ototoxicity, hearing loss, or tinnitus.

• Amoxicillin: Ototoxicity, hearing loss, and tinnitus are NOT documented as a side effect or adverse reaction to amoxicillin – even in rare cases. That said, it’s possible that hearing changes could occur secondary to a rare reaction like: hypersensitivity/allergy; seizure; hepatotoxicity/nephrotoxicity; etc. (R)
• Amoxicillin-Clavulanate (Augmentin): Ototoxicity, hearing loss, and tinnitus are NOT documented as a reaction to amoxicillin-clavulanate – even as “rare” reactions. (It’s possible that hearing loss or tinnitus might occur secondary to a reaction like Stevens-Johnson syndrome or seizure – but this would not be a direct effect of the medication). (R)

Expert Opinions: Amoxicillin & Ototoxicity (Hearing Loss & Tinnitus)

Below are opinions from experts on the topic of antibiotics and ototoxicity, hearing loss, and tinnitus.

Although Neil Bauman is not a medical doctor and has been accused of using the term “ototoxic” too liberally – he has done more actual research than most (evaluating datasets of adverse reaction reports that nobody checks) and I value his risk analysis.

Neil Bauman (HearingLossHelp)

In my research of ototoxic drugs – I like to always check in with Neil Bauman because he’s an independent expert on the ototoxic potential of many common medications. (R1, R2)

He’s written a book called “Ototoxic Drugs Exposed” that ranks likelihood of ototoxic reactions with various medications based on the ratio of audio-vestibular adverse events to total number of prescriptions.

Essentially, Neil digs deep through post-marketing FDA surveillance data for ototoxic-like reactions and assigns each medication a risk number from “1” (low risk) to “5” (extreme risk).

Initially, Neil was of the opinion that “amoxicillin is one of the very few [antibiotics] that is not ototoxic” – but this was back in 2006.

His views have since changed based on new data indicating that amoxicillin might be ototoxic.

He also suggests that Augmentin (Amoxicillin-Clavulanate) can cause “hearing loss, tinnitus, dizziness, vertigo, and other vestibular disorders.” Neil states that “amoxicillin really is ototoxic to some degree” – despite this being relatively unknown for a long-term.

Most of the anecdotes Neil shares, however, are specific to Augmentin (amoxicillin-clavulanate) – not amoxicillin (standalone) which could be due to the fact that: (1) Augmentin is more commonly prescribed OR (2) Amoxicillin (standalone) is significantly less ototoxic than Augmentin.

Nonetheless, I think Neil considers amoxicillin to be “mildly” ototoxic (meaning most people shouldn’t have an issue with it).

Dr. Stephen Nagler (MD)

A forum member on TinnitusTalk.com asked Dr. Nagler which combination would be lower risk (regarding tinnitus): (1) azithromycin (1g); (2) doxycycline (200 mg/day for 7 days); (3) amoxicillin (500 mg, t.i.d. for 7 days).

His response: “None of the three causes auditory damage. In terms of tinnitus, you’d probably be OK with any of them, but I’m just not a huge fan of azithromycin in that regard. Between the other two, I guess I’d go with the amoxicillin.” (R)

The above question was posted and answered in April 2018.

This suggests that Dr. Nagler – a medical doctor with tinnitus who has researched ototoxic potential of many drugs – thinks that amoxicillin is probably the least risky antibiotic with regard to tinnitus.

He plainly states that amoxicillin does not cause auditory damage (i.e. ototoxicity).

Although I’m not a medical doctor – I agree with Dr. Nagler’s recommendation here, although doxycycline is generally a very safe choice as well.

Anecdotes of Amoxicillin Hearing Loss & Tinnitus

With anecdotes, it’s important to realize that hearing loss and/or tinnitus may have occurred regardless of whether amoxicillin was administered.

Additionally, the hearing loss and/or tinnitus may have resulted from infection-related damage or endotoxin-like compounds during treatment rather than from the medication directly.

Moreover, many variables are unknown in most anecdotes: (1) amoxicillin dosage; (2) preexisting conditions; (3) diet & lifestyle; (4) noise exposure during treatment; (5) liver/kidney function; (6) allergy/hypersensitivity to penicillin; (7) infection specifics (bacteria, location, severity); (8) other medications administered.

We also don’t have follow-ups from most anecdotes regarding whether hearing eventually normalized weeks or months after completion of amoxicillin or Augmentin therapy.

Anecdotes from HearingLossHelp (Neil Bauman)

Note: None of the above are for standalone amoxicillin – all involve Augmentin.

Anecdotes from TinnitusTalk.com

The consensus opinion over at TinnitusTalk forum is that amoxicillin is probably the safest antibiotic to take if concerned about tinnitus and/or hearing loss.

Many of these individuals were asked whether the tinnitus spikes associated with amoxicillin “subsided” and many did not reply back – so in all likelihood the spikes did subside.

Moreover, of all these cases, it’s extremely difficult to establish plausibility (that amoxicillin was the likely cause of tinnitus or hearing loss).

Nearly all cases have preexisting tinnitus/hearing loss from other causes – and/or involved additional substances that could’ve caused tinnitus/hearing loss.

(We also don’t know whether the tinnitus resulted from “toxicity” or changes in perception/neurochemistry and/or if it subsided in time).

Note: I didn’t document “every single case” on this forum – but covered most of them.

Anecdotes from Reddit

Tinnitus “spiking” during treatment with amoxicillin or Augmentin should not necessarily be considered alarming – as this could be due to perceptual changes, changes in neurochemistry, altered inflammatory mediators, interaction between the medication and pathogens, etc.

Several of these cases involved a tinnitus “spike” during treatment followed by reversion back to baseline (pre-treatment) status. Additionally, many of these individuals had preexisting tinnitus and/or upper respiratory infections (which complicates things).

Tinnitus resolved after taking Augmentin? (Anecdote)

A 23-year-old male claims to have gotten tinnitus in his right ear ~3 years ago after a horrible “flu” that left both of his ears plugged for a month. (R)

He didn’t take any antibiotics – as he thought they’d wreak havoc on his gut so avoided them at all costs (this is logical if diagnosis is influenza – as the flu is a virus).

Eventually got a skin infection with painful cysts all over upper legs/buttocks and got a ~2-week prescription for Augmentin which took care of the cysts.

In his words: “It also miraculously made the high-pitched ringing in my right ear completely disappear. I can’t even hear it in a quiet room.”

He then asks whether anyone else has cured their tinnitus with antibiotics.

How did the tinnitus “reverse” here? (Hypothesis)

Alterations in neurochemistry and possibly reduction in certain inflammatory mediators.

Perhaps the flu left part of his ear/brain in a state of “chronic inflammation” and the Augmentin reversed it.

This should be considered a rare occurrence – as I haven’t found another case like this.

It also remains unclear as to whether the tinnitus eventually “returned” (e.g. months after the Augmentin).

Main takeaways from the scientific literature & anecdotes (re: Amoxicillin & hearing loss, tinnitus, ototoxicity)

• Neither amoxicillin nor Augmentin commonly cause hearing loss or tinnitus – and there’s zero evidence of direct “ototoxicity” (damage to the ears) resulting from these medications (on average).
• Amoxicillin and Augmentin may directly cause hearing loss, tinnitus, or ototoxic reactions in rare cases such as a consequence of allergic or hypersensitivity reactions.
• In the (rare) subset of patients who experience allergic or hypersensitivity reactions – about half of these patients (50%) will regain normal hearing after treatment is stopped.
• Most people who experience hearing loss from amoxicillin and Augmentin also experience other significant adverse events during treatment.
• Many individuals who notice a “spike” in tinnitus during treatment have preexisting tinnitus or hearing problems – and/or an “upper respiratory tract” infection. (Reports of new tinnitus onset from amoxicillin or Augmentin are rare.)
• Amoxicillin and Augmentin may indirectly contribute to hearing loss, tinnitus, or ototoxicity via: (1) interaction with pathogen; (2) secretion of endotoxin-like compounds by bacteria during treatment; (3) immunomodulation and/or immune response to bacteria.
• In most cases, hearing loss, tinnitus, and ototoxicity experienced while taking amoxicillin or Augmentin are probably NOT from the amoxicillin or Augmentin – instead are from pathogen-induced damage (e.g. ear damage from a bacterial infection) or an exaggerated inflammatory immune response to infection.
• Amoxicillin may be ~2-fold less likely to cause hearing loss and tinnitus than Augmentin (suggested by one study).
• High-dose amoxicillin and Augmentin – taken for an extended duration may increase risk of hearing loss and/or tinnitus relative to short-term treatment.
• One study showed that amoxicillin causes hearing loss at similar rates to macrolides (e.g. azithromycin, erythromycin, clarithromycin) and fluoroquinolones – indicating that hearing loss may be either: (1) more common on amoxicillin than suspected OR (2) less common with macrolides and fluoroquinolones than believed – but there were some limitations (e.g. participants with URIs not excluded).
• Hearing loss and tinnitus can be caused by upper respiratory infections (URIs) such as: (1) ear infection; (2) sinus infection; (3) throat infection – and emerge during amoxicillin or Augmentin treatment (leading the individual to believe it was the medication that caused it instead of the infection).

How could amoxicillin cause hearing loss, deafness, and/or tinnitus? (Mechanisms)

Unknown. There’s not really any scientific consensus regarding how amoxicillin might induce ototoxicity and cause hearing loss, deafness, or tinnitus.

According to Russom et al. (2020), drug-induced ototoxicity or deafness can result from “a unique susceptibility of the injured tissue to the drug, accumulation of the drug within the organ, or a combination of both factors.”

Russom et al. added:

“Inner ear injury may result from reversible inhibition of normal physiological functions such as endolymph formation, which if inhibited for prolonged periods of time results in degeneration of tissue dependent upon the particular physiological function. Direct toxic effects on sensory end organs (i.e. hair cells) also play a role in drug-induced toxicity.”

The strength of association between amoxicillin and 42 cases of deafness was weak as the disproportionality measure (information component – IC value) was negative (IC = -1.35).

This indicates that: (1) either the reaction is extremely rare OR (2) might be masked by other commonly reported reactions related to amoxicillin like allergic or hypersensitivity reactions.

There was no significant dose-response relationship between amoxicillin and deafness – in that higher doses were not more likely to cause deafness than standard doses.

That said, amoxicillin does seem to cause severe hearing loss in specific cases – evidenced by severe hearing loss during amoxicillin monotherapy and reversibility of the hearing loss following amoxicillin withdrawal.

In summary – scientific professionals believe amoxicillin does cause hearing loss in a subset of cases (as evidenced by onset after amoxicillin initiation and reversal after amoxicillin cessation) – but they aren’t sure of the specific reason(s) why this occurs.

Drew’s hypotheses (How Amoxicillin Causes Hearing Loss and/or Tinnitus)

I think that amoxicillin and/or Augmentin could cause hearing loss and/or tinnitus in many ways – and it’s likely specific to the individual.

Allergy or hypersensitivity reaction: Most cases of hearing loss on amoxicillin seem to be accompanied by other significant adverse reactions. A subset of patients who experience amoxicillin allergy or hypersensitivity may develop hearing loss as a result of an allergic reaction – rather than as a result of direct ototoxic insult from the drug.

Bacterial infection: Directly damages the ears prior to treatment.

Immune-mediated inflammation: In response to: (1) untreated infection (pre-amoxicillin); (2) amoxicillin-related immunomodulation; (3) secretion of endotoxin-like compounds during treatment by bacteria. Secretion of certain inflammatory cytokines/chemokines and mediators at or above a certain threshold could create inner ear inflammation and inflict damage.

Interaction between amoxicillin, bacteria, and/or immune system: This is a common scenario among patients with ear, nose, or throat infections (upper respiratory infections).

1. Amoxicillin exerts a bactericidal effect (killing bacteria responsible for the infection).
2. As bacteria are dying from amoxicillin therapy, they secrete toxic compounds (e.g. endotoxins) which can trigger an immune response (cytokine/chemokine secretion).
3. Toxic compounds secreted by dying bacteria can be directly toxic – but the immune reaction to these compounds (cytokine/chemokine release) can also increase inflammation in the inner ear – potentially inflicting damage (resulting in hearing loss and/or tinnitus).

Physiologic alterations: These would be more significant at high doses or above a certain dosing threshold (specifically: above a certain dose to body size ratio) or if a person has liver or kidney impairment (such that amoxicillin accumulates and reaches abnormally high systemic concentrations that may induce toxic effects.)

• Altered mucosa: Mucus within the ear, nose, or throat area might change in thickness or flow rate – such that it builds up within the ears or eustachian tubes and causes tinnitus or hearing loss (this is more likely to be caused by infection than antibiotics).
• Commensal bacteria “die”: Death of commensal bacteria in the inner ear or in tangential areas (e.g. nasopharynx) may trigger some sort of localized inflammatory response and subsequent hearing change.
• Blood pressure changes: Amoxicillin may alter blood pressure during treatment.
• Brain activity changes (neurotransmission, blood flow, etc.): Amoxicillin may affect blood flow and neurotransmitter concentrations in the brain – along with regional activation, causing one to perceive tinnitus or a worsening of preexisting tinnitus. (Essentially this is creating a “perceptual change” during treatment – but not “objective” tinnitus.)

Amoxicillin interacts with other substances (medications, drugs, supplements, alcohol/caffeine, etc.): It’s possible that co-administration or simultaneous systemic circulation/presence of another substance – even if just caffeine, nicotine, or alcohol – could trigger an interaction wherein a person becomes more susceptible to hearing loss or tinnitus during treatment.

Amoxicillin interacts with medical conditions: Amoxicillin might interact with a preexisting medical condition in a way that triggers tinnitus and/or hearing loss. (This would be nearly impossible to confirm.)

Secondary to “rare” adverse reactions:  For example, someone might develop Stevens-Johnson syndrome or seizure and develop hearing loss or seizures as a reaction to those reactions or as a subcomponent of the specific reaction. (Most of these are allergy & hypersensitivity-related reactions.)

Note: Select cases may involve multiple aforementioned mechanisms: (1) at distinct time points (e.g. direct inner ear damage from bacteria – then amoxicillin hypersensitivity reaction) and/or (2) simultaneously or slightly overlapping in time (e.g. endotoxin-induced damage + physiologic changes from antibiotic treatment + abnormal immune response).

Other ways amoxicillin or Augmentin could cause hearing loss & tinnitus…

• Acid reflux (?): If amoxicillin or Augmentin trigger extra-esophageal reflux (e.g. laryngopharyngeal reflux) then stomach acid could get into the inner ear, cause inflammation, and possibly tinnitus with hearing changes due to eustachian tube dysfunction.
• Additives & toxins: Certain manufacturers of amoxicillin or Augmentin may have poorer quality control relative to others and/or contain additives that others do not. It’s possible that otic-related side effects are less common with specific manufacturers.
• Expired (?): Occasionally individuals “save” leftover or unused antibiotics and administer them at a later date. Generally expired medications make the medication less effective but may also increase risk of adverse reactions due to chemical changes over time.
• Nocebo-like effect: This is limited to tinnitus. Someone might really fear tinnitus from amoxicillin and notice new tinnitus onset or worsening of tinnitus. In most cases this would be due to anxiety-related changes in neurochemistry and/or heightened awareness (causing the person to believe “phantom sounds” in a quiet room are tinnitus.)
• Psychological stress: Psychological stress during treatment may increase risk of hearing loss and/or tinnitus for a variety of reasons. That said, stress doesn’t typically cause ear damage. It’s more likely to cause nocebo-like effects associated with hyper-analysis of one’s hearing and believing “phantom sounds” are tinnitus.
• Yeast overgrowth (?): Antibiotics kill off commensal bacteria which creates a perfect environment for yeast (e.g. Candida) to thrive – often growing in excess. If you are immunocompromised, it’s possible that yeast could spread to the inner ear and create a fungal infection accompanied by hearing loss and tinnitus.

Risk factors for hearing loss & tinnitus on Amoxicillin or Augmentin…

Included below are risk factors for developing hearing loss and/or tinnitus while taking amoxicillin and Augmentin.

Note: These risk factors assume you are NOT allergic or sensitive to amoxicillin or Augmentin. If you have an underlying allergy or sensitivity to these medications – this may account for onset of hearing loss and tinnitus.

1. Upper respiratory infection (ears, nose, throat): An ear infection is the biggest risk factor for experiencing hearing loss and tinnitus with amoxicillin and Augmentin. Why? In brief, pathogens create inflammation (directly and indirectly) within the ear and this can cause damage. This inflammation can briefly increase during treatment with antibiotics.
2. Severe infection: Individuals with severe infections may endure more infection-related damage before treatment and during treatment (higher concentrations of endotoxin-like compounds secreted during treatment). Less severe infections are less likely to trigger otic reactions.
3. Co-administered substances: Administering any other substance(s) with amoxicillin or Augmentin could increase risk of otic reactions (e.g. tinnitus, hearing loss, etc.). This includes things like: caffeine, alcohol, cannabis, other antibiotics, OTC meds, and prescription medications. In some cases, hearing loss and tinnitus likely result directly from the co-administered substance (e.g. ear drops for an ear infection) – without any influence of amoxicillin.
4. Additional medical conditions: If you have any significant preexisting medical conditions: high blood pressure, diabetes, autoimmune conditions, organ dysfunction, etc. – your risk of experiencing tinnitus and hearing loss during treatment may increase.
5. Preexisting tinnitus & hearing loss: Many people with preexisting tinnitus will notice “spikes” in tinnitus from amoxicillin and Augmentin due to drug-mediated perceptual changes. When the drug is discontinued the spikes tend to normalize. Any preexisting tinnitus and/or hearing loss puts you at greater risk of tinnitus/hearing loss exacerbation during treatment.
6. Past tinnitus or hearing loss with amoxicillin: This should be obvious – but if you’ve experienced tinnitus and/or hearing loss in the past from amoxicillin or Augmentin – you may be at increased risk of experiencing the same reactions with future usage of these medications.
7. High-dose administration: One study noted that risk of hearing loss was higher with high-dose administration of antibiotics than lower dose. This makes logical sense due to the fact that higher dosages alter physiology to a greater extent than lower doses.
8. Long-term administration: Long-term administration of amoxicillin or Augmentin may increase risk of hearing loss and/or tinnitus relative to short-term treatment.
9. Older age: One study documented ~55 as the “median” age at which “deafness” occurred on amoxicillin. Though plenty of cases still involved young persons (~39%) – most involved older individuals probably due to age-related physiological degradation (damage susceptibility).
10. User-specific pharmacokinetics: Amoxicillin may differ between persons in pharmacokinetics and this could influence odds of hearing loss and tinnitus.

• Administration details: With food vs. empty stomach; time of administration (circadian interactions); hydration level; dosing frequency (once, twice, thrice daily). Note: Improper administration such as taking one large dose vs. spacing the dosages may increase risk of adverse reactions.
• Kinetic variables: AUC (area under the curve); bioavailability; clearance/elimination rate; peak concentrations.
• Organ function: Individuals with impaired kidney and/or liver function may be more susceptible to ototoxicity.

11. Genetic susceptibility: Certain combinations of genes may influence susceptibility to developing tinnitus and/or hearing loss while using amoxicillin and Augmentin.
12. Loud noise exposure: If you are exposed to loud noise during treatment with amoxicillin or Augmentin – and develop tinnitus/hearing loss, it’s probably mostly from the noise exposure (but the medication may have made your ears more vulnerable to damage).
13. Nutrient deficiencies: Low concentrations of certain vitamins/nutrients may increase one’s risk of hearing loss and/or tinnitus during treatment.
14. Immune function: Individuals with autoimmune disease or those who are immunocompromised may be more likely to experience ototoxic reactions to amoxicillin than those with normative immune function. Atypical immune activation during treatment might increase risk of otic reactions as well.
15. Female (?): There’s some evidence to suggest that females are more likely to experience hearing changes on amoxicillin than males. That said, I personally can’t think of many logical mechanisms by which this would be true. Perhaps something hormonal or nutritional. Possibly dose to bodyweight ratio (resulting in females receiving higher “standard doses”). I suspect males may be less likely to complain/report otic reactions.

How to reduce likelihood of tinnitus & hearing loss on amoxicillin & Augmentin…

There’s no “proven” methods to reduce tinnitus & hearing loss risk from medications.

Below are my thoughts – which should NOT be interpreted as medical advice.

Consult a medical doctor and verify safety of these methods before implementing.

Use minimal effective dose

Take the lowest dose of amoxicillin or Augmentin possible to treat your infection.

(Obviously don’t take less than what’s prescribed – as you need to treat the infection.)

Use for minimal necessary time

Don’t take amoxicillin or Augmentin longer than necessary.

Ask your doctor how long you’ll need to take the medication and don’t take for longer than required.

Avoid unnecessary substances

Any substance that’s medically unnecessary should be avoided during treatment due to interaction risk (pharmacokinetic & pharmacodynamic interactions) or inducing physiologic alterations that increase susceptibility to toxicity.

Ask a doctor and pharmacist about possible interactions of amoxicillin or Augmentin with any medications or supplements that you take.

Otoprotective agents (during & after treatment)

Rule out interactions with amoxicillin and Augmentin before administering any otoprotective agents.

(Also don’t take these with amoxicillin – wait at least 2-4 hours after to avoid kinetic alterations.)

Note: Below are affiliate links – helping me earn a tiny comission. Price is the exact same regardless of whether you buy through my links.

• Vitamin D3
• Vitamin C
• Alpha-GPC
• Alpha Lipoic Acid
• NAC (N-acetyl-cysteine) or Glutathione
• Magnesium (threonate, glycinate, citrate)
• Multivitamin
• Ubiquinol
• Taurine
• Calcium-d-glucarate
• Melatonin (night-only)
• Vitamin A
• Vitamin E

Important: Do NOT assume that the above substances don’t interact with amoxicillin or any medical condition that you have. Confirm safety of co-administration with a medical doctor and pharmacist and follow their administration recommendations.  You should be able to take these after amoxicillin safely.

Protect hearing

Zero loud noise exposure during treatment – and possibly for 2-4 weeks after.

Ears may be more vulnerable to noise-induced damage while on amoxicillin.

Use noise-reduction earmuffs or earplugs during treatment.

Manage stress

Do whatever keeps you relaxed and at peace during treatment.

Warm showers/baths, massages, meditation, breathing exercises, etc.

Quality sleep

Do whatever helps you get quality sleep.

Avoid phone, do something relaxing, eat enough food, etc.

Sleep helps protect the body from damage.

What to do if you notice tinnitus and/or hearing loss on amoxicillin or Augmentin?

Inform your medical doctor and/or pharmacist IMMEDIATELY – zero hesitation and talk about potential solutions to this issue.

Tinnitus may be reversible such that it may completely fade after amoxicillin treatment ends.

Hearing loss may be permanent and be a sign that amoxicillin is incompatible with your physiology (due to allergy or hypersensitivity, etc.).

That said, hearing loss may also be more of a byproduct of the infection being treated than the medication being used to treat.

Still, if hearing loss occurs – tell your doctor right away.

There are usually a few alternative medications you’ll be able to try instead (if amoxicillin is the suspected cause of your hearing loss).

A doctor may recommend that you take a corticosteroid if hearing loss or deafness occurs – and this is sometimes a very effective way to restore hearing in some individuals.

I’d personally supplement with otoprotective agents during the remainder of treatment (these might help with reversal of hearing loss and/or promotion of hearing recovery/restoration).

How can you know if amoxicillin caused your tinnitus and/or hearing loss?

It’s impossible to know with 100% certainty whether amoxicillin caused your tinnitus and/or hearing loss due to the confound of infection and potential allergy/hypersensitivity.

I would hypothesize that you can be relatively certain that amoxicillin or Augmentin are to blame if you:

• Did NOT have an upper respiratory infection (ear, nose, throat)
• Are NOT allergic or sensitive to penicillin, amoxicillin, or clavulanate
• Were NOT exposed to loud noises (e.g. music, sirens, construction, fireworks, etc.) during treatment
• Were NOT highly stressed during treatment
• Did NOT have significant sleep problems during treatment
• Do NOT have preexisting tinnitus or hearing issues
• Used amoxicillin or Augmentin are conventional doses for standard durations
• Have no significant preexisting medical conditions (e.g. autoimmune conditions, organ impairment, etc.)
• Do NOT use other medications/substances that may have interacted with amoxicillin
• Did NOT experience any other adverse reactions during treatment

Moreover, if you had a non-severe (i.e. mild) infection that did NOT affect the upper respiratory tract – and you developed hearing loss and/or tinnitus – it was more likely from the medication.

(Even then, it’s possible that endotoxin-like compounds or cytokines could circulate up to the inner ear via bloodstream and cause damage – but this would be less likely in non-severe infections.)

My experience taking Augmentin…

I took a 5-day course of Augmentin (amoxicillin + clavulanate) (b.i.d.) to treat what may have been a sinus infection or ear infection.

Because I am naturally paranoid about ototoxic potentials of antibiotics, I was hesitant to take the medication – but decided the risks of not taking it outweighed the risks of taking it.

During treatment I experienced ZERO significant tinnitus or hearing changes throughout treatment.

I experienced a major increase in “acid reflux” (burning sensation in upper chest and throat) and “dizziness” during treatment (the dizziness may have been more related to the reflux).

My sleep quality may have worsened slightly (relative to baseline) – and I had some really weird dreams, but these could’ve been unrelated to Augmentin.

Why would Augmentin be more likely than amoxicillin to cause hearing loss and/or tinnitus?

There’s no clear evidence that Augmentin is definitively more likely to cause hearing loss and/or tinnitus than amoxicillin.

One could argue that because Augmentin is generally prescribed to treat more severe upper respiratory infections (URIs) than amoxicillin – that tinnitus and hearing loss are more common with its administration (on average).

• (This would be a byproduct of infection severity disparities – not the difference in medications.)

That said, there are some data indicating that rates of hearing loss and/or tinnitus are ~2-fold more common with Augmentin than amoxicillin.

• (Keep in mind that there were some limitations associated with this research – so don’t assume it’s accurate.)

Assuming the research suggesting that Augmentin (Co-amoxiclav) is accurate – then how could Augmentin cause higher rates of hearing loss and tinnitus than amoxicillin?

Clavulanate potassium (clavulanic acid)

This is a Beta-lactam drug that functions as a mechanism-based Beta-lactamase inhibitor (whereby it binds to the beta-lactamase active site of bacteria and inactivates the enzyme).  Clavulanate potentiates the bactericidal actions of amoxicillin.

• Additional physiological effects (?): The clavulanate component may alter homeostatic physiology to a greater extent than standalone amoxicillin.
• Amoxicillin dosage & potency (?): The dosage of amoxicillin included in a typical Augmentin preparation may be higher than a dosage prescribed with standalone amoxicillin. The potency of amoxicillin is increased as a result of the clavulanate component.
• I.D. dosing vs. T.I.D. dosing (?): Augmentin is typically taken twice daily – whereas amoxicillin is often administered three times per day. This disparity in dosing frequency could be a reason as to why reactions are more common with Augmentin.
• Allergy or sensitivity to clavulanate (?): It’s possible that a subset of individuals have an allergy/sensitivity only to the clavulanate component of Augmentin – and thus experience rare adverse reactions that wouldn’t occur with standalone amoxicillin.
• Synergism between amoxicillin & clavulanate (?): There may be some synergistic effect between amoxicillin and clavulanate that makes individuals more sensitive to ototoxic events (particularly those with preexisting sensitivities or allergies).

Note: None of the above reasons are scientifically-validated. These are just hypotheses that should only be considered if Augmentin truly causes more hearing loss/tinnitus than amoxicillin.

My final thoughts on amoxicillin & hearing loss, tinnitus, ototoxicity…

Included below is a summary of my thoughts on amoxicillin and hearing loss, tinnitus, and ototoxicity.

Amoxicillin does NOT cause hearing loss for most users (99%)

In most patients, no change in hearing occurs during amoxicillin treatment.

Among those who do experience hearing loss during treatment – a subset of those patients may have experienced the hearing loss regardless of whether amoxicillin was administered – due to:

• Co-administered medications (e.g. ototoxic drugs)
• Preexisting medical conditions & symptom flares
• Severe bacterial infection (advanced stage & untreated for weeks/months)
• Specific bacterial infection (certain infections may be more likely to inflict damage)
• Specific infection location (e.g. ears, upper respiratory tract)
• Older age (age-related physiological susceptibility)

Another subset of patients who experience hearing loss on amoxicillin probably had an undiagnosed amoxicillin allergy or hypersensitivity (this is more common in patients who’ve never used amoxicillin or penicillin antibiotics.)

Amoxicillin can cause hearing loss in rare cases

There is some evidence that amoxicillin can cause hearing loss in a minority of patients (likely less than 0.00001%).

One might argue that hearing loss is underreported with amoxicillin and therefore the data are skewed such that hearing loss is more common from amoxicillin than reported.

However, researchers could only find 94 cases of hearing disorders plausibly related to amoxicillin from 1972 to 2020 (48-year period) – and many of these cases involved co-administered ototoxic drugs.

Sure there are limitations with the aforementioned research, but even if we were to assume that amoxicillin caused hearing loss in 94 people each year in the U.S. – the overall likelihood of amoxicillin causing hearing loss would remain extremely low.

Let’s consider the fact that there were 30 million amoxicillin prescriptions filled in the U.S. for 2018.  Let’s assume that 5 million of the 30 million prescriptions were either: (1) to the same individual or (2) never administered.

This would indicate that 0.0004% of users experienced hearing change on amoxicillin per year – this factors in co-administered ototoxic drugs.

When considering only standalone amoxicillin administration in patients without penicillin allergy – the likelihood of amoxicillin directly causing hearing loss is almost zero.

Hearing loss from amoxicillin is usually accompanied by other reactions

Most patients who develop hearing loss or deafness on amoxicillin generally have other additional significant adverse reactions during treatment such as: parosmia, ageusia, seizure, worsening of medical condition, anemia, blindness, Stevens-Johnson Syndrome, vomiting, nephritis, acute kidney injury, pyrexia, rash, ataxia, muscle twitching.

Hearing loss from amoxicillin is often reversible

In the minority of patients who experience hearing loss on amoxicillin, abrupt discontinuation of amoxicillin may result in normalization of hearing such that hearing reverts back to pre-amoxicillin function.

Russom et al. reported: “deafness was reversible in about half of the cases.”

That said, it remained unclear as to whether “reversible” meant “full recovery” of pre-amoxicillin hearing or merely “non-deaf” status.

Hearing loss from amoxicillin is sometimes permanent

Among the small percentage of patients who experience hearing loss or deafness from amoxicillin – this becomes permanent in about 50% of cases.

It is thought that abrupt discontinuation of amoxicillin after onset of hearing changes increases likelihood of reversibility (i.e. full or partial hearing recovery) – relative to continuing amoxicillin after hearing loss.

Administration of a corticosteroid immediately after hearing loss onset (along with amoxicillin discontinuation) may also increase odds of hearing recovery.

High dose = higher risk (?)

Although researchers claim that there was no dose-dependent effect on risk of hearing loss from amoxicillin – I found one isolated case in which a 47-year-old woman developed irreversible hearing loss and tinnitus after taking high-dose amoxicillin monotherapy.

This was the ONLY case in which: (1) time to hearing loss onset was relatively long (~10 days) compared to ~2 days (the average); (2) no major co-reactions occurred; (3) there was no URI or ear infection.

For whatever reason, this individual had been taking a 3 gram (3000 mg) dose per day (above the maximum for most dosing recommendations).

For example: Infectious Disease Management Program at UCSF recommends 80-90 kg/day for high-dose regimens and using a maximum dose of 2000 mg per day. (R)

If this woman was relatively petite and/or had impaired liver/kidney function – amoxicillin concentrations may have reached a toxic threshold at 3 grams, particularly when administered for over 10 days.

Note: It may be that in those susceptible to hearing loss – high doses yield worse outcomes (e.g. more severe hearing loss & lower likelihood of reversibility).

Tinnitus risk unclear (but likely low)

Most research focused on whether amoxicillin caused ototoxicity, hearing loss, and deafness – not necessarily tinnitus.

Although tinnitus often co-occurs with hearing loss – it can occur as a standalone effect that’s completely unrelated to hearing damage (i.e. ototoxicity).

Sometimes tinnitus can emerge simply as a result of transient inflammation or neurochemical changes during antibiotic treatment.

Most tinnitus cases were transient such as ear ringing during treatment followed by normalization (no tinnitus) after treatment ended (e.g. days or weeks later).

Anecdotal reports suggest that tinnitus risk is slightly higher with Augmentin (Amoxicillin + Clavulanate) than Amoxicillin.

• (This is consistent with research by Barbieri et al. in which ototoxicity occurred ~2-fold more often when Amoxicillin was combined with a Beta-lactamase inhibitor.)

That said, nearly every case of “tinnitus” I found related to amoxicillin and Augmentin had many confounding variables including: preexisting tinnitus!

This makes it extremely difficult to interpret whether amoxicillin and Augmentin are actually causing an objective tinnitus spike (via the inner ear) OR merely a change in the perception of preexisting tinnitus (via the brain) that makes it seem “louder.”

Safest antibiotic for hearing concerns (?)

Many consider amoxicillin (standalone) to be the single safest antibiotic for individuals (devoid of penicillin allergy/sensitivity) with concerns about hearing loss and tinnitus during treatment.

Why? There’s no proof that it’s directly ototoxic and it’s been used at a high rate (millions of prescriptions per year) since the 1970s without any convincing data that it causes hearing loss and/or tinnitus in most users.

I won’t go as far as to state that it’s the single safest antibiotic for hearing concerns – because this is likely user-specific based on myriad variables.

• (An argument could be made for doxycycline here as a result of its potent anti-inflammatory action.)

Over the past 10 years about 200M prescriptions have been filled for amoxicillin – and only 13 cases of “deafness” have been plausibly linked to standalone amoxicillin in an in-depth systematic review.

Assuming these data are relatively accurate, this would mean that risk of “deafness” from amoxicillin is ~0.0000065%. (This is about 1.3 cases per 20,000,000 prescriptions.)

Tinnitus probably occurs at a higher rate than “deafness” with amoxicillin and Augmentin due the fact that many variables can cause tinnitus during treatment (including modulation of neurochemistry and inflammatory mediators).

Risk of untreated infection outweighs risk of otic reactions…

In most cases, the risk of an untreated infection significantly outweighs the risk of potential otic reactions to amoxicillin and Augmentin.

If otic reactions occur (e.g. tinnitus, hearing loss, etc.) – they usually emerge between 1-18 days of starting treatment (mean: 3 days).

Moreover, there are generally other antibiotics that can be substituted for amoxicillin with good efficacy if necessary.

Lastly, risk of hearing damage and tinnitus are significantly higher with an untreated infection relative to amoxicillin or Augmentin treatment.

Have you experienced hearing loss and/or tinnitus from amoxicillin or Augmentin?

If so, feel free to share your experience in the comments section.

• For the sake of thoroughness, consider sharing things like: age, sex, medical condition(s), co-administered substances, infection type, reason for taking amoxicillin or Augmentin, length of treatment, administration frequency, etc.
• Did you have an undiagnosed allergy or hypersensitivity to amoxicillin or Augmentin?
• Why do you think it was the amoxicillin and not the condition it was treating (e.g. bacteria) that caused tinnitus or hearing changes?
• Did your hearing return to normal (pre-treatment baseline) after discontinuation of the medication?
• Did you stop treatment immediately after these symptoms emerged or did you continue taking it? (If you continued – how many additional days did you use the medication?)