This grade answers one narrow question: how strong is the public evidence and safety record behind this drug, and how clean is its money trail and court record? It is not a verdict on whether the drug is right for you.
Listed on the WHO Model List of Essential Medicines: a global expert panel judged it among the medicines a health system should always have, on evidence of value, not marketing.
1. INDICATIONS AND USAGE Terbinafine tablets are indicated for the treatment of onychomycosis of the toenail or fingernail due to dermatophytes (tinea unguium). Prior to initiating treatment, appropriate nail specimens for laboratory testing [potassium hydroxide (KOH) preparation, fungal culture, or nail biopsy] should be obtained to confirm the diagnosis of onychomycosis. Terbinafine tablets are an allylamine antifungal indicated for the treatment of onychomycosis of the toenail or fingernail due to dermatophytes (tinea unguium). ( 1 )
4. CONTRAINDICATIONS Terbinafine tablets are contraindicated in patients with: • History of allergic reaction to oral terbinafine because of the risk of anaphylaxis [see Adverse Reactions (6.2) ] • Chronic or active liver disease [see Warnings and Precautions (5.1) ] • History of allergic reaction to oral terbinafine because of the risk of anaphylaxis. ( 4 ) • Chronic or active liver disease. ( 4 )
5. WARNINGS AND PRECAUTIONS • Liver failure, sometimes leading to liver transplant or death, has occurred with the use of oral terbinafine. Obtain pretreatment serum transaminases. Prior to initiating treatment and periodically during therapy, assess liver function tests. Discontinue Terbinafine tablets if liver injury develops. ( 5.1 ) • Taste disturbance, including taste loss, has been reported with the use of Terbinafine tablets. Taste disturbance can be severe, may be prolonged, or may be permanent. Discontinue Terbinafine tablets if taste disturbance occurs. ( 5.2 ) • Smell disturbance, including loss of smell, has been reported with the use of Terbinafine tablets. Smell disturbance may be prolonged, or may be permanent. Discontinue Terbinafine tablets if smell disturbance occurs. ( 5.3 ) • Depressive symptoms have been reported with terbinafine use. Prescribers should be alert to the development of depressive symptoms. ( 5.4 ) • Severe neutropenia has been reported. If the neutrophil count is less than or equal to 1000 cells/mm 3 , Terbinafine tablets should be discontinued. ( 5.5 ) • Stevens-Johnson syndrome, toxic epidermal necrolysis, erythema multiforme, exfoliative derma...
6. ADVERSE REACTIONS Common (greater than 2% of patients treated with Terbinafine tablets) reported adverse events include headache, diarrhea, rash, dyspepsia, liver enzyme abnormalities, pruritus, taste disturbance, nausea, abdominal pain, and flatulence. ( 6.1 ). To report SUSPECTED ADVERSE REACTIONS, contact Breckenridge Pharmaceutical, Inc. at 1-800-367-3395, or go to www.bpirx.com, or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. The most frequently reported adverse events observed in the 3 US/Canadian placebo-controlled trials are listed in the table below. The adverse events reported encompass gastrointestinal symptoms (including diarrhea, dyspepsia, and abdominal pain), liver test abnormalities, rashes, urticaria, pruritus, and taste disturbances. Changes in the ocular lens and retina have been reported following the use of Terbinafine tablets in controlled trials. The clinical significance o...
Dosage and Administration: Assessment Prior to Initiation ( 2.1 ) 8/2016 Contraindications ( 4 ) 8/2016 Warnings and Precautions: Hepatotoxicty ( 5.1 ) 8/2016 Warnings and Precautions: Thrombotic Microangiopathy ( 5.8 ) 1/2017
Source: FDA SPL label for Terbinafine Hydrochloride (Aphena Pharma Solutions - Tennessee, LLC), effective 20171215. Full label on DailyMed.
These are counts of reports people filed, not rates of harm. Anyone can file one, and nobody checks whether the drug was the cause. Millions of doses are taken for every report sent, so the useful part is how this drug compares with the average across all drugs.
| 2019 | 2020 | 2021 | 2022 | 2023 | 2024 | 2025 | 2026 |
|---|---|---|---|---|---|---|---|
| 1,195 | 1,140 | 888 | 773 | 838 | 843 | 855 | 365 |
2,553 reports blaming this drug for every million Medicare prescriptions filled, which is 0.9× the typical drug on this site. (2,040 reports in 2024–2026, against 799,100 Medicare fills in one year. This is the one number here that accounts for how many people take the drug.)
Source: the FDA's Adverse Event Reporting System (FAERS). Reports are voluntary and unverified. Drugs that are prescribed a lot, in the news, or in lawsuits attract more reports, so the percentages are compared with the whole database to correct for that partly, not fully.
Counts measure how much evidence exists and how transparent it is, not how big the benefit is. For that, ask your prescriber: if 100 people like me took this, how many would get better because of it, and how many would be harmed? (Doctors call these the "number needed to treat" and "number needed to harm.") It differs by condition and is the number drug ads leave out. Sources: PubMed, ClinicalTrials.gov.
In 2024, drug companies reported $0 in payments to US physicians and hospitals tied to this drug across 0 transactions.
No pending federal MDL names this drug or its brands.
Not named in any federal pharmaceutical settlement of $100M or more on record.
Sources: CMS Open Payments (Sunshine Act); Judicial Panel on Multidistrict Litigation pending docket list; DOJ settlements as tabulated on Wikipedia with links to the primary record. State-court and individual suits are not included.
Same ATC pharmacological class, graded ones first, best grade at the top. Being in the same class does not make them interchangeable for your condition; it makes them worth asking about.