Terbinafine

Terbinafine is an allylamine antifungal [see ] .

• 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.ICD-10: B35.1

• Terbinafine tablets are contraindicated in patients with: • Chronic or active liver disease [see ] • History of allergic reaction to oral terbinafine because of the risk of anaphylaxis [see ] • Chronic or active liver disease. (4) • History of allergic reaction to oral terbinafine because of the risk of anaphylaxis.contraindicated

• Prior to administering, evaluate patients for evidence of chronic or active liver disease. • Fingernail onychomycosis: One tablet, once daily for 6 weeks. • Toenail onychomycosis: One tablet, once daily for 12 weeks. 2.1 Assessment Prior to Initiation Before administering terbinafine tablets, evaluate patients for evidence of chronic or active liver disease [see Contraindications (4) and ]. 2.2 Dosage Fingernail onychomycosis: One 250 mg tablet once daily for 6 weeks. Toenail onychomycosis: One 250 mg tablet once daily for 12 weeks. The optimal clinical effect is seen some months after mycological cure and cessation of treatment. This is related to the period required for outgrowth of healthy nail.

• 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. • 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. • 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. • Depressive symptoms have been reported with terbinafine use. Prescribers should be alert to the development of depressive symptoms. • Severe neutropenia has been reported. If the neutrophil count is less than or equal to 1000 cells/mm 3 , terbinafine tablets should be discontinued. • Stevens-Johnson syndrome, toxic epidermal necrolysis, erythema multiforme, exfoliative dermatitis, bullous dermatitis, and drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome have been reported with oral terbinafine use. If signs or symptoms of drug reaction occur, treatment with terbinafine tablets should be discontinued. 5.1 Hepatotoxicity Terbinafine tablets are contraindicated for patients with chronic or active liver disease.

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. To report SUSPECTED ADVERSE REACTIONS, contact Aurobindo Pharma USA, Inc. at 1-866-850-2876 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 U.S./Canadian placebo-controlled trials are listed in the Table 1. 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 of these changes is unknown. In general, the adverse events were mild, transient, and did not lead to discontinuation from study participation. Table 1.

8.1 Pregnancy Risk Summary Available data from postmarketing cases on the use of terbinafine tablets in pregnant women are insufficient to evaluate a drug-associated risk of major birth defects, miscarriage, or adverse maternal or fetal outcomes. In animal reproduction studies, terbinafine did not cause malformations or any harm to the fetus when administered to pregnant rabbits and rats during the period of organogenesis at oral doses up to 12 and 23 times the maximum recommended human dose (MRHD) of 250 mg/day, respectively (see data) . All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. The background risk of major birth defects and miscarriage for the indicated population is unknown; however, in the U.S. general population, the estimated background risk of major birth defects is 2% to 4% and of miscarriage is 15% to 20% of clinically recognized pregnancies. Data Animal Data In embryo-fetal development studies in rats and rabbits, pregnant animals received orally (by gavage) doses of terbinafine up to 300 mg/kg/day, during the period of organogenesis. There were no maternal or embryo-fetal effects in either species up to the maximum dose tested. The 300 mg/kg/day dose level in rats and rabbits corresponds to 23 and 12 times the MRHD [based on body surface area (BSA) comparisons], respectively.

Metabolism

Following oral administration, terbinafine is well absorbed (greater than 70%) and the bioavailability of terbinafine tablets as a result of first-pass metabolism is approximately 40%. Peak plasma concentrations of 1 mcg/mL appear within 2 hours after a single 250 mg dose; the AUC is approximately 4.56 mcg•h/mL.

Clinical experience regarding overdose with oral terbinafine is limited. Doses up to 5 grams (20 times the therapeutic daily dose) have been taken without inducing serious adverse reactions. The symptoms of overdose included nausea, vomiting, abdominal pain, dizziness, rash, frequent urination, and headache.

• Mar 9, 1999NDANDA020980Karo Hlthcare
• Mar 17, 2000NDANDA021124Karo Hlthcare
• Jul 2, 2007ANDAANDA078163Orbion Pharms
• Jul 2, 2007ANDAANDA078199Chartwell
• Jul 2, 2007ANDAANDA078297Aurobindo Pharma
• Jul 2, 2007ANDAANDA077137Cipla
• Jul 2, 2007ANDAANDA077511Sun Pharma Canada
• Jul 2, 2007ANDAANDA077533Invagen Pharms

1. 1Drug Ineffective8049.3%
2. 2Rash4845.6%
3. 3Pruritus4084.7%
4. 4Fatigue3834.4%
5. 5Nausea3754.3%
6. 6Pain3413.9%
7. 7Off Label Use3283.8%
8. 8Ageusia3223.7%
9. 9Headache2963.4%
10. 10Diarrhoea2863.3%
11. 11Dyspnoea2633.0%
12. 12Drug Interaction2573.0%
13. 13Malaise2552.9%
14. 14Anxiety2472.9%
15. 15Dizziness2372.7%

Recent PubMed references pinned to Terbinafine as a MeSH major topic. Citations link to pubmed.ncbi.nlm.nih.gov.

• Genetic confirmation of terbinafine resistance in Trichophyton rubrum mediated by the squalene epoxidase Leu393Phe mutation via targeted gene replacement.
  Medical mycology · 2026 · Suzuki S, Ishii M, Ohata S, et al.
  PMID 42096519DOI 10.1093/mmy/myag044
• Molecular Characterization and Preliminary NGS Profiling of Terbinafine-Resistant Trichophyton indotineae Isolates in Italy.
  Pathogens (Basel, Switzerland) · 2026 · Cruciani D, Papini M, Pisano L, et al.
  PMID 42075762DOI 10.3390/pathogens15040435
• Systemic use of terbinafine in veterinary medicine: A review of pharmacokinetic studies.
  Veterinary research communications · 2026 · Harvill L, Cox S
  PMID 42053962DOI 10.1007/s11259-026-11232-1
• First report of terbinafine resistance in human dermatophytosis in Uruguay.
  Medical mycology · 2026 · Puime CA, Bórmida V, Rosas M, et al.
  PMID 42024427DOI 10.1093/mmy/myag039
• Enhanced topical delivery of terbinafine HCl nanomicelles embedded in chitosan gel for improved antifungal activity.
  Drug development and industrial pharmacy · 2026 · Maryam GE, Nasir F, Gohar S, et al.
  PMID 41944045DOI 10.1080/03639045.2026.2654741
• The first reported case of terbinafine-resistant Trichophyton rubrum in Tunisia and its clinical implications.
  Journal de mycologie medicale · 2026 · Krima H, Korbi M, Belgacem S, et al.
  PMID 41916248DOI 10.1016/j.mycmed.2026.101621
• Targeting Mitochondrial Stress Responses: Terbinafine and Miglustat as Novel Lifespan and Healthspan Modulators.
  Aging cell · 2026 · Lalou A, Daskalaki I, Gkikas I, et al.
  PMID 41913053DOI 10.1111/acel.70452
• Cytochrome b5-Like Protein VdPBP1 Mediates Electron Transfer in Ergosterol Pathway to Confer Terbinafine Resistance of Verticillium dahliae.
  Journal of agricultural and food chemistry · 2026 · Li H, Zhang CN, Wang YH, et al.
  PMID 41875348DOI 10.1021/acs.jafc.5c17070

The 10 most recently updated of 58 ClinicalTrials.gov registrations naming Terbinafine as an intervention. Registration is not evidence of efficacy or safety — reference crosswalk only.

• Terbinafine for Biochemically Recurrent Prostate Cancer (TerbinaPro)
  Recruiting · Phase 2 · Interventional · 42 enrolled · Swiss Cancer Institute
  NCT07365423updated 2026-04-02
• A Phase 2 Study to Assess the Effectiveness of Topical Terbinafine in Participants With Mild to Moderate Onychomycosis of the Toenails
  Not yet recruiting · Phase 2 · Interventional · 200 enrolled · Onyx Axiom
  NCT07382427updated 2026-02-04
• Efficacy Comparison of Itraconazole Pulse Therapy and Terbinafine Therapy in Treatment of Tinea Capitis in Children.
  Completed · Interventional · 164 enrolled · Muhammad Aamir Latif
  NCT07068256updated 2025-11-28
• Efficacy of Ultraviolet B Phototherapy in the Management of Resistant and Relapsing Tinea Corporis and Tinea Cruris
  Not yet recruiting · Interventional · 36 enrolled · Cairo University
  NCT07242703updated 2025-11-21
• Terbinafine Hydrochloride for the Treatment of Otomycosis
  Not yet recruiting · Interventional · 50 enrolled · Assiut University
  NCT07152327updated 2025-10-01
• Clinical Effect of Caffeine Consumption in Patients Taking Oral Terbinafine
  Enrolling by invitation · Interventional · 52 enrolled · Weill Medical College of Cornell University
  NCT05667246updated 2025-10-01
• Population Pharmacokinetics of Terbinafine in Children With Tinea Capitis
  Recruiting · Observational · 60 enrolled · Shandong University
  NCT07046988updated 2025-07-02
• From Fungus to Virus, Investigating the Safety and Efficacy of Terbinafine in Chronic Hepatitis B Patients
  Recruiting · Phase 1 · Phase 2 · Interventional · 36 enrolled · Academisch Medisch Centrum - Universiteit van Amsterdam (AMC-UvA)
  NCT06295328updated 2025-02-07
• Terbinafine HCl 250 mg Tablet Under Fasting Conditions
  Completed · Phase 1 · Interventional · 28 enrolled · Teva Pharmaceuticals USA
  NCT00833586updated 2024-08-19
• A Vehicle-controlled Study of Topical MOB015B in the Treatment of Distal Subungual Onychomycosis (DSO)
  Active not recruiting · Phase 3 · Interventional · 350 enrolled · Moberg Pharma AB
  NCT05279846updated 2024-06-26

CPIC-curated drug–gene pairs for Terbinafine. Levels describe the strength of curated evidence and guideline status — never a recommendation to test or to adjust therapy.

• CYP2D6CPIC C (provisional)

Frequently asked questions

How does Terbinafine work?

Terbinafine is an allylamine antifungal [see ] .

What is Terbinafine used for?

According to FDA labeling, Terbinafine carries indications including: 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.. This is a reference summary of labeled uses, not medical advice or a treatment recommendation.

What class of drug is Terbinafine?

Terbinafine is classified as Antifungals for systemic use, Other antifungals for topical use, Allylamine Antifungal, Ergosterol Synthesis Inhibitors, Decreased Cell Wall Integrity.

What are the brand names for Terbinafine?

Terbinafine is marketed under brand names including Duotic, Klentz, Lamisil, Osurnia, Silka Cream, Simplera.

What are the contraindications for Terbinafine?

Terbinafine labeling lists contraindications including: Terbinafine tablets are contraindicated in patients with: • Chronic or active liver disease [see ] • History of allergic reaction to oral terbinafine because of the risk of anaphylaxis [see ] • Chronic or active liver disease. (4) • History of allergic reaction to oral terbinafine because of the risk of anaphylaxis.. Always consult the full prescribing information and a clinician.