Terbinafine
Pronunciation: (ter-BIN-uh-feen).
- Generic name
- terbinafine
- Brand names
- Terbinafine, Tamsil, Sebifin, Terbinex, Tergosil, Novo-Terbinafine
- Drug class
- Antifungal (Allylamine class)
Availability and supply rules vary by country
Trade names by country: United States · Canada
Australia: · Full directory
What terbinafine is and how it works
Uses, formulations, monitoring, and supply rules can differ by patient, product, and country. Follow the exact local product information and professional advice.
Mechanism of action: how terbinafine works
Terbinafine is an allylamine antifungal that inhibits the enzyme squalene epoxidase, a key component in the ergosterol biosynthesis pathway. This inhibition leads to decreased ergosterol production and accumulation of toxic squalene within fungal cells, resulting in increased cell membrane permeability and fungal cell death. Terbinafine is fungicidal against dermatophytes and some molds, and fungistatic against certain yeasts. (1) (2)
What terbinafine is used for
Onychomycosis (fungal nail infection) of the toenail or fingernail due to dermatophytes (tinea unguium); topical forms are used for tinea pedis, tinea cruris, and tinea corporis.
Oral terbinafine tablets are FDA-indicated for onychomycosis of the toenail or fingernail caused by dermatophytes (tinea unguium). Laboratory confirmation (KOH preparation, fungal culture, or nail biopsy) is recommended before starting treatment. (2)
Before taking terbinafine
Do not take / not appropriate for
- Contraindicated in patients with chronic or active liver disease and those with known hypersensitivity to terbinafine. (Contraindication) (2)
Tell your clinician about
(2)How to take terbinafine
- General Instructions: Take terbinafine exactly as prescribed by your healthcare provider. Do not take more or less than directed.. Adult Dosing: For fingernail onychomycosis: 250 mg orally once daily for 6 weeks. For toenail onychomycosis: 250 mg orally once daily for 12 weeks. For skin infections: topical application once or twice daily for 1–4 weeks depending on the condition.. Pediatric Dosing: Dosing in children is weight-based and should be determined by a pediatrician. Oral terbinafine is generally reserved for severe or extensive infections.. Administration: Oral tablets should be taken with or without food. Topical forms should be applied to clean, dry skin and hands washed after application.. When To Stop: Complete the full prescribed course of terbinafine, even if your symptoms improve early — do not end treatment without your prescriber's guidance. Seek medical attention promptly if you develop signs of liver problems or severe skin reactions; let the clinician you see advise on whether to continue or stop terbinafine.. Storage: Store at room temperature away from moisture, heat, and direct light. Keep out of reach of children.
- This page does not provide a dose calculator. Dosing must follow the prescriber, pharmacist, or product label.
Procedures and treatment changes
Tell the treating team before surgery, procedures, or any medicine change. Do not alter treatment without the responsible clinician. (2)
Missed dose
If you miss a dose, take it as soon as you remember. If it is almost time for your next dose, skip the missed dose and resume your regular schedule. Do not take an extra dose to catch up.
Overdose
In case of overdose, seek emergency medical attention or contact a poison control center immediately. Symptoms may include headache, nausea, stomach pain, dizziness, or rash. Supportive care is the mainstay of treatment. (2)
Side effects
Side effects and their urgency vary; report severe, persistent, or concerning symptoms to a healthcare professional.
Headache
Incidence: Common (12.9% vs 9.5% placebo in US/Canadian trials)
Gastrointestinal symptoms (diarrhea, dyspepsia, abdominal pain, nausea, flatulence)
Incidence: Common (diarrhea 5.6%, dyspepsia 4.3%, abdominal pain 2.4%, nausea 2.6% in trials)
Rash, pruritus, or urticaria
Incidence: Common (rash 5.6%, pruritus 2.8%, urticaria 1.1% in trials)
Taste or smell disturbance
Incidence: Reported (taste disturbance 2.8% in trials); can be prolonged or permanent
Liver enzyme abnormalities / signs of liver problems (yellowing of skin or eyes, dark urine, persistent nausea)
Incidence: Liver enzyme elevation ≥2x ULN reported in 3.3% of trial patients
Serious warnings
Serious liver injury has been reported — serious
Symptoms: Serious liver injury has been reported; monitor for signs of liver dysfunction. May cause severe skin reactions, including Stevens-Johnson syndrome. Taste disturbances (including loss of taste) may occur and can be prolonged. Use with caution in patients with renal impairment. Drug interactions with certain antidepressants, beta-blockers, and other medications.
Action: Follow the urgency stated and seek prompt or emergency care when indicated. (2)
Contraindications recorded in the clinician database — serious
Symptoms: Contraindications recorded in the clinician database: Contraindicated in patients with chronic or active liver disease and those with known hypersensitivity to terbinafine. Use with caution in patients with renal impairment (creatinine clearance <50 mL/min), pre-existing psoriasis or lupus (may exacerbate), and those taking drugs metabolized by CYP450 enzymes. Monitor for hepatic dysfunction and severe skin reactions.
Action: Follow the urgency stated and seek prompt or emergency care when indicated. (2)
Interactions
| Medicine or test | Effect | Action |
|---|---|---|
| Recorded interactions | Terbinafine may interact with several medications, including certain antidepressants (SSRIs, tricyclics), beta-blockers, cyclosporine, warfarin, and some antifungals. It can increase or decrease the levels of these drugs in your body. Always inform your healthcare provider of all medications and supplements you are taking. | (1) |
Pregnancy, breastfeeding, kidney/liver function, age
Pregnancy
The FDA label states that available postmarketing data on oral terbinafine in pregnant women are insufficient to evaluate drug-associated risk of major birth defects, miscarriage, or adverse maternal/fetal outcomes. Animal reproduction studies at doses well above the maximum recommended human dose showed no malformations or fetal harm. Use only if clearly needed, on a clinician's advice. (2)
Breastfeeding
The FDA label states that terbinafine is present in human milk after oral dosing, but there are no data on effects on the breastfed child or on milk production. The developmental and health benefits of breastfeeding should be weighed against the mother's clinical need for terbinafine and any potential effects on the infant — discuss with a healthcare provider. (2)
Children
Frequency: Not recommended for pediatric use.. Weight Based: Not established for pediatric use.. Max Daily Dose: Not recommended for pediatric use.. Max Single Dose: Not recommended for pediatric use.. Age Restrictions: Safety not established in children. (2)
Renal_impairment
Renal: the FDA label states that use in patients with renal impairment (creatinine clearance ≤50 mL/min) has not been adequately studied; no specific dose adjustment is given. Hepatic: oral terbinafine is contraindicated in chronic or active liver disease — liver failure, sometimes leading to transplant or death, has occurred in patients with and without pre-existing liver disease; obtain baseline and periodic liver function tests. (2)
Hepatic_impairment
Renal: the FDA label states that use in patients with renal impairment (creatinine clearance ≤50 mL/min) has not been adequately studied; no specific dose adjustment is given. Hepatic: oral terbinafine is contraindicated in chronic or active liver disease — liver failure, sometimes leading to transplant or death, has occurred in patients with and without pre-existing liver disease; obtain baseline and periodic liver function tests. (2)
Monitoring
(2)Storage
The FDA label directs that terbinafine tablets be stored at 20°C to 25°C (68°F to 77°F) (USP Controlled Room Temperature), in a tight container, protected from light. Keep out of reach of children.
Professional information
Clinician-facing context only. This section does not replace current product labeling.
General
Indication: Recorded indication
Dose summary: 250 mg orally once daily for 6 weeks for fingernail infections and 12 weeks for toenail infections.
Renal context: The FDA label states that in patients with renal impairment (creatinine clearance ≤50 mL/min), the use of oral terbinafine tablets has not been adequately studied. No specific adjusted dose is given; use in this population should be assessed by the prescriber. (1) (2)
Hepatic guidance
Oral terbinafine tablets are FDA-contraindicated in patients with chronic or active liver disease. Cases of liver failure, some leading to liver transplant or death, have occurred in individuals with and without pre-existing liver disease; the severity/outcome of hepatic events may be worse in patients with active or chronic liver disease. Obtain baseline serum transaminases before starting and monitor periodically during therapy; if signs of liver injury develop, the prescriber will decide whether treatment should be discontinued.
Frequently asked questions
How long does it take for terbinafine to work?
Improvement in skin infections is usually seen within a few days to weeks. For nail infections, visible improvement may take several months after completing therapy, as healthy nail growth replaces the infected nail.
Can I drink alcohol while taking terbinafine?
It is best to avoid alcohol while taking terbinafine, as both can affect the liver and increase the risk of liver damage.
What should I do if I develop yellowing of my skin or eyes?
Seek medical attention immediately. Yellowing of the skin or eyes may be a sign of serious liver problems; let the healthcare provider you contact advise on whether to continue or stop terbinafine.
Is terbinafine safe during pregnancy or breastfeeding?
Terbinafine should only be used during pregnancy if clearly needed and prescribed by a doctor. It is excreted in breast milk; breastfeeding is not recommended while taking oral terbinafine.
Can terbinafine be used for all types of fungal infections?
Terbinafine is effective against many dermatophyte (skin, hair, nail) infections but is not effective for all fungal infections, such as those caused by Candida or certain molds.
What are the signs of a serious allergic reaction to terbinafine?
Signs include rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, and trouble breathing. Seek emergency medical help if these occur.
Can children use terbinafine?
Terbinafine may be used in children for certain fungal infections, but dosing and safety should be determined by a pediatrician.
What happens if I take too much Terbinafine?
Taking too much Terbinafine can lead to an overdose, potentially causing symptoms such as headache, dizziness, nausea, vomiting, and abdominal pain. In severe cases, liver damage may occur. If you suspect an overdose, seek immediate emergency medical attention or contact a poison control center. Do not attempt to induce vomiting unless instructed by a medical professional.
Is Terbinafine safe during pregnancy?
Terbinafine is classified as Pregnancy Category B, meaning animal reproduction studies have shown no risk to the fetus, but there are no adequate and well-controlled studies in pregnant women. Therefore, it should only be used during pregnancy if clearly needed and the potential benefits outweigh the potential risks. Always consult your healthcare provider before taking any medication during pregnancy.
What is the mechanism of action of terbinafine?
Terbinafine is an allylamine antifungal that inhibits the enzyme squalene epoxidase, a key component in the ergosterol biosynthesis pathway. This inhibition leads to decreased ergosterol production and accumulation of toxic squalene within fungal cells, resulting in increased cell membrane permeability and fungal cell death. Terbinafine is fungicidal against dermatophytes and some molds, and fungistatic against certain yeasts. (1) (2)
What is the generic name of Terbinafine?
The generic name is terbinafine. It is sold under brand names including Terbinafine, Tamsil, Sebifin, Terbinex, Tergosil, Novo-Terbinafine.
What class of drug is terbinafine?
Terbinafine is classed as: Antifungal (Allylamine class).
References
- Terbinafine medicine record (clinician‑authored internal database)MedGuideGlobal · Not country‑specific · accessed 2026-08-07 · source 1
- Terbinafine Hydrochloride Tablet, USP — prescribing informationU.S. National Library of Medicine DailyMed (FDA label) · United States · accessed 2026-08-07 · source 2
- TERBINAFINE (TERBINAFINE HYDROCHLORIDE TABLET) TABLET [AMERISYN LLC] — US prescribing information (DailyMed SPL)U.S. National Library of Medicine (DailyMed) · US · accessed 2026-08-14 · source 3
- Terbinafine — FDA approval record (Drugs@FDA ANDA078297)U.S. Food and Drug Administration · US · accessed 2026-08-14 · source 4
- terbinafine — RxNorm normalized drug concept (RXCUI 235838)U.S. National Library of Medicine (RxNorm) · US · accessed 2026-08-14 · source 5
Brand names by country
Single-ingredient terbinafine names are shown separately by country. Product availability, strengths, and supply rules can change; combination products are not included here.
Priority countries
United States
- Athletes Foot1 g00g · h e b
- Lamisil AT1 g00g · karo healthcare inc.
- equate Athletes Foot1 g00g · wal-mart stores inc
- Silka Jock Itch1 g00g · genomma lab usa, inc.
- Toenail Fungus Treatment.01 g/mL · shenzhen wankelai e-commerce co., ltd.
- LAMISIL AT TERBINAFINE HYDROCHLORIDE1 g00g · voyant beauty, inc.
- Curist Antifungal Relief1 g00g · little pharma, inc.
- PHARMBANNER TINEA VERSICOLOR Cream1 g00g · shenzhen xinxin yunhai technology co., ltd.
- Athlete Foot Cream1 g00g · beautivity llc
- Silka Antifungal1 g00g · genomma lab usa, inc.
Canada
- LAMISIL
- LAMISIL CRM