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Antifungal (allylamine)

Terbinafine: uses, side effects & precautions

Also known as Lamisil, Terbinafine.

This information is for general guidance only and does not constitute medical advice. Always consult a qualified healthcare professional for personal medical concerns. In an emergency, call your local emergency number.

What it is used for

  • Fungal nail infections (onychomycosis)
  • Athlete's foot (tinea pedis)
  • Ringworm of the body and groin (jock itch)
  • Other dermatophyte skin infections

How it works

Terbinafine blocks an early step in the way fungi build their cell membranes, causing a toxic substance to build up inside the fungal cell and killing it. It is particularly effective against the dermatophyte fungi that cause skin and nail infections.

How it is taken

Available as tablets for nail and stubborn infections and as a cream, gel, or spray for skin infections; some topical forms are sold over the counter. Apply or take it exactly as your doctor, pharmacist, or label directs. Tablet courses for nails can last several weeks to months, and topical treatments should be used for the full recommended time even if the skin looks better.

No doses here on purpose. The right strength and schedule depend on you — only a doctor or pharmacist should set them. Always follow your prescription and the label.

Common side effects

  • Stomach upset, nausea, or diarrhoea (tablets)
  • Headache
  • Rash
  • Changes in taste or temporary loss of taste (tablets)
  • Skin irritation at the application site (topical)

Serious effects — get help

  • Signs of liver problems (yellow skin or eyes, dark urine, persistent nausea, severe tiredness)
  • Severe skin reactions with blistering or peeling
  • Persistent loss of taste or appetite leading to weight loss
  • Severe allergic reaction
  • Symptoms of depression

If a reaction is severe — for example trouble breathing, swelling of the face or throat, or collapse — go to the nearest emergency room now or call your local emergency number. Do not wait for an online consultation.

Interactions to watch

  • Some antidepressants and beta-blockers processed by a particular liver enzyme
  • Other medicines metabolised by the liver
  • Tell your clinician about all your medicines before starting tablets

Who should take care

  • Tell your doctor about liver or kidney problems; liver monitoring may be advised for tablets
  • Report any persistent taste changes or stomach symptoms
  • Use in pregnancy or breastfeeding only on clinical advice
  • Mention any previous antifungal allergy

Frequently asked questions

How long before my nail looks normal again?
Even after a successful course, it takes months for a healthy nail to grow out and replace the damaged one. Be patient and complete the treatment as directed.
Will my sense of taste come back?
Taste changes from the tablets usually recover after stopping, though it can take weeks. Tell your doctor if taste loss is severe or persistent.
Do I need blood tests on the tablets?
Your clinician may check your liver function before or during a tablet course, especially for longer treatment. Follow their monitoring advice.
Is the cream as good as the tablets?
Cream is effective for skin infections like athlete's foot, while tablets are usually needed for nail infections. Your clinician will advise which suits your case.
Is Terbinafine safe to take?
For most people it is safe when taken exactly as a doctor or pharmacist advises and as printed on the label. Tell your clinician about your other medicines and health conditions, and seek urgent care for any serious reaction.

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