What should you know about terbinafine and liver function?

Terbinafine is an antifungal medicine used in selected skin and nail infections. The liver processes oral terbinafine, and a medicine-related liver problem can occasionally develop during treatment. This is different from ordinary stomach upset and should be assessed rather than self-managed.

Tell the prescriber about previous liver disease, heavy alcohol use, other medicines, supplements and any earlier reaction to antifungal treatment. A clinician may decide whether liver blood tests are appropriate before or during an oral course. The decision depends on your health, the infection being treated and the formulation prescribed.

Take terbinafine only as directed and do not share tablets. Keep a list of prescription medicines, over-the-counter products and supplements, because combinations can affect prescribing decisions. Do not start a new supplement or alter the dose without checking with the prescriber or pharmacist.

For more context about the medicine, see [Terbinafine](/materials/terbinafine/) and [Oral Antifungal Treatment](/treatments/medical-dermatology/oral-antifungal-therapy/). If monitoring was requested, arrange it on the advised schedule even when the skin or nail appears to be improving.

Contact the prescribing clinician promptly if you develop persistent nausea, loss of appetite, unusual tiredness, pain in the upper abdomen, dark urine, pale stools or yellowing of the skin or eyes. These symptoms can have other causes, but they warrant medical review while taking terbinafine.

Seek urgent help for severe illness, confusion, fainting, trouble breathing or swelling of the face or throat. Do not take another dose until you have received personalised advice if a clinician tells you to stop or suspects a serious reaction.

Ask whether your liver history or current medicines change the suitability of terbinafine, whether testing is needed, which symptoms should trigger a call, and what to do if a dose is missed or a test is abnormal.