Generic Name: Terbinafine hydrochloride

Brand Names: Lamisil, Onmel, Terbisil

Lamisil is an antifungal medication that prevents fungus from growing on the skin. Lamisil is used to treat infections caused by a fungus that affects the fingernails or toenails. Lamisil may also be used for purposes not listed in this medication guide. You should not use Lamisil if you are allergic to terbinafine, or if you have:

  • liver disease;
  • a history of Long QT syndrome; or
  • if you are pregnant or breastfeeding.

Do not take Lamisil if you are taking cisapride (Propulsid).

Taking these medications together can cause very serious heart problems.

To make sure Lamisil is safe for you, tell your doctor if you have ever had:

liver disease (especially cirrhosis);

a heart rhythm disorder; or

Long QT syndrome (in you or a family member).

Some people taking terbinafine have developed severe liver damage leading to liver transplants or death. Call your doctor at once if you have nausea, upper stomach pain that may spread to your right shoulder, itching, loss of appetite, dark urine, clay-colored stools, or jaundice (yellowing of your skin or eyes).

Lamisil is not expected to harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant during treatment.

How should I take Lamisil?

Take Lamisil exactly as prescribed by your doctor. Follow all directions on your prescription label and read all medication guides or instruction sheets. Use the medicine exactly as directed.

Your doctor may occasionally change your dose to make sure you get the best results.

Do not take this medicine in larger or smaller amounts or for longer than recommended.

Take Lamisil with food.

Shake the oral suspension (liquid) well just before you measure a dose. Measure liquid medicine with the dosing syringe provided, or with a special dose-measuring spoon or medicine cup. If you do not have a dose-measuring device, ask your pharmacist for one.

Call your doctor if your nail fungus does not seem to be getting better after 4 weeks of treatment, or if it seems to be getting worse.


Terbinafine is rapidly and almost completely absorbed following oral administration. The mean bioavailability of an 250 mg tablet is greater than 65%. Food decreases the extent of and slightly delays the absorption of terbinafine, but does not alter its bioavailability. Following a single 250 mg oral dose of terbinafine to fasting subjects, peak plasma concentrations (Cmax) occur between 6 and 12 hours (Tmax). The elimination half-life in plasma is approximately 30 hours. Terbinafine is metabolized in the liver by oxidative N-dealkylation to 4′-hydroxyterbinafine and further metabolism through side chain oxidation and glucuronide conjugation. Less than 10% of parent drug is excreted unchanged in the urine.

Indications and Usage for Lamisil

Lamisil Tablets are indicated for the treatment of onychomycosis of the toenail or fingernail due to dermatophytes (tinea unguium).

Limitations of Use:

Lamisil is not effective in the treatment of pityriasis versicolor.

Lamisil should not be used in patients with chronic or active liver disease.

Side Effects

Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat. Stop taking Lamisil and call your doctor at once if you have:

  • severe stomach pain, diarrhea that is watery or bloody;
  • jaundice (yellowing of the skin or eyes);
  • pale stools, dark urine;
  • cough, wheezing, chest pain, trouble breathing;
  • headache with chest pain and severe dizziness, fainting, fast or pounding heartbeats; or
  • sudden numbness or weakness (especially on one side of the body), problems with vision or speech.

This is not a complete list of side effects and others may occur.

Dosage and Administration

The recommended adult dose of Lamisil Tablets is 250 mg (one tablet) once daily for 6 weeks. In some patients, a complete cure may take longer.

Lamisil should be taken with or without food.

Toenail Onychomycosis: The recommended adult dose of Lamisil Tablets is 250 mg (one tablet) once daily for 12 weeks. In some patients, complete cure may take longer.

Fingernail Onychomycosis: The recommended adult dose of Lamisil Tablets is 250 mg (one tablet) once daily for 6 weeks. In some patients, complete cure may take longer.

For the treatment of onychomycosis, Lamisil Tablets should be administered until a cure is achieved or there is evidence of persistent or recurrent infection.

How Supplied/Storage and Handling

Lamisil (terbinafine hydrochloride) Tablets USP, 250 mg are white to yellow-tinged white, capsule shaped, biconvex, film-coated tablets debossed ‘D’ on one side and ‘5811’ on the other side containing terbinafine hydrochloride equivalent to 250 mg of terbinafine. They are supplied as follows:

Bottles of 100 NDC 59762-581-10

Bottles of 500 NDC 59762-581-50

Patient Counseling Information

  • Advise the patient to read the FDA-approved patient labeling (Patient Information).
  • Advise patients that Lamisil is usually taken for 6 to 12 weeks depending on the condition being treated.
  • Advise patients that they should take Lamisil Tablets with or without food.
  • Inform patients that some side effects may occur during


There is no specific antidote for terbinafine overdosage. If an overdose occurs, the patient should be treated symptomatically and supportive measures instituted as required. There is no evidence that hemodialysis or peritoneal dialysis enhances terbinafine elimination.

Contact Poison Control for up-to-date information on the management of Lamisil overdose


Store at 20° to 25°C (68° to 77°F) see USP Controlled Room Temperature.