Drug Name

Lamisil (Terbinafine)

Drug Uses

Tablets: Fungal infections of the toe, or fingernail, caused by the fungus, tinea unguium. Cream: Fungal infections of the skin, including tinea pedis ("athlete's foot"), tinea corporis, and tinea cruris ("jock itch").

How Taken

Tablets: The usual dose is 250 mg once daily for 6 weeks for the treatment of fingernails, and 12 weeks for the treatment of toenails. Alternatively, terbinafine may be given as two tablets (500 mg) once daily for 7 days during the first week of each month for 3 months for toenail infections. For children under 20kg (44 pounds), a dose of 62.5 mg/day, and for children between 20 and 40kg (44 and 88 pounds) a dose of 125 mg/day have been recommended. Lamisil may be taken with or without food.

Drug Class and Mechanism

Lamisil is an antifungal agent that is taken by mouth or applied to the skin. Lamisil acts by interfering with the ability of fungi to make chemicals, called sterols, that are an important part of the membrane that surrounds fungal cells and holds them together. This weakens the cell membrane. Oral Lamisil is more effective for treating fungal nail infections than griseofulvin (Fulvicin; Gris-Peg) and itraconazole (Sporanox), two other antifungal agents, used for treating fungal nail infections. Topical Lamisil was approved by the FDA in 1993. Lamisil oral tablets were approved in 1996.

Missed Dose

If you miss a dose, take it as soon as you remember. If it is near the time of the next dose, skip the missed dose and resume your usual dosing schedule. Do not double the dose to catch up.

Storage

Store at room temperature 77 degrees F (25 degrees C) away from light and moisture. Do not store in the bathroom. Keep all medicines away from children and pets.

Warnings/Precautions

Before taking Lamisil, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. Before using this medication, tell your doctor or pharmacist your medical history, especially of: immune system problems, kidney disease, liver disease, lupus erythematosus. Limit alcoholic beverages. Daily use of alcohol may increase your chance for serious side effects. This medication should be used only when clearly needed during pregnancy. Fungal nail infection treatment usually may be postponed until after delivery. Discuss the risks and benefits with your doctor. This medication passes into breast milk and may have undesirable effects on a nursing infant. Therefore, breast-feeding is not recommended while using this drug. Consult your doctor before breast-feeding.

Possible Side Effects

Diarrhea, stomach upset, temporary change or loss of taste, or tiredness may occur. If any of these effects persist or worsen, notify your doctor or pharmacist promptly. Remember that your doctor has prescribed this medication because the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects. Tell your doctor immediately if any of these rare but very serious side effects occur: new signs of infection (e.g., fever, chills, persistent sore throat), easy bruising/bleeding, vision changes. This drug rarely has caused very serious (possibly fatal) liver disease. Tell your doctor immediately if you develop symptoms of liver disease, including: persistent nausea, loss of appetite, severe stomach/abdominal pain, dark urine, vomiting, yellowing of eyes or skin. A very serious allergic reaction to this drug is unlikely, but seek immediate medical attention if it occurs. Symptoms of a serious allergic reaction may include: rash, itching, swelling, severe dizziness, trouble breathing. If you notice other effects not listed above, contact your doctor or pharmacist.

More Information

Do not share this medication with others. This medication has been prescribed for your current condition only. Do not use it later for another infection unless told to do so by your doctor. A different medication may be necessary in those cases. Laboratory and/or medical tests (e.g., complete blood counts, liver function tests) should be performed periodically to monitor your progress or check for side effects. Consult your doctor for more details.