Medications and Drugs
GENERIC NAME: terbinafine
BRAND NAME: Lamisil
DRUG CLASS AND MECHANISM: Terbinafine is an antifungal
agent
that is taken by mouth or applied to the skin. Terbinafine 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
terbinafine 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
terbinafine was
approved by the FDA in 1993. Terbinafine oral tablets were
approved in
1996.
PRESCRIPTION: yes
GENERIC AVAILABLE: yes
PREPARATIONS: Tablets containing 250mg. Cream
containing 1%
terbinafine, 15gm and 30gm size tubes.
STORAGE: The tablets and the cream should be kept at
room
temperature, 15-30°C (59-86°F).
PRESCRIBED FOR: 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").
DOSING: Tablets: The usual dose is 250 mg once daily
for 6
weeks for treatment of the fingernails, and 12 weeks for
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. Terbinafine may be taken with
or without
food.
Cream: The cream is rubbed gently into the affected area (s).
The cream
usually is applied twice daily for 1 to 4 weeks.
DRUG INTERACTIONS: Rifampin reduces terbinafine blood
concentrations, potentially reducing the efficacy of
terbinafine, and
cimetidine (Tagamet) may increase terbinafine blood levels. The
latter
effect would not be expected to lead to problems.
PREGNANCY: Studies in animals using large dosages of
terbinafine
have not demonstrated toxic effects on the fetus; however,
there have not
been conclusive studies in humans. Since fungal infections of
the skin and
nails usually are not a serious problem, the manufacturer of
terbinafine
does not recommend therapy during pregnancy.
NURSING MOTHERS: There is no
data on the use of terbinafine during breast-feeding. Nursing mothers should
avoid using terbinafine on the breast or taking the drug orally.
SIDE EFFECTS: Terbinafine is a very safe medication.
The need to
discontinue therapy because of side effects is quite rare. The
most
frequently reported side effects are diarrhea, and abdominal
pain.
Increases in liver enzymes, hives, itching and altered taste
sensation
also have been observed.
Reference: FDA Prescribing Information
Last Editorial Review: 7/23/1998
Report Problems to the Food and Drug Administration
You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.
- Drug Interactions - Learn about potential drug interactions you may be exposed to. Drug interactions can occur with prescription drugs, OTC medication, vitamins, herbs, and supplements.
- Athlete's Foot - Get the facts on athlete's foot causes, symptoms, treatment, transmission and prevention. Vinegar and over-the-counter remedies may be used to treat foot fungus.
- Drugs: What You Should Know About Your Drugs - Find out what you should know about your drugs such as side effects, warnings and precautions, storage information, and if a generic version is as good as the brand name.
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