Terbinafine Topical

Terbinafine is used to treat infections caused by a fungus. It works by killing the fungus or preventing its growth.

Terbinafine is applied to the skin to treat:

• ringworm of the body (tinea corporis);
• ringworm of the foot (interdigital and plantar tinea pedis; athlete's foot);
• ringworm of the groin (tinea cruris; jock itch);
• tinea versicolor (sometimes called “sun fungus”); and
• yeast infections of the skin (cutaneous candidiasis).

terbinafine is available both over-the-counter (OTC) and with your doctor's prescription.

• Terbinafine HCl
• Terbinafine Hydrochloride

Excipient information presented when available (limited, particularly for generics); consult specific product labeling. [DSC] = Discontinued product

Cream, External, as hydrochloride:

LamISIL AT: 1% (12 g, 24 g, 30 g, 36 g, 42 g) [contains benzyl alcohol, cetyl alcohol]

LamISIL AT Jock Itch: 1% (12 g) [contains benzyl alcohol, cetyl alcohol]

Generic: 1% (12 g [DSC], 15 g, 24 g [DSC], 30 g)

Gel, External:

LamISIL Advanced: 1% (12 g) [contains alcohol, usp]

Solution, External, as hydrochloride:

LamISIL AT Spray: 1% (30 mL [DSC], 125 mL) [contains alcohol, usp, propylene glycol]

LamISIL Spray: 1% (30 mL [DSC]) [contains alcohol, usp]

Synthetic allylamine derivative which inhibits squalene epoxidase, a key enzyme in sterol biosynthesis in fungi. This results in a deficiency in ergosterol within the fungal cell wall and results in fungal cell death.

Absorption

Limited (<5%)

Distribution

Distributed to sebum and skin predominantly

Half-Life Elimination

14 to 35 hours

There are no known significant interactions.

Concerns related to adverse events:

• Local irritation: If irritation/sensitivity develops, discontinue therapy and institute appropriate alternative therapy.

Dosage form specific issues:

• Benzyl alcohol and derivatives: Some dosage forms may contain benzyl alcohol; large amounts of benzyl alcohol (≥99 mg/kg/day) have been associated with a potentially fatal toxicity (“gasping syndrome”) in neonates; the “gasping syndrome” consists of metabolic acidosis, respiratory distress, gasping respirations, CNS dysfunction (including convulsions, intracranial hemorrhage), hypotension, and cardiovascular collapse (AAP ["Inactive" 1997]; CDC, 1982); some data suggests that benzoate displaces bilirubin from protein binding sites (Ahlfors, 2001); avoid or use dosage forms containing benzyl alcohol with caution in neonates. See manufacturer's labeling.

Other warnings/precautions:

• Appropriate use: For topical use only. Not intended for ophthalmologic, oral, or vaginal administration. Do not use on nails or scalp.

Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Stop using terbinafine and call your doctor at once if you have:

• severe blistering, itching, redness, peeling, dryness, or irritation of treated skin.

Less serious side effects may be more likely, and you may have none at all.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

It is not likely that other drugs you take orally or inject will have an effect on topically applied terbinafine. But many drugs can interact with each other. Tell each of your health care providers about all medicines you use, including prescription and over-the-counter medicines, vitamins, and herbal products.

Before using terbinafine, tell your doctor or pharmacist if you are allergic to it; or to other allylamine antifungals (e.g., naftifine); or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

If you have the following health problem, consult your doctor or pharmacist before using this product: athlete's foot on the bottom or side of the foot.

During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor.

Other forms of this medication pass into breast milk when taken by mouth. It is not known whether this drug passes into breast milk when applied to the skin. This drug should not be used on the breast while breast-feeding. Consult your doctor before breast-feeding.

Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.