Two new drugs for nail fungal infections - Lamisil, Sporanox

Healthfacts, Sept, 1996

A heavily advertised, new oral drug for nail fungus has generated interest recently because this infection is notoriously resistant to topical treatment. What's more, fungal nail disease does not resolve spontaneously.

Lamisil (generic name: terbinafine), available for topical use since 1993, has just been approved as an oral drug. Though comparable in efficacy to another new oral antifungal drug, Sporanox, Lamisil has the potential for fewer adverse interactions with other commonly prescribed drugs.

Finger- and toenails can be affected by a type of fungus that invades dead tissue of the skin or its appendages, such as the nails and hair. Toenail fungal infections, the most common site, often develop in people with a long-standing case of athlete's foot. For most people, it is a cosmetic prob- lem, causing an unsightly thickening of the nails. One type of fungal infec- tion (Fulsarium) could become lethal, however, in people whose immune systems are compromised with illness, such as AIDS, or by a treatment, such as cancer chemotherapy.

The two new drugs must be taken for 12 weeks and are quite expensive. Sporanox costs $941 for the 12-week treatment course, and Lamisil costs $473. Lamisil was compared with Sporanox and judged the better, albeit qualified, choice in a recent issue of The Medical Letter (16 August 1996), a physicians' publica- tion with no drug company advertising. Both drugs have comparable efficacy, but doctors were warned away from prescribing Sporanox because it may interact and cause serious toxicity when taken with other drugs like Halcion, Seldane, Hismanal, or Propulsid.

How effective is the safer choice? In the ads directed to physicians, Lamisil's manufacturer, Sandoz, claims a 70% cure rate at 12 weeks for toenail fungus; and a 79% cure rate at six weeks for fingernail fungus. But The Medi- cal Letter expressed reservations: The advisability of taking either of these expensive drugs for months to treat an infection that is mainly cosmetic and may relapse is unclear.

The British Medical Journal advises doctors to take a specimen from the infected nail in order to confirm the diagnosis (11 November 1995). There are several types of fungal infection, and many people have been inappropriately treated because they have not received the correct diagnosis .