Using Oral Terbinafine (LAMISIL) for Fungal Infections Poses Risks to Your Health

Serious health complications involving toxicity to the bone marrow have been reported in association with the drug terbinafine (LAMISIL), according to the August 2006 edition of the Australian Adverse Drug Reactions Bulletin. This is in addition to the hundreds of cases of liver toxicity that were the cause of our listing this drug as Do Not Use.

A healthy 60-year-old woman started taking terbinafine to treat a fungal infection in her big toenail and developed mouth ulcers, fever and muscle pain after about four weeks of using the drug.

Hospital doctors determined that she had an abnormally low white blood cell count and a neutrophil count of zero. (Neutrophils are a type of white blood cell that are especially protective against bacterial and fungal infections.) She recovered after treatment with intravenous antibiotics and a drug used to stimulate the production of white blood cells.

Doctors determined that the woman’s health complications were linked to her use of oral terbinafine, which is widely used to treat fungal infections in fingernails and toenails. While the fungal infection the woman was treating was largely a cosmetic concern, the drug she used created life-threatening medical conditions.

The Australian Adverse Drug Reactions Bulletin cited this woman’s experience with oral terbinafine to illustrate the kinds of reactions reported to Australia’s drug regulatory authority. The Australian agency received 663 accounts of adverse event involving oral terbinafine. The bulletin also reported that 16 of these reports linked oral terbinafine to a potentially life-threatening abnormal production of blood cells called blood dyscrasia. This type of adverse reaction has not been reported with the topical cream, gel or solution forms of terbinafine.

The 16 reports linking oral terbinafine to blood dyscrasias involved seven cases of a condition in which there is an insufficient number of white blood cells; seven reports in which a decrease in neutrophils was noted; and two cases in which there was an abnormal reduction in the number of red blood cells, white blood cells and blood platelets.

The decrease of any of these blood-cell counts is dangerous. White blood cells are very important in the body’s ability to fight off infections, making reductions in white blood cells dangerous because the chance of infection in patients increases.

Australian authorities said the health complications associated with the use of terbinafine occurred about four to six weeks after patients began to take the medication. The majority of these patients with decreased blood counts developed signs of infection.

Fortunately, patients who stopped using terbinafine and received appropriate treatment usually recovered rapidly, according to the Australian bulletin. Recovery was documented in 11 of the 16 reports, although in one case a 79-year-old woman experienced a severe decrease in the amount of white blood cells (agranulocytosis) about two months after starting terbinafine and died from septic shock despite treatment.

Public Citizen again warns against use of terbinafine

The Food and Drug Administration approved oral terbinafine in May 1996 for use in the United States to treat fungal infections of the toenail or fingernail. More than 2.1 million prescriptions were dispensed in U.S. pharmacies in 2005 alone. LAMISIL is produced by Novartis Pharmaceuticals of East Hanover, N.J.

Public Citizen’s Health Research Group listed terbinafine and itraconazole (SPORANOX), another drug used to treat fungal infections in nails, as “Do Not Use” drugs in our book Worst Pills, Best Pills in February 1999 because toenail fungus is a cosmetic condition and these drugs have been associated with large numbers of cases of liver failure.

In addition, the editors of The Medical Letter on Drugs and Therapeutics, a highly respected independent source of drug information for doctors and pharmacists, said in an August 16, 1996, review of these drugs that:

The advisability of taking either of these expensive drugs [itraconazole or terbinafine] for months to treat an infection that is mainly cosmetic and may relapse is unclear.

What You Can Do

You should not use terbinafine for cosmetic purposes, such as treating fungal infections in toenails.

If you have been taking terbinafine for longer than a month, be alert for any symptoms of possible infection such as fever, sore throat or mouth ulcers. If these symptoms develop, seek medical attention immediately.