Terbinafine hydrochloride, or simply terbinafine, is a medication used to treat fungal infections of the skin, fingernails and toenails. It is available as a liquid solution, cream or oral tablets. Side effects are generally mild and short lived but can be severe and life threatening.
Central Nervous System Side Effects
Terbinafine, like many drugs, may cause headache or fatigue. Alteration in taste is an unusual reaction that usually does not persist. However, there have been reports of weight loss due to decreased food intake as a result of the taste disturbance. A generalized sensation of not feeling well, called malaise, may be seen.
Gastrointestinal System Side Effects
Nausea, diarrhea, abdominal pain and upset stomach are known side effects of terbinafine. Cases of liver damage or failure leading to transplant or death, although rare, have been reported. The likelihood and severity of such reactions are increased in those with preexisting liver disease or generalized poor health. Monitoring of liver function through blood tests is recommended in those taking terbinafine.
Dermatological Side Effects
Skin rashes, varying in severity from mild to fatal, have occurred in those taking terbinafine. A potentially life threatening condition known as Stevens-Johnson syndrome is possible, but itching and hives are more common in patients on this drug. Rare cases of cutaneous or systemic lupus erythematosus have been reported and should be watched for. Hair loss has also been reported.
Hematological Side Effects
There have been reports of falling counts of certain types of white blood cells in people taking terbinafine. This could impair the immune response and leave patients at increased risk of infection. This concern is greater in those with previous immune system problems.
Musculoskeletal Side Effects
There have been rare reports of muscle and joint aches with terbinafine use.
Allergic Reaction
Severe allergic reactions characterized by swelling of the tongue and airway and a skin rash are rare, but possible. Such anaphylactic episodes may be life threatening.
Topical Terbinafine Side Effects
Terbinafine solution or cream carries less risk of serious side effects, as concentration of the drug in the blood is lower than when the medication is taken internally. Local site irritation, burning, itching and redness of the skin may occur. Rashes and skin peeling may also be seen.
