Toenails and agranulocytosis.

The objective of this article was the study of 12 cases of granulocytopenia associated with terbinafine use in Australia, the most recent, with agranulocytosis, which is described in detail. The mean age of the participants was 64 years (range 35-79 years). Sex was reported in 11 patients and all but one was a woman. Time to onset of neutropenia/agranulocytosis was 4-5 weeks in most cases. Neutropenia was typically severe with neutrophil counts < or = 0.3 x 10(3)/mm3 in all but 3 of 11 patients where counts were given. Terbinafine was stopped in all patients, five were hospitalized and one died of septic shock. Six patients received antibiotics and three were given granulocyte colony stimulating factor. Terbinafine, indicated for the treatment of onychomycosis and ringworm, may rarely be associated with granulocytopenia, which is typically severe. It takes approximately 1 month or longer for the development of manifestations of neutropenia, which include fatigue, fever, sore throat and mouth ulceration. Withdrawal of terbinafine and appropriate management of febrile neutropenia will probably result in a favourable outcome. Patients should be warned about this potentially life-threatening adverse reaction and the warning symptoms.