Eflornithine adverse effects

Eflornithine (Vaniqa) is an irreversible inhibitor of ornithine decarboxylase, which catalyzes the rate-limiting step in the biosynthesis of polyamines. Polyamines are required for cell division and differentiation, and inhibition of ornithine decarboxylase affects the rate of hair growth. Topical eflornithine has been shown to be effective in reducing facial hair growth in approximately 30% of women when applied twice daily for 6 months of therapy. Hair growth was observed to return to pretreatment levels 8 weeks after discontinuation. Local adverse effects include stinging, burning, and folliculitis. 

In 42 patients with late-stage Trypanosoma brucei gam-biense trypanosomiasis, who relapsed after initial treatment with melarsoprol, a sequential combination of intravenous eflornithine (100 mg/kg every 6 hours for 4 days) followed by three daily injections of melarsoprol (3.6 mg/kg, up to 180 mg) was used (4). They were followed for 24 months. In one case the administration of eflornithine had to be interrupted for 48 hours because of convulsions, but treatment was then resumed without recurrence. Other adverse effects during treatment were abdominal pain or vomiting (n = 4 each), diarrhea (n = 1), and loss of hearing (n = 1). Two patients died during treatment ... 

The most frequent, serious, toxic effect of eflornithine is myelosuppression, which maybe unavoidable if successful treatment is to be completed decisions to modify dosage or to interrupt or cease treatment depend on the severity of the observed adverse event(s) and the availability of support facilities... 

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