Compassionate use of tecovirimat is well tolerated for the treatment of monkeypox, according to a research letter published online Aug. 22 in the Journal of the American Medical Association .

Angel N. Desai, M.D., M.P.H., from the University of California Davis Medical Center in Sacramento, and colleagues examined adverse events and clinical resolution of systemic symptoms and lesions in an uncontrolled cohort study of 25 patients with laboratory-confirmed monkeypox, who were treated with tecovirimat on a compassionate use basis. Nine of the patients had HIV, one had received the smallpox vaccine more than 25 years earlier, and four received one dose of the JYNNEOS vaccination after onset of symptoms.

The researchers found that systemic symptoms, lesions, or both were present for a mean of 12 days at the time of treatment. The most common systemic symptoms were fever, headache, and fatigue. Twenty-three of the patients had genital and/or perianal lesions; 13 patients had fewer than 10 lesions over their entire body. All patients had lesion-associated pain. One patient received 21 days of treatment, while the rest received 14 days of treatment. On day 7 of therapy, 10 patients (40 percent) had complete resolution of lesions, while by day 21, 23 (92 percent) had resolution of lesions and pain. Tecovirimat was generally well tolerated, and none of the patients discontinued therapy. On day 7 of therapy, the most common adverse events included fatigue, headache, nausea, itching, and diarrhea (28, 20, 16, 8, and 8 percent, respectively).

"Oral tecovirimat was well tolerated by all patients with monkeypox infection, with minimal adverse effects. However, adverse effects could not always be differentiated from symptoms related to the infection," the authors write.

Abstract/Full Text