[Status of use and side effects of atovaquone for the treatment and prevention of pneumocystis pneumonia in HIV infected patients in Japan--from 1997 to 2012--The Clinical Study Group for AIDS Drugs, supported by Health and Labor Science Grants from the Ministry of Health, Labor and Welfare, Japan].

PURPOSE: Atovaquone is effective and well-tolerated for the treatment of mild or moderate Pneumocystis pneumonia (PCP) and the prevention of PCP. When atovaquone was not yet approved in Japan, it was supplied by the Clinical Study Group for AIDS Drugs, which has been supported by the Japan Health Science Foundation since 1997. We investigated the status of use and the reported side effects, since atovaquone has recently been approved and made available in Japan. METHOD: We retrospectively examined the application and adverse events associated with atovaquone use between January 1997 and March 2012. RESULTS: During this period, there were 721 new applications, increasing over time, with the highest rate of increase observed in recent years. Fifty-seven adverse events in 39 patients were reported. Drug eruption was the most common side effect (20 cases), followed by cytopenia (11 cases), fever (10 cases), and liver dysfunction (8 cases). Two deaths were reported (one with an unknown correlation, another with no comments provided). One case of liver dysfunction attributable to atovaquone was severe. In this case, the AST and ALT levels increased to 1,921 IU/L, and 1,062 IU/L, respectively on day 4 of atovaquone administration, but these levels improved after atovaquone discontinuation. No other severe side effects were reported. DISCUSSION: This study revealed that as in other countries, few side effects caused by atovaquone were reported in Japan. Moreover, there were no side effects unique to the Japanese population. However, caution is required when administering atovaquone, because a low incidence of severe atovaquone-induced liver dysfunction has been reported.