Pharmaceutical maker Aventis announced Tuesday that several users of its arthritis medication Arava have died in Japan. According to reports, 16 people taking Arava developed interstitial pneumonia, five of whom subsequently died. Aventis is advising physicians to stop prescribing the medication to patients suffering from respiratory problems. Arava was launched in Japan in September 2003.

Of the estimated 400,000 people who have taken Arava worldwide, 80 have developed interstitial pneumonia. A spokesperson for Aventis Pharma Japan said the company would immediately begin investigating whether Arava was responsible for the deaths.

In November 2003, Aventis and the FDA updated the prescribing information for Arava. In postmarketing experience worldwide, rare, serious hepatic injury, including cases with fatal outcome, have been reported during treatment with Arava. Most cases occurred within 6 months of therapy and in a setting of multiple risk factors for hepatotoxicity. Rare postmarketing reports of severe infections, including sepsis, which may be fatal, were also received. Most of the reports were confounded by concomitant immunosuppressant therapy and/or comorbid illness, which, in addition to rheumatoid disease, may predispose patients to infection.