Cefmetazole postmarketing surveillance in Japan

The Sankyo Company Ltd had conducted a postmarketing surveillance programme on cefmetazole sodium since its marketing introduction in Japan. Two data collection approaches were used: a survey in which participating physicians provided complete information on all their patients who received cefmetazole for treatment of infection, and two voluntary reporting systems--one sponsored by Sankyo and the other by the Japanese Ministry of Health and Welfare. Eight years' data from this programme are presented. The survey allowed quantitative determination of estimated incidence rates of adverse drug reactions (ADRs) in the overall population. A total of 118,318 patients were enrolled in the survey; this resulted in a sensitivity adequate to detect ADRs that occur in only one of 10,000 patients. Two per cent of the survey patients reported ADRs (either clinical events or laboratory abnormalities or both). The most frequent clinical ADRs were cutaneous reactions, followed by gastrointestinal symptoms. The most common laboratory abnormalities were in hepatic function tests. Rare and potentially serious events reported in the voluntary systems included anaphylactic shock, pseudomembranous colitis, and haemorrhagic tendency. Disulfiram-like reactions associated with alcohol ingestion were also reported rarely. With appropriate monitoring, cefmetazole is safe and well tolerated for the treatment of infection.