CHOLESTATIC HEPATITIS ASSOCIATED WITH FLUCLOXACILLIN

Objective: To estimate the frequency of cholestatic hepatitis of uncer tain origin occurring among persons who had recently received flucloxa cillin, a drug which has recently been reported as causing cholestatic hepatitis, and to compare this frequency with that related to oxytetr acycline, a drug which has seldom been reported as causing this disord er. Design: A retrospective cohort study using data automatically reco rded on general practitioners' office computers. Setting: Some 600 gen eral practices in the United Kingdom. Subjects: 132 087 people who rec eived flucloxacillin and 145 844 people who received oxytetracycline. Main outcome measure: Clinically documented cholestatic hepatitis of u ncertain origin diagnosed 1-45 days after a prescription for flucloxac illin, 46-90 days after a prescription for flucloxacillin and, for com parison, 1-45 days after a prescription for oxytetracycline. Results: There were 10 cases of cholestatic hepatitis of uncertain origin diagn osed within 45 days of receiving flucloxacillin that were either chara cteristic of or consistent with a syndrome recently described as being associated with this drug; there was one such case 46-90 days after a prescription for flucloxacillin; there were three such cases 1-45 day s after a prescription for oxytetracycline. Conclusion: Flucloxacillin is a likely cause of cholestatic hepatitis. The risk is estimated to be in the range of 7.6 per 100 000 users (95% confidence interval, 3.6 -13.9).