Paracetamol: not as safe as we thought? A systematic literature review of observational studies

Objectives We conducted a systematic literature review to assess the adverse event (AE) profile of paracetamol. Methods We searched Medline and Embase from database inception to 1 May 2013. We screened for observational studies in English, which reported mortality, cardiovascular, gastrointestinal (GI) or renal AEs in the general adult population at standard analgesic doses of paracetamol. Study quality was assessed using Grading of Recommendations Assessment, Development and Evaluation. Pooled or adjusted summary statistics were presented for each outcome. Results Of 1888 studies retrieved, 8 met inclusion criteria, and all were cohort studies. Comparing paracetamol use versus no use, of two studies reporting mortality one showed a dose–response and reported an increased relative rate of mortality from 0.95 (0.92 to 0.98) to 1.63 (1.58 to 1.68). Of four studies reporting cardiovascular AEs, all showed a dose–response with