Losartan: a study of pharmacovigilance data on 14,522 patients

The objective of this study was to undertake a post- marketing safety surveillance study of losartan, the first specific angiotensin-II receptor antagonist to be marketed in England. It is a non-interventional observational cohort study using the technique of prescription-event monitoring. Subjects who took part in the study were from 14 522 patients treated by general practitioners in England. We recorded adverse drug reactions, adverse events, reasons for stopping the drug, pregnancies and deaths. The results were that general practitioners considered the drug to have been effective in 85.9% of the patients evaluated for effectiveness. Dizziness, malaise, lassitude, nausea, cough and headache were among the most frequently reported adverse drug reactions, reasons for stopping the drug and events of highest incidence density. None of the deaths that occurred were attributed to losartan and no serious unexpected adverse reactions or interactions were identified. In conclusion losartan has an acceptable safety profile and the study confirms the safety information given in the current Summary of Product characteristics for losartan.