Abstract

Objective: To monitor the safety of valsartan using the technique of Prescription Event Monitoring (PEM), in patients prescribed this drug by general practitioners (GPs) in England.

Method: PEM is a non-interventional observational cohort technique. Exposure data were obtained from dispensed prescriptions issued between December 1996 to November 1998. Outcome data were obtained by sending questionnaires to prescribing GPs.

Results: The cohort comprised 12 881 patients. Events most frequently reported as suspected adverse drug reactions (ADRs) were malaise/lassitude (37; 0.3% of total cohort), dizziness (19; 0.1%) and unspecified side effects (57; 0.4%). Events with highest incidence density (ID1 per 1000 patient-months of treatment) in the first month of treatment were: malaise/lassitude (15.6), dizziness (11.8) and headache/migraine (10.9). Most frequent reasons for stopping valsartan were: not effective (847; 6.6% of total cohort), malaise/lassitude (265; 2.1%) and dizziness (146; 1.1%). No unexpected serious adverse events were identified. Other events assessed as possibly related to valsartan use were: impotence (37), dizziness (19), cough (9), facial oedema (5), hyperkalemia (3) and angioneurotic oedema (1). There were four reports of exposure during pregnancy and 203 deaths (1.5%) in this cohort.

Conclusion: This study monitored the safety profile of valsartan in a large cohort of patients in general practice in England. No untoward features other than dizziness were been identified that were not mentioned in the prescribing guidance.