An observational cohort study investigating the cardiovascular safety of tadalafil when prescribed in primary care in England: mortality due to ischaemic heart disease

Abstract

To examine the cardiovascular safety of tadalafil, a phosphodiesterase type-5 inhibitor used for treating erectile dysfunction in patients prescribed this drug by general practitioners (GPs) in England in 2003, focusing on mortality due to ischaemic heart disease (IHD). Patients in this observational cohort study were identified from dispensed prescriptions for tadalafil issued by GPs from February to November 2003. Demographic and outcome data were requested from patients' GPs using a postal questionnaire. A standardized mortality ratio (SMR) was calculated using indirect standardization for all deaths from IHD or myocardial infarction (MI) in male patients who were prescribed tadalafil, regardless of whether they were taking tadalafil at the time, compared to those in the English male population (2002). Clinical information was obtained for 6266 patients; patient sex could not be confirmed for 37 but in the remaining 6229 the median age was 61 years (interquartile range 53-68). The age was not specified for 2361 (37.7%) of the patients. Excluding patients not taking tadalafil at the time of the event, cardiovascular events included chest pain in 20, angina in 18, MI in 15 (including six fatal) and IHD in 11 (including five fatal). There were also six deaths where the cause was not ascertained; five of these patients were known to be male. Comparison of mortality due to IHD or MI for men with those in the English male population (2002) provided an SMR of 0.91 (95% confidence interval 0.50-1.48). The results from this study suggest a similar incidence of death due to IHD or MI in men prescribed tadalafil to that in the male English population. However, due to possible under-reporting and the limitations of using an external comparator, these results should be interpreted in context with other studies on the cardiovascular effects and safety of tadalafil.