As coprescribing drugs for erectile dysfunction and oral organic nitrates for ischemic heart disease (IHD) surged, cardiovascular adverse events did not significantly increase, a new study finds.
The authors of the new research specifically examined how frequently phosphodiesterase type 5 (PDE5) inhibitors, such as Viagra, were prescribed. The U.S. Food and Drug Administration and the European Medicines Agency have warned that these drugs for erectile dysfunction are contraindicated for use with nitrates because of concerns about cardiovascular risks.
"Small, randomized, pharmacologic studies have reported an amplified decrease in blood pressure during controlled coexposure with nitrates and [phosphodiesterase type 5 inhibitors], both in healthy participants and in participants with IHD," wrote lead author Anders Holt, MD, of Copenhagen University Hospital–Herlev and Gentofte and colleagues, in Annals of Internal Medicine. "Potentially, this increases the risk for vascular ischemic events including myocardial infarction and stroke."
But there is a scarcity of real-world data showing that using both types of drugs together increases these risks, the researchers noted.
To address this knowledge gap, Holt and colleagues conducted a retrospective study involving 249,541 Danish men with IHD. In this overall population, from 2000 to 2018, prescriptions for PDE5 inhibitors increased 10-fold, from 3.1 to 30.9 prescriptions per 100 persons per year. Within a subgroup of 42,073 patients continuously prescribed oral organic nitrates, PDE5-inhibitor prescriptions jumped twice that magnitude, from 0.9 to 19.7 prescriptions per 100 persons per year.
