PDE5 inhibitor plus nitrates do not induce adverse events in IHD patients

Use of phosphodiesterase type 5 (PDE5) inhibitors has increased 20-fold from 2000 to 2018, according to a study of Danish patients with ischaemic heart disease (IHD) who were taking nitrates. In addition, no statistically significant association has been observed between concomitant use of PDE5 inhibitors and cardiovascular adverse events.

This nationwide case-crossover study included 249,541 male patients with International Classification of Diseases, 10th Revision (ICD-10) codes for IHD, including those with a continuing prescription for nitrates and a new, filled prescription for PDE5 inhibitors, from 2000 to 2018.

The investigators measured two composite outcomes: 1) cardiac arrest, shock, myocardial infarction, ischaemic stroke, or acute coronary arteriography and 2) syncope, angina pectoris, or drug-related adverse event.

Of the patients, 42,073 had continuing prescriptions for nitrates. The prescription rate for PDE5 inhibitors in men with IHD who were taking nitrates increased from an average of 0.9 prescriptions (95 percent confidence interval [CI], 0.5‒1.2) per 100 persons per year in 2000 to 19.5 prescriptions (95 percent CI, 18.0‒21.1) in 2018.

No statistically significant association existed between the coprescription of nitrates with PDE5 inhibitors and the risk for either composite outcome (first outcome: odds ratio [OR], 0.58, 95 percent CI, 0.28‒1.13; second outcome: OR, 0.73, 95 percent CI, 0.40‒1.32).

As for the study’s limitation, “[a]n assumption was made that concurrently filled prescriptions for nitrates and PDE5 inhibitors equaled concomitant use,” the investigators said.