Nitrate Cessation Profiles in Men Wishing to Use Sildenafil Citrate

A New Perspective on the Nitrate-Phosphodiesterase Type 5 Inhibitor Interaction

BACKGROUND

Nitrates and nitrate-containing compounds are vasodilators used for the treatment of angina and heart failure. Phosphodiesterase type 5 inhibitors used for the treatment of erectile dysfunction are also vasodilators, and when taken together with nitrates, synergistic effects that enhance hypotensive effects may occur. Phosphodiesterase type 5 inhibitors are therefore contraindicated in patients taking organic nitrates.

METHODS AND RESULTS

A literature review was performed to provide a historical overview of different phosphodiesterase type 5 inhibitors and nitrates and their interaction. The pharmacologic characteristics of phosphodiesterase type 5 inhibitors and nitrates are reviewed, and clinical recommendations for treating cardiovascular disease in men taking phosphodiesterase type 5 inhibitors are discussed. Pharmacologic and adverse drug reactions between nitrates and phosphodiesterase type 5 inhibitors are dependent on many variables. Organic nitrates remain an absolute contraindication in men treated with phosphodiesterase type 5 inhibitors. In general, nitrates may be taken 24 hours after the last dose of short-acting phosphodiesterase type 5 inhibitors and 48 hours after the last dose of long-acting phosphodiesterase type 5 inhibitors.

CONCLUSIONS

This literature review determined that the use of phosphodiesterase type 5 inhibitors with nitrates is a contraindication, with the duration between the last dose of phosphodiesterase inhibitor and nitrate use generally varying between short- and long-acting phosphodiesterase type 5 formulations. Patients receiving nitrates who wish to use phosphodiesterase type 5 inhibitors should be educated regarding the interaction and should be evaluated to determine whether nitrate treatment can be discontinued. Further research is needed to determine how soon phosphodiesterase type 5 inhibitors can be restarted after a patient has taken a nitrate and the effect of high and low phosphodiesterase type 5 inhibitor doses on the interaction effect.

Sexual function in patients with chronic angina pectoris

Drugs for erectile dysfunction (ED) may be contraindicated with nitrates commonly used to treat patients with angina pectoris, and certain antianginal therapies may worsen ED. The American Heart Association and the Princeton Consensus Conference panel of experts recommend that patients with coronary artery disease and ED who experience angina pectoris undergo full medical evaluations to assess the cardiovascular risks associated with resuming sexual activity before being prescribed therapy for ED. Current antianginal therapies include β blockers, calcium channel blockers, short- and long-acting nitrates, and ranolazine, a late sodium current inhibitor. Short- and long-acting nitrates remain a contraindication with phosphodiesterase-5 inhibitors commonly used to treat patients with ED, and the benefits of the other antianginal therapies must be weighed against their effects on cardiovascular health and erectile function. In conclusion, patients with coronary artery disease and ED who wish to initiate phosphodiesterase-5 inhibitor therapy and need to discontinue nitrate therapy need treatment options that manage their angina pectoris effectively, maintain their cardiovascular health, and provide the freedom to maintain their sexual function.