isosorbide mononitrate (IMDUR, ISMO, MONOKET)

Watch out for Interactions Between Drugs for Erectile Dysfunction and Other Medications
January 2009
The article lists 56 drugs that can interact with the three drugs for erectile dysfunction (ED): sildenafil (VIAGRA), tadalafil (CIALIS) and vardenafil (LEVITRA). Eight of the drugs are either nitrates such as nitroglycerin or a certain group of high blood pressure drugs.In combination with ED drugs, these drugs can cause a dangerous fall in blood pressure that could lead to a heart attack or stroke. Thirty-two other drugs can inhibit the enzyme that helps the body to eliminate the ED drugs, resulting in abnormally high blood levels of the drugs and a potentially harmful "overdose" even though you are actually taking the recommended amount. The other 16 drugs speed up the metabolism of the ED drugs, thereby lowering the blood levels and reducing the effectiveness of the ED drugs.

A Review of Ranolazine (RANEXA) For Chronic Chest Pain
March 2007
Although the FDA medical officer in charge of reviewing ranolazine recommended that ranolazine's professional product labeling display a black box warning about potential disruption in the heart's electrical cycle, the drug does not have a black box warning.