Men who take nitrate drugs, such as nitroglycerin, isosorbide mononitrate, or isosorbide dinitrate, should not take erectile dysfunction (ED) drugs. Like ED drugs, nitrate drugs dilate blood vessels. Taking the drugs together can cause a dangerous drop in blood pressure and loss of consciousness.
Men who have the following health problems may not be able to take ED drugs:
• Heart disease
• High or low blood pressure
• Liver disease
• Kidney disease
• Eye problems
• Stroke within the past 6 months
ED drugs can also interact with other medications, such as alpha-blockers, antibiotics, and blood thinners.