• you are allergic to any ingredient in Zenegra
• you have been advised by your doctor to avoid sexual activity because of heart problems
• you are taking nitrates (eg, isosorbide, nitroglycerin) in any form (eg, tablet, capsule, patch, ointment), or nitroprusside
• you use certain recreational drugs called "poppers" (eg, amyl nitrate or nitrite, butyl nitrate or nitrite)
• you take another PDE5 inhibitor (eg, tadalafil, vardenafil) or another medicine that contains sildenafil.

Contact your doctor or health care provider right away if any of these apply to you.

Some medical conditions may interact with Zenegra . Tell your doctor or pharmacist if you have any medical conditions, especially if any of the following apply to you:

• if you are taking any prescription or nonprescription medicine, herbal preparation, or dietary supplement
• if you have allergies to medicines, foods, or other substances
• if you have a deformed penis (eg, cavernosal fibrosis, Peyronie disease), blood cell problems (eg, leukemia, multiple myeloma, sickle cell anemia), or any other condition that may increase the risk of a prolonged erection (priapism)
• if you have a history of a prolonged (more than 4 hours) or painful erection (priapism)
• if you have a history of certain eye problems (eg, macular degeneration, optic neuropathy, retinitis pigmentosa, sudden vision loss in one or both eyes) or hearing problems (eg, ringing in the ears, decreased hearing, hearing loss)
• if you have a history of liver or kidney problems, lung problems (eg, pulmonary veno-occlusive disease), high or low blood pressure, ulcers, bleeding problems, heart problems (eg, angina, aortic stenosis, heart failure, irregular heartbeat), or blood vessel problems
• if you have a history of heart attack, stroke, or life-threatening irregular heartbeat, especially within the past 6 months.

Some medicines may interact with Zenegra. Tell your health care provider if you are taking any other medicines, especially any of the following:

• Alpha-blockers (eg, doxazosin), medicines for high blood pressure, nitrates (eg, isosorbide, nitroglycerin), or nitroprusside because severe low blood pressure with dizziness, lightheadedness, and fainting may occur
• Azole antifungals (eg, itraconazole, ketoconazole), H₂ antagonists (eg, cimetidine), HIV protease inhibitors (eg, ritonavir, saquinavir), macrolide antibiotics (eg, erythromycin), narcotic analgesics (eg, dihydrocodeine), or telithromycin because they may increase the risk of Zenegra's side effects
• Bosentan or rifampin because they may decrease Zenegra's effectiveness.

This may not be a complete list of all interactions that may occur. Ask your health care provider if Zenegra may interact with other medicines that you take. Check with your health care provider before you start, stop, or change the dose of any medicine.

Important safety information: