Before you begin using a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use this medication.
Alcohol: Consumption of alcohol in large amounts may decrease the ability to get an erection and may also temporarily decrease blood pressure, causing dizziness and fainting.
Blood pressure: Tell your doctor if you are taking medications to treat high blood pressure. The combination of these medications and sildenafil may add to the blood pressure-lowering effect of these medications. You should also let your doctor know if you have or have had low blood pressure.
Grapefruit juice: Grapefruit juice can increase the amount of sildenafil in your bloodstream. Do not drink grapefruit juice when taking this medication.
Hearing problems: If you experience a sudden decrease or loss of hearing you should seek medical attention immediately.
Heart conditions: If you have or have had heart disease or a heart attack or stroke, you should speak to your doctor before taking any medication for erectile dysfunction. If chest pains, dizziness, or nausea are experienced during sex, the exertion should be stopped and your doctor informed.
Kidney problems: If you have poor kidney function you may need lower doses of this medication. Kidney disease or reduced kidney function may cause this medication to build up in the body, causing side effects. If you have kidney problems, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.
Liver function: If you have poor liver function you may need lower doses of this medication. Liver disease or reduced liver function may cause this medication to build up in the body, causing side effects. If you have liver problems, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.
Nitrate-containing medications: Sildenafil should never be taken with any medications that contain nitrates. Blood pressure may suddenly drop to life-threatening levels if sildenafil is taken with any nitrate-containing medication (e.g., nitroglycerin tablets, spray, or patches) or any other nitrates (e.g., isosorbide dinitrate or amyl nitrite "poppers"). Dizziness, fainting spells, heart attack, or stroke may be experienced.
If use of a nitrate-containing medication is considered medically necessary, you must wait 48 hours after the last dose of sildenafil before taking a nitrate, and only under close medical supervision.
Penis deformation: As with other medications for erectile dysfunction, men with an anatomical deformation of the penis such as angulation, cavernosal fibrosis, or Peyronie's disease should be closely monitored by their doctors if they take this medication.
Prolonged erection: If an erection lasts longer than 4 hours (a rare occurrence), seek immediate medical assistance. If this condition is not treated quickly, tissue damage and permanent loss of the ability to have an erection could result.
Prostate problems: Tell your doctor if you are taking medications, such as alpha-blockers (e.g., doxazosin), to treat prostate problems, as the combination of these medications with sildenafil may add to the blood pressure-lowering effect of these medications.
Sexually transmitted infections: Sildenafil does not protect against sexually transmitted infections such as HIV.
Vision problems/eye conditions: If you experience a sudden loss of vision in one or both eyes or other vision related problems, contact your doctor immediately. Vision loss may be partial or complete. While in some cases the condition may improve over time, it can also be permanent.
This rare condition is more likely to occur if you have heart disease, high blood pressure, high cholesterol, diabetes, or eye problems, are more than 50 years old, or if you smoke. If you have any eye conditions, such as retinitis pigmentosa or non-arteritic anterior ischemic optic neuropathy (NAION), tell your doctor.
Pregnancy and breast-feeding: Sildenafil is not intended for use by women.
Children: Sildenafil is not intended for use by children or adolescents under 18 years of age.
Seniors: If you are 65 years of age or older, you may need a lower dose of this medication.