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.
Bleeding problems: Sildenafil may cause your body to take longer to stop bleeding. If you have bleeding problems or a bleeding disorder, 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.
Blood pressure: Sildenafil can cause a rapid decrease in blood pressure that may add to the blood pressure-lowering effect of other medications. Tell your doctor if you are taking medications to treat high blood pressure. If you are taking medication for high blood pressure, 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.
Grapefruit juice: Grapefruit juice can increase the amount of sildenafil in your blood. Do not drink grapefruit juice while taking this medication.
Heart or blood vessel problems: Sildenafil can make heart or blood vessel problems worse. If you have had a heart attack, stroke, or life-threatening abnormal heart rhythm within the last 6 months, or have angina, chest pain, an irregular heartbeat, or high or low blood pressure, 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.
Lung problems: Sildenafil is not recommended for people with a form of high blood pressure in the lungs called pulmonary veno-occlusive disease. If you have pulmonary veno-occlusive disease or experience sudden cough, shortness of breath, chest pain, or rapid breathing, talk to your doctor before taking this medication.
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.
Penis deformation: Men with an anatomical deformation of the penis such as angulation, cavernosal fibrosis, or Peyronie's disease should be closely monitored by their doctor while taking this medication.
Prolonged erection: Tell your doctor if you have ever had an erection that lasted longer than 4 hours, or have sickle cell anemia or leukemia, before taking this medication.
Prostate problems: Tell your doctor if you are taking medications to treat prostate problems, such as alpha-blockers (e.g., doxazosin), as sildenafil combined with these medications may cause dangerously low blood pressure.
Vision problems: If you have or have had a temporary decrease or permanent loss of vision in one or both eyes, including a condition called non-arteritic anterior ischemic optic neuropathy (NAION), or if you have retinitis pigmentosa, tell your doctor before taking this medication.
This medication can cause partial or complete vision loss that may be temporary or permanent. If you experience a sudden loss of vision in one or both eyes or other vision-related problems, contact your doctor immediately. If you do experience vision changes, do not drive or operate machinery until your vision returns to normal.
Pregnancy: This medication should not be used during pregnancy unless the benefits outweigh the risks. If you become pregnant while taking this medication, contact your doctor immediately.
Breast-feeding: It is not known if sildenafil passes into breast milk. If you are a breast-feeding mother and are taking this medication, it may affect your baby. Talk to your doctor about whether you should continue breast-feeding.
The safety and effectiveness of this medication have not been established for children with pulmonary hypertension.