Take 60 minutes before. Once taken, do not take it again within 24 hours. Its effectiveness lasts 8 to 9 hours.
Do not use Valif 20mg if:
you are allergic to any ingredient in Valif 20mg;
you have severe liver problems or severe kidney problems that require dialysis;
you have had a heart attack, stroke, or life-threatening irregular heartbeat within the past 6 months;
you have been advised by your doctor to avoid sexual activity because of heart problems;
you have certain heart problems (e.g., unstable angina, severe heart failure), low blood pressure, or uncontrolled high blood pressure;
you use certain recreational drugs called poppers (e.g., amyl nitrate, butyl nitrate).
you have certain hereditary degenerative eye problems (e.g., retinitis pigmentosa) ;
you are taking nitrates (e.g., isosorbide, nitroglycerin) in any form (e.g., tablet, capsule, patch, ointment), nitroprusside, or certain antiarrhythmics (e.g., quinidine, amiodarone);
Contact your doctor or health care provider right away if any of these apply to you.
Valif 20mg may cause dizziness, drowsiness, fainting, or blurred vision. These effects may be worse if you take it with alcohol or certain medicines. Use Valif 20mg with caution. Do not drive or perform other possibly unsafe tasks until you know how you react to it.
Valif 20mg may cause dizziness, lightheadedness, or fainting; alcohol, hot weather, exercise, or fever may increase these effects. To prevent them, sit up or stand slowly, especially in the morning. Sit or lie down at the first sign of any of these effects.
Do not use other medicines or treatments for erectile dysfunction while you are taking Valif 20mg.
Possible Side Effects:
All medicines may cause side effects, but many people have no, or minor, side effects. Check with your doctor if any of these most common side effects persist or become bothersome.
dizziness, flushing, headache, heartburn, stuffy or runny nose, upset stomach.
Seek medical attention right away if any of these severe side effects occur:
severe allergic reactions (rash, hives, itching, difficulty breathing, tightness in the chest, swelling of the mouth, face, lips, or tongue), back or muscle pain, chest pain, fainting, prolonged, painful erection, ringing in the ears, severe or persistent dizziness, severe or persistent vision changes, sudden hearing loss.