Is my erectile dysfunction most likely temporary or chronic? Get treatment for alcohol or drug problems. Slowly pull back the plunger until the required dose. Tell your doctor if any of these symptoms are severe or do not go away: headache. If you are taking sildenafil to treat PAH, you will probably take sildenafil three times a day with or without food. For treatment of erectile dysfunction: For oral dosage form tablets : Adults up to 65 years of age—50 milligrams mg as a single dose no more than once a day, 1 hour before sexual intercourse. To provide you with the most relevant and helpful information, and understand which information is beneficial, we may combine your email and site usage information with other information we have about you.VIAGRA is available by prescription only in 25 mg, 50 mg, and mg tablets. Patients should always ask their doctors for medical advice about adverse events. You are .  · Proper Use. Drug information provided by: Merative, Micromedex ®. Use sildenafil exactly as directed by your doctor. Do not use more of it and do not use it . Your doctor or other health care professional can recommend one for you based on these factors, other health conditions you have and any other medicines you .