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Sildenafil (Viagra)

What is sildenafil?

Sildenafil (brand name: Viagra) is a medicine that doctors prescribe to help men who have erectile dysfunction have sex. Erectile dysfunction is the inability of the penis to become rigid (hard), or to stay rigid long enough to finish having sex. Sildenafil helps maintain an erection.

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How should I take sildenafil?

Follow your doctor's instructions. Usually, a man takes 1 tablet 30 minutes to 1 hour before he plans to have sex. You should not take more than 1 tablet in 24 hours. The medicine comes in tablets of 25 mg, 50 mg and 100 mg. Most patients start with 50 mg.

Even if you take sildenafil, you still need physical and mental stimulation and desire to have an erection. If your first dose of Viagra doesn't help, call your doctor. Your doctor may want to change your tablet strength.

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What are the side effects?

Sildenafil has some common side effects:

  • Headache
  • Flushing (face and upper body turning red and warm)
  • Stomach upset
  • Runny nose (sniffles)
  • Vision changes (things look blue)
Headache is the most common side effect. Vision changes are the least common. Talk to your doctor if you have any side effect that bothers you.

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Can everyone use sildenafil?

No. You shouldn't use this medicine if you take any of these forms of nitroglycerin or any other nitrates:

  • Isosorbide mononitrate (brand names: Ismo, Monoket, Imdur)
  • Isosorbide dinitrate (brand names: Isordil, Sorbitrate)
  • Sublingual nitroglycerin tablets or spray (brand names: Nitrostat, Nitrolingual Spray)
  • Transdermal nitroglycerin patches or paste (brand names: Minitran, Nitro-Dur, Transderm-Nitro)
You also shouldn't take sildenafil if you are taking other medicines for erectile dysfunction.

If you use sildenafil and get chest pains, be sure to tell the paramedics, nurses or doctors at the hospital that you use it and how long ago it was that you last took a tablet.

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Source

Written by familydoctor.org editorial staff.

Newer Pharmacologic Alternatives for Erectile Dysfunction by Anthony J. Viera, LT, MC, USNR, Timothy L. Clenney, LCDR, MC, USNR, Donald W. Shenenberger, LT, MC, USNR, and Gordon F. Green, CDR, MC, USNR (American Family Physician September 15, 1999, http://www.aafp.org/afp/990915ap/1159.html)

Reviewed/Updated: 08/06
Created: 09/00