What is Viagra?

Viagra is a product containing Sildenafil citrate as an active ingredient. Sildenafil is a class of medications called phosphodiesterase (PDE) inhibitors.

What Viagra is used for?

Viagra is used to treat erectile dysfunction, more commonly known as impotence, in men. This is when a man man cannot get, or keep , a hard erect penis suitable for sexual activity.

If you are taking sildenafil to treat erectile dysfunction, you should know that it does not cure erectile dysfunction or increase sexual desire.

Viagra is only available with a doctor’s prescription.

How does it work?

It works by relaxing the blood vessels in your penis when you are sexually excited. This allows blood to flow into your penis, allowing you to get an erection in the natural way.

What is the dosage for Viagra?

In adults 50mg once daily, taken approximately 1 hour before sexual activity . The dose maybe may be increased to 100mg or decreased to 25mg. Maximum dos is 100mg once daily. Initial dose for elderly over 65 years old is 25mg and may increase to 50-100mg based on efficacy and tolerability.

How to take Viagra ?

Take Viagra exactly as your doctor has prescribed. Your doctor will decide the correct dose for you depending on your condition and response.

Take your dose of Viagra about one hour before you intend to have sex. Swallow the tablet whole with a full glass of water

Do not take more than one dose of Viagra a day.

Follow all directions given to you by your doctor and pharmacist carefully.

The amount of time Viagra takes to start working varies from person to person, but it normally takes between half an hour and one hour. It may takes longer to work if you take it with a heavy meal. Viagra will work only if you are sexually excited.

What precautions should be taken before using Viagra ?

Inform your doctor and pharmacist of the following:

  • Any allergies that you may have to medicines or any other substances ( i.e. Foods, preservatives, dyes)
  • Any other medicines that you are taking at the time (both prescription and over the counter)
  • You have any other heart or blood vessel problems
  • You have previously had sudden loss of eyesight in one or both eyes
  • You have any of the following medical conditions: diabetes, kidney or liver problems, leukaemia, multiple myeloma, any disease or deformity of your penis, any bleeding disorder , stomach ulcer and colour vision problems
  • You are receiving any other treatment for impotence
  • You have any other medical conditions

Special precautions: Taking other medicines

  • You should tell your doctor pharmacist if you are taking any other medicines, including medicines you buy without a prescription from a pharmacy, supermarket or health food shop
  • Some medicines and Viagra may interfere with each other. Eg : Cimetidine, antifungal(ketoconazole and itraconazole), antibiotics (eg : erythromycin and rifampicin). Ask your doctor or pharmacist for advise.

What are the side effects of Viagra ?

Tell your doctor or pharmacist as soon as possible if any of these symptoms are severe or do not go away.

  • Headache, dizziness
  • FlushingIndigestion
  • Stuffy nose
  • Changes in vision such as blurring, a blue colour to your vision or a greater awareness of light
  • Diarrhoea
  • Urinary tract infections
  • Rash

If you notice any other symptoms that worry you, consult with your doctor

Is there any condition where Viagra is contraindicated?

Viagra is contraindicated in the following medical conditions:

  • You are using amyl nitrite.
  • You have heart or blood vessel problems that make sexual intercourse inadvisable
  • Hypersensitivity to sidenafil
  • You have severe liver problems
  • You have loss you vision in one or both eyes
  • You have eye disease called retinitis pigmentosa


Last reviewed : 20 March 2015
Writer : Norhayati bt. Musa
Reviewer : Siti Nurul Fathihah bt. Baharudin
  : Che Pun bt. Bujang