Sildenafil 100mg (Generic Viagra)

What is Sildenafil used for​​​?

Sildenafil is used to treat erectile dysfunction, a condition where you are unable to get or keep an erection firm enough to have sexual intercourse. It works by relaxing the blood vessels in your penis, allowing blood to flow into your penis when you get sexually excited. This medicine will only help you to get an erection if you are sexually stimulated. Therefore it is taken on an as-needed basis.

This medication may also be used for other conditions. Check with your healthcare professional if you are unsure why you are given this medicine.

Dosage and how to use​

• Do not take more than once a day or the dose prescribed for you.
• It usually starts to work within 1 hour and effective up to 4 hours before sexual activity. 
• This medication should be taken before food, on an empty stomach. You may find that this medicine takes longer to start working if you take it with a high-fat meal (such as cheeseburger and French fries)

How effective is Sildenafil for Erectile Dysfunction?

Sildenafil efficacy, determined as the ability to achieve and maintain an erection sufficient for sexual intercourse, was demonstrated in all 21 studies and was maintained in long-term extension studies (one year). In fixed-dose studies, the proportions of patients reporting that treatment improved their erections were 62% (25 mg), 74% (50 mg) and 82% (100 mg) compared to 25% on placebo.

What are the possible side effects of Sildenafil?​

• Facial flushing where the skin on your face feels hot
• Headache 
• Visual disturbances (including blurring of vision, blue tinge in vision)
• Indigestion or stomach pain
• Nosebleed
• Very rarely, priapism (an erection that will not go away) - If you have an erection that lasts more than 4 hours, get medical help right away. If it is not treated right away, priapism can permanently damage your penis.

What precautions should I take?

Inform your healthcare professional if: 

• You are allergic to this medication or any of the other ingredients of this medication
• You are taking medicines called Nitrates (such as sublingual nitroglycerin (also known as Glycerin Trinitrate or GTN), Isosorbide Mononitrate or Isosorbide Dinitrate), as the combination may lead to a dangerous fall in your blood pressure. Nitrates must be withheld at least 24 hours after the last dose of Sildenafil or Vardenafil, and 48 hours after the last dose of Tadalafil. 
• Tell your doctor if you are taking any of these medicines which are often given for relief of angina (chest pain).  If you are not certain, ask your healthcare professional. 
• You are taking medicines called Alpha-1 Blockers (such as Tamsulosin, Terazosin, Prazosin, Alfuzosin), as the combination may further lower your blood pressure. In order to reduce the chances of these symptoms occurring, you should be on a regular daily dose of your Alpha-blocker before you start drugs for erectile dysfunction.
• You recently had a stroke or a heart attack, low blood pressure or uncontrolled high blood pressure 
• You have severe heart, liver or kidney  problem 
• You have certain rare inherited eye diseases (such as retinitis pigmentosa)
• You have a stomach ulcer or bleeding problem
• You have sickle cell anaemia (an abnormality of red blood cells)
• You have a deformity of your penis 

What other medications and foods should I avoid when taking Sildenafil?

Avoid taking grapefruit, or grapefruit juice as they may interact with your medication and increase the risk of side-effects.

Drinking alcohol can temporarily weaken your ability to get an erection and may increase the blood pressure lowering effects of the medication, which can be dangerous. To get the maximum benefit from your medication, it is advisable not to drink excessive amounts of alcohol before taking this medication. 

Inform your healthcare professional if you are taking or intend to take any other medication, supplements, traditional medications or herbal remedies.

This includes certain medications such as:

• Antibiotics
• Anti-fungal medications
• Medications used to treat human immunodeficiency virus (HIV) infection

Handling and storage

• Store in a cool and dry place, away from direct sunlight. Keep this medication away from children. 
• Pack this medication into a black trash bag and seal it tightly before throwing into the rubbish chute or bin.

If you take more than the recommended dose, please seek medical advice immediately. The information provided on this page does not replace information from your healthcare professional. Please consult your healthcare professional for more information.

References

https://www.healthhub.sg/a-z/medications/337/Sildenafil

https://www.mims.com/singapore/drug/info/viagra