Viagra (Sildenafil): Uses, Dosage, Side Effects, and Precautions

What is Viagra?

Viagra is a brand name for sildenafil citrate, a phosphodiesterase type 5 (PDE5) inhibitor used to treat erectile dysfunction (ED). It increases blood flow to the penis during sexual stimulation, helping men achieve and maintain an erection.

Uses

• Treatment of erectile dysfunction to improve ability to achieve and maintain an erection suitable for sexual activity

• Occasionally used off-label for pulmonary arterial hypertension

Dosage and Administration

• Typical dose: 50 mg taken orally about 30 to 60 minutes before sexual activity

• Dose can be adjusted between 25 mg to 100 mg depending on effectiveness and tolerability

• Should not be taken more than once per day

• Can be taken with or without food; high-fat meals may delay onset of action

Common Side Effects

• Headache

• Flushing (redness and warmth of the face and neck)

• Indigestion or upset stomach

• Nasal congestion or runny nose

• Dizziness

• Visual disturbances such as blurred vision or increased sensitivity to light

• Muscle or back pain

Serious Side Effects (Seek Medical Attention)

• Priapism (prolonged erection lasting more than 4 hours)

• Sudden loss of vision or hearing

• Chest pain or irregular heartbeat

• Severe allergic reactions including swelling and difficulty breathing

• Severe hypotension resulting in fainting or dizziness

Precautions and Warnings

• Avoid use with nitrates or nitric oxide donors to prevent severe hypotension

• Use cautiously in patients with cardiovascular diseases or risk factors

• Avoid alcohol consumption during treatment

• Inform healthcare provider of all medications and health conditions

• Not indicated for women or children

• Avoid combining with other PDE5 inhibitors

Mechanism of Action

Sildenafil inhibits PDE5 enzyme, leading to smooth muscle relaxation and increased blood flow in the corpus cavernosum during sexual stimulation, facilitating erection.

Expected Outcomes

• Improved erectile function and sexual satisfaction

• Ability to achieve and maintain erections adequate for intercourse