Drug Class: Phosphodiesterase type 5 (PDE5) inhibitor
Indications: Sildenafil is used to treat erectile dysfunction (ED) in men. It works by increasing blood flow to the penis, which helps achieve and maintain an erection. It is also used to treat pulmonary arterial hypertension (PAH) in both men and women. In this case, it works by relaxing blood vessels in the lungs, allowing blood to flow more easily.
Dosage Forms and Strengths: Sildenafil is available as oral tablets in strengths of 25 mg, 50 mg, and 100 mg.
Dosage and Administration: The recommended starting dose of sildenafil for most men is 50 mg taken 1 hour before sexual activity. The dose can be increased or decreased based on individual response and tolerability, up to a maximum of 100 mg or a minimum of 25 mg. Sildenafil should not be taken more than once per day. For the treatment of PAH, the usual dose is 20 mg three times per day.
Contraindications: Sildenafil is contraindicated in patients who are taking nitrates, which are commonly used to treat angina (chest pain). It should also not be used in patients with severe liver or kidney disease, low blood pressure, or a history of stroke or heart attack.
Warnings and Precautions: Sildenafil can cause a sudden decrease in blood pressure, especially when taken with nitrates. It should not be used in patients with severe liver or kidney disease, low blood pressure, or a history of stroke or heart attack. Sildenafil should be used with caution in patients with bleeding disorders or those taking blood thinners. It may also interact with certain medications, such as alpha-blockers, and should not be used with other PDE5 inhibitors.
Adverse Reactions: The most common side effects of sildenafil include headache, facial flushing, indigestion, and nasal congestion. Other side effects may include dizziness, nausea, and back pain. In rare cases, sildenafil can cause serious side effects such as sudden hearing loss, vision changes, or an erection lasting more than 4 hours.
Drug Interactions: Sildenafil can interact with nitrates, alpha-blockers, and blood thinners, as well as other PDE5 inhibitors. It should not be used with these medications without careful medical supervision.
Pregnancy and Lactation: Sildenafil is not recommended for use during pregnancy or while breastfeeding.
Overdose: In case of overdose, seek emergency medical attention. Symptoms may include chest pain, nausea, irregular heartbeat, and fainting.
Monitoring and Laboratory Tests: There are no specific monitoring or laboratory tests required for patients taking sildenafil. However, patients should be monitored for potential side effects and changes in blood pressure.