Sildenafil Citrate(sill den’ ah fill)
Revatio, Viagra
PREGNANCY CATEGORY B
Drug Classes
Impotence drug
Phosphodiesterase inhibitor
Therapeutic Actions
Selectively inhibits cGMP-specific phosphodiesterase type 5. The mechanism of penile erection involves the release of nitric oxide into the corpus cavernosum of the penis during sexual stimulation. Nitrous oxide activates cGMP, which causes smooth muscle relaxation, allowing the flow of blood into the corpus cavernosum. Sildenafil prevents the breakdown of cGMP by phosphodiesterase, leading to increased cGMP levels and prolonged smooth muscle relaxation, promoting the flow of blood into the corpus cavernosum and decreasing pressure in the pulmonary bed.
Indications
Treatment of ED in the presence of sexual stimulation (Viagra)
Treatment of pulmonary arterial hypertension to improve exercise ability (Revatio)
Unlabeled uses: Esophageal motility disorders, anal fissures, antidepressant/antipsychotic-induced sexual dysfunction, pulmonary hypertension in children, Raynaud phenomenon, sexual dysfunction in women
Contraindications and Cautions
Contraindicated with allergy to any component of the tablet, concomitant use of nitrates; contraindicated for women or children if used for sexual dysfunction.
Use cautiously with hepatic or renal impairment; with anatomic deformation of the penis; with known cardiac disease (effects of sexual activity need to be evaluated); concomitant use of protease inhibitors when used for pulmonary hypertension
Available Forms
Tablets—20 mg (Revatio); 25, 50, 100 mg (Viagra); single use vial for injection—10 mg/12.5 mL (Revatio)
Dosages
Adults
ED: 50 mg PO taken 1 hr before anticipated sexual activity; range, 25–100 mg PO. May be taken 30 min–4 hr before sexual activity. Limit use to once per day (Viagra). • Pulmonary arterial hypertension: 20 mg PO tid, at least 4–6 hr apart and without regard to food (Revatio); or 10 mg by IV bolus tid (Revatio).
Pediatric patients
Not intended for use in children.
Geriatric patients
For patients older than 65 yr, start with 25 mg PO when used for erectile dysfunction.
Patients with renal or hepatic impairment
Patients with hepatic impairment or CrCl less than 30 mL/min may have increased serum levels; start dose at 25 mg PO (Viagra); no dosage adjustment needed for Revatio.
Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
