SILDENAFIL

brands

Class

• Phosphodiesterase-5 inhibitor (PDE-5 inhibitor)

SILDENAFIL commonly prescribed for

(Bold for FDA approved)

How SILDENAFIL works

• PDE-5 is responsible for degradation of cyclic guanosine monophosphate (cGMP); cGMP produces smooth muscle relaxation in the corpus cavernosum and allows inflow of blood

• Inhibition of PDE-5 causes increased levels of cGMP in the corpus cavernosum, resulting in smooth muscle relaxation and inflow of blood to the corpus cavernosum

• Sildenafil has no direct relaxant effects on isolated human corpus cavernosum, and at recommended doses has no effect in the absence of sexual stimulation

How long until SILDENAFIL works

• Maximum observed plasma concentrations are reached within 30–120 minutes (median 60 minutes) of oral dosing

Notable Side Effects

• Headache

• Flushing

• Dyspepsia (indigestion, diarrhea)

Life Threatening Side Effects

• Sudden severe loss of vision and/or blurred vision

• Sudden decrease or loss of hearing, ringing in ears

• Erection that is painful or lasts longer than 4 hours

weight gain

unusual

sedation

unusual

What to do about SILDENAFIL side effects

• Reduce dose to 25 mg

usual dosage range

• Erectile dysfunction: 25–100 mg as needed, approximately 1 hour before sexual activity (Viagra)

• Pulmonary arterial hypertension (tablet and oral suspension): 5 mg or 20 mg 3 times a day, 4–6 hours apart

Dosage Forms

• Tablet 25 mg, 50 mg, 100 mg

• Injectable solution 10 mg/12.5 mL

long term use

• Safe

habit forming

• No

Renal Impairment

• No adjustment for mild to moderate impairment

• For patients with severe impairment, consider a starting dose of 25 mg

Hepatic Impairment

• Consider a starting dose of 25 mg

Cardiac Impairment

• Elicits vasodilatory properties, resulting in mild and transient decreases in blood pressure

• Treatment for erectile dysfunction generally should not be instituted in men for whom sexual activity is inadvisable because of their underlying cardiovascular status

• There are no controlled clinical data on the safety or efficacy of sildenafil in patients who have suffered a myocardial infarction, stroke, or life-threatening arrhythmia within the last 6 months; have resting hypotension (BP <90/50 mmHg) or hypertension (BP >170/110 mmHg); or have cardiac failure or coronary artery disease causing unstable angina; use only with caution in these patients

• Use with caution in patients with left ventricular outflow obstruction (e.g., aortic stenosis, idiopathic hypertrophic subaortic stenosis) and those with severely impaired autonomic control of blood pressure

Elderly

• Some patients may tolerate lower doses better

• Consider a starting dose of 25 mg

Children and Adolescents

• Not recommended for use in pediatric patients

• Safety and efficacy have not been established

Pregnancy

• Viagra is not indicated for use in women

• Controlled studies have not been conducted in pregnant women.

• Animal studies did not show teratogenicity or adverse developmental outcomes when administered during organogensis at doses up to 16 and 32 times the maximum recommended human dose

Breast Feeding

• Some drug is found in mother’s breast milk