Sildenafil Citrate
Generic Details
Generic Name
Sildenafil Citrate
Other Names
- Viagra
- Revatio
Drug Class
- Phosphodiesterase type 5 inhibitor
Chemical Formula
C22H30N6O4S
Molecular Weight
474.576 g/mol
Mechanism of Action
- Inhibition of cGMP-specific phosphodiesterase type 5 enzyme
Indications
- Erectile dysfunction
- Pulmonary arterial hypertension
Common Dosage Forms
- Tablet
- Oral suspension
Typical Dosage
- 25-100 mg once daily for erectile dysfunction
- 20 mg three times a day for pulmonary arterial hypertension
Pediatric Dosage
- Not established
Geriatric Dosage
- Dose adjustment may be needed
Side Effects
- Headache
- Flushing
- Dyspepsia
- Vision changes
- Hearing loss
- Hypotension
Contraindications
- Concomitant use with nitrates
- Severe hepatic impairment
- Hypersensitivity to sildenafil
Pregnancy Category
- Category B
Lactation Safety
- Not recommended
Drug Interactions
- Nitrates
- Alpha-blockers
- CYP3A4 inhibitors
Overdose Symptoms
- Hypotension
- Priapism
Antidote for Overdose
- Symptomatic and supportive treatment
Storage Conditions
- Store at room temperature away from moisture and heat
Pharmacokinetics
- Absorption: Rapidly absorbed after oral administration
- Distribution: Protein binding: 96%
- Metabolism: Primarily hepatic (CYP3A4)
- Excretion: Renal (80%) and fecal (13%)
Precautions
- Cardiovascular disease
- Prolonged erection
- Bleeding disorders
Warnings
- Potential for sudden vision loss
- Priapism risk