III. Pharmacokinetics
IV. Dosing
- Start 50 mg PO 1 hour before intercourse
- Do not take more than once per day
- Most insurance limits to 6 per month
- Indications to start with half dosing (25 mg)
- Age over 65 years
- Hepatic Impairment
- Renal Impairment
- Consider crushing tablet and placing under Tongue
- May increase onset of action to 15 minutes
- May also increase absorption
- Consider lowering dose
V. Cost
- Wholesale: $7 per pill
VI. Contraindications
- See Phosphodiesterase Inhibitors (PDE5 Inhibitors)
- Men using nitrates (causes profound Hypotension)
- Men using alpha blockers (e.g. Hytrin for BPH)
VII. Mechanism
VIII. Drug Interactions
- See Phosphodiesterase Inhibitors (PDE5 Inhibitors)
- Profound Vasodilitation and Hypotension
- Nitroglycerin (Avoid within 24 hours of Sildenafil)
- Alpha blockers (e.g. Prazosin, Tamsulosin)
- Use with PDE5 Inhibitors only with caution when on these agents
- Cytochrome P3A4 related interactions (Cimetidine, systemic Antifungals, Protease Inhibitors and Macrolides
IX. Adverse Effects: Viagra (but most apply to the PDE5 Inhibitors as a whole)
- See Phosphodiesterase Inhibitors (PDE5 Inhibitors)
- Hypotensive effect for men on Nitrates (Avoid)
-
Vision effects
- Photophobia (transient, common)
- Color Visiion Changes (e.g. blue-green tint, which is common and transient)
- Serious Vision changes (occur in up to 16 in 10,000 patients per year)
- Sensorineural Hearing Loss
- Mild Headache
Images: Related links to external sites (from Bing)
Related Studies
| viagra (on 10/19/2022 at Medicaid.Gov Survey of pharmacy drug pricing) | ||
| VIAGRA 100 MG TABLET | Generic | $0.25 each |
| sildenafil (on 12/21/2022 at Medicaid.Gov Survey of pharmacy drug pricing) | ||
| SILDENAFIL 100 MG TABLET | Generic | $0.25 each |
| SILDENAFIL 20 MG TABLET | Generic | $0.07 each |
| SILDENAFIL 25 MG TABLET | Generic | $0.16 each |
| SILDENAFIL 50 MG TABLET | Generic | $0.22 each |