The Following Factors are Associated with Increased Plasma Levels of Sildenafil:
Age >65 (40% increase in AUC), hepatic impairment (e.g., cirrhosis, 80%), severe renal impairment (creatinine clearance <30 ml/min, 100%), and concomitant use of potent cytochrome P450 3A4 inhibitors (erythromycin, ketoconazole, itraconazole, 200%, saquinavir 210%). Since higher plasma levels may increase both the efficacy and incidence of adverse events, a starting dose of 25 mg should be considered in these patients.
Given the extent of the interaction with patients receiving concomitant therapy with ritonavir, it is recommended not to exceed a maximum single dose of 25 mg of sildenafil citrate in a 48 hour period.
Sildenafil citrate was shown to potentiate the hypotensive effects of nitrates and its administration in patients who use nitric oxide donors or nitrates in any form is therefore contraindicated.
Branded Viagra is supplied as blue, film-coated, rounded-diamond-shaped tablets containing sildenafil citrate equivalent to the nominally indicated amount of sildenafil as follows: 25 mg: Imprinted VGR25 on obverse side, PFIZER on reverse. 50 mg: Imprinted VGR50 on obverse side, PFIZER on reverse. 100 mg: Imprinted VGR100 on obverse side, PFIZER on reverse.
Generic forms of Sildenafil such as CAVERTA also come in 25mg, 50mg and 100mg doses though their appearances may vary.
Cialis will be available also as oral tablets in 10mg and 20mg strengths.
Recommended Storage: Store at controlled room temperature, 15-30°C (59-86°F)