Therefore, PDE5 inhibitors, including VIAGRA, shouldbe used with caution in these patients and only when the anticipated benefitsoutweigh the risks. Co-administration of erythromycin, a moderate CYP3A4 inhibitor, resulted in 160% and 182% increases in sildenafil C and AUC, respectively. Co-administration of saquinavir, a strong CYP3A4 inhibitor, resulted in 140% and 210% increases in sildenafil C and AUC, respectively. Stronger CYP3A4 inhibitors such as ketoconazole or itraconazole could be expected to have greater effects than seen with saquinavir.

CLINICAL PHARMACOLOGY

However, in vitro studies withhuman platelets indicate that sildenafil potentiates the antiaggregatory effectof sodium nitroprusside (a nitric oxide donor). In addition, the combination of heparin and VIAGRA had an additive effect on bleeding time in the anesthetizedrabbit, but this interaction has not been studied in humans. VIAGRA has systemic vasodilatory properties and mayfurther lower blood pressure in patients taking antihypertensive medications.

have any other medical conditions

The maximum observed decrease in diastolic blood pressure was -17.2 mmHg when sildenafil was co-administered with alcohol versus -11.1 mmHg when alcohol was administered alone. There were no reports of postural dizziness or orthostatic hypotension. The maximum recommended dose of 100 mg sildenafil was not evaluated in this study [see DRUG INTERACTIONS]. VIAGRA was evaluated primarily at doses of 25 mg, 50 mg and 100 mg in 21 randomized, double-blind, BUY XANAX WITHOUT PRESCRITION placebo-controlled trials of up to 6 months in duration, using a variety of study designs (fixed dose, titration, parallel, crossover). VIAGRA was administered to more than 3,000 patients aged 19 to 87 years, with ED of various etiologies (organic, psychogenic, mixed) with a mean duration of 5 years.
Erectile dysfunction is a common condition that affects an estimated 30 to 50 million people in the United States. Discuss your health with your doctor to ensure that you are healthy enough for sex. If you experiencechest pain, dizziness, or nausea during sex, seek immediate medical help.

have low blood pressure, or high blood pressure that is not controlled

It is eliminated predominantly by hepatic metabolism (mainly CYP3A4) and is converted to an active metabolite with properties similar to the parent, sildenafil. Both sildenafil and the metabolite have terminal half lives of about 4 hours. There was no effect on sperm motility or morphology after single 100 mg oral doses of VIAGRA in healthy volunteers.
Alcohol combined with sildenafil may cause some adverse side effects like a sudden drop in BP. Give your health care provider a list of all the medicines, herbs, non-prescription drugs, or dietary supplements you use. Also tell them if you smoke, drink alcohol, or use illegal drugs.