Viagra (sildenafil) Alcohol, Food & Lifestyle Interactions

There are 2 food and lifestyle interactions with Viagra (sildenafil) which include:

GENERALLY AVOID: Alcohol may potentiate the hypotensive effects of phosphodiesterase-5 (PDE5) inhibitors, and vice versa, as both are mild systemic vasodilators. In clinical pharmacology studies using tadalafil, more subjects administered alcohol at a dose of 0.7 g/kg (consumed within 10 minutes; equivalent to approximately 6 ounces of 80-proof vodka in an 80-kg male) in combination with tadalafil 10 or 20 mg single doses had clinically significant decreases in blood pressure than with alcohol alone. There were reports of postural dizziness, and orthostatic hypotension was observed in some. When tadalafil 20 mg was administered with alcohol at a lower dose of 0.6 g/kg (equivalent to approximately 4 ounces of 80-proof vodka), orthostatic hypotension was not observed, dizziness occurred with similar frequency relative to alcohol alone, and the hypotensive effects of alcohol were not potentiated. Neither tadalafil nor alcohol affected the plasma concentrations of the other. Sildenafil 50 mg and vardenafil 20 mg reportedly did not potentiate the hypotensive effect of alcohol in healthy volunteers with mean maximum blood alcohol levels of 0.08% and in healthy volunteers administered alcohol at a dose of 0.5 g/kg, respectively.

MANAGEMENT: Based on known pharmacology of the drugs, patients taking PDE5 inhibitors should probably avoid consuming large amounts of alcohol, which may increase the potential for orthostatic signs and symptoms, including increase in heart rate, decrease in standing blood pressure, dizziness, and headache.

GENERALLY AVOID: Coadministration with grapefruit juice may slightly increase the oral bioavailability and delay the onset of action of sildenafil. The proposed mechanism is inhibition of CYP450 3A4-mediated first-pass metabolism in the gut wall by certain compounds present in grapefruits. In a randomized, crossover study with 24 healthy male volunteers, ingestion of 250 mL of grapefruit juice one hour before and concurrently with a 50 mg dose of sildenafil increased the mean area under the plasma concentration-time curve (AUC) of sildenafil and its pharmacologically active N-desmethyl metabolite by 23% and 24%, respectively, compared to water. Peak plasma concentrations (Cmax) were unaltered, but the time to reach sildenafil Cmax was prolonged by 0.25 hour. The observed increase in sildenafil bioavailability is unlikely to be of clinical significance in most individuals. However, pharmacokinetic interactions involving grapefruit juice are often subject to a high degree of interpatient variability and may be significant in the occasional susceptible patient. Indeed, one subject in the study had a 2.6-fold increase in sildenafil concentrations.

MANAGEMENT: It may be advisable to avoid administration of sildenafil with grapefruit juice to prevent potential toxicity and delay in onset of action.

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Viagra (sildenafil) drug Interactions

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Viagra (sildenafil) disease Interactions

There are 5 disease interactions with Viagra (sildenafil) which include:

Cardiovascular Disease Liver Disease Renal Dysfunction

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