Sildenafil Disease Interactions
There are 5 disease interactions with sildenafil:
Due to the potential cardiac risk associated with sexual activity in patients with preexisting cardiovascular disease, treatment for erectile dysfunction is generally not recommended in men for whom sexual activity is inadvisable because of their cardiovascular status. With respect to sildenafil, physicians should also consider the vasodilatory effect of the drug and whether it may adversely affect patients with underlying cardio- and/or cerebrovascular conditions, in particular those who have suffered a myocardial infarction, stroke, or life-threatening arrhythmia within the last 6 months; those with resting hypotension (BP < 90/50) or hypertension (BP > 170/110); and those with unstable angina associated with cardiac failure or coronary artery disease. There are no controlled clinical data on the safety or efficacy of sildenafil in such patients. In healthy volunteers, sildenafil has been shown to produce a mean maximum decrease of 8.4/5.5 mm Hg in supine blood pressure. This decrease is unrelated to dose or plasma drug levels. Other adverse cardiovascular effects reported include angina pectoris, myocardial infarction, AV block, ventricular arrhythmia, tachycardia, palpitation, hypotension, postural hypotension, syncope, cerebral thrombosis, cerebrovascular hemorrhage, transient ischemic attack, cardiac arrest, heart failure, and hypertension. Many of these events occurred in patients with cardiovascular risk factors and during or shortly after sexual activity.
The plasma clearance of sildenafil may be decreased in patients with liver disease, resulting in drug accumulation. In volunteers with cirrhosis (Child-Pugh A and B), the peak plasma concentration (Cmax) increased by 47% and the area under the concentration-time curve (AUC) increased by 84% compared with age-matched volunteers without liver disease. Therapy with sildenafil should be administered cautiously in patients with significantly impaired hepatic function. A starting oral dose of 25 mg should be considered.
The plasma clearance of sildenafil may be decreased in patients with severe renal impairment, resulting in drug accumulation. In volunteers with creatinine clearance below 30 mL/min, the peak plasma concentration (Cmax) and area under the concentration-time curve (AUC) approximately doubled compared with age-matched volunteers without renal impairment. Therapy with sildenafil should be administered cautiously in patients with significantly impaired renal function. A starting oral dose of 25 mg should be considered.
Prolonged erection greater than 4 hours and priapism (painful erections greater than 6 hours) have been reported infrequently during postmarketing use of sildenafil. Priapism may result in penile tissue damage and permanent loss of potency if not treated promptly. Sildenafil should be used cautiously in patients with conditions that may predispose them to priapism such as sickle cell anemia, multiple myeloma, or leukemia. If an erection persists longer than 4 hours, the patient should seek immediate medical assistance.
The use of sildenafil, particularly at higher dosages or elevated plasma drug levels, may be associated with transient impairment of color discrimination (blue/green) and blue- or color-tinged vision. Sildenafil inhibits phosphodiesterase-6 (PDE6), which is involved in phototransduction in the retina. There are no controlled clinical data on the safety of sildenafil in patients with retinitis pigmentosa, a minority of whom may have genetic disorders of retinal phosphodiesterases. Therapy with sildenafil should be administered cautiously in such patients.
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sildenafil drug Interactions
There are 434 drug interactions with sildenafil
sildenafil alcohol/food Interactions
There are 2 alcohol/food interactions with sildenafil
Drug Interaction Classification
The classifications below are a general guideline only. It is difficult to determine the relevance of a particular drug interaction to any individual given the large number of variables.
|Major||Highly clinically significant. Avoid combinations; the risk of the interaction outweighs the benefit.|
|Moderate||Moderately clinically significant. Usually avoid combinations; use it only under special circumstances.|
|Minor||Minimally clinically significant. Minimize risk; assess risk and consider an alternative drug, take steps to circumvent the interaction risk and/or institute a monitoring plan.|
Do not stop taking any medications without consulting your healthcare provider.
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