Viagra used to treat erectile dysfunction.
CONTRAINDICATIONS
Consistent with its known effects on the nitric oxide / cGMP path, Viagra has shown potential hypotensive effects of nitrates and its administration to patients using organic nitrates, either regularly and / or intermittently, in any form, by rioja therefore, is contraindicated.
After the patients had Viagra, it is unknown when nitrates, if necessary, can be managed. Based on the pharmacokinetic profiles of a single 100 mg oral dose to normal healthy volunteers, plasma levels of sildenafil at 24 hours after a dose of 2 ng / ml (compared to peak plasma levels of approximately 440 ng / ml). In the following patients: age> 65 years, liver disorders (eg, cirrhosis), severe kidney damage (eg, creatinine clearance <30 ml / min) and concomitant use of potent cytochrome P450 3A4 inhibitors (erythromycin ), plasma levels of sildenafil at 24 hours after the dose were 3 to 8 times higher than in healthy volunteers. Although plasma levels of sildenafil at 24 hours after the dose is significantly below the maximum concentration, it is unknown whether nitrates can be safely coadministered at this time.
Viagra is contraindicated in patients with known hypersensitivity to any component of the tablets.
WARNINGS
There is a potential risk to the heart of sexual activity in patients with preexisting cardiovascular disease. Therefore, for the treatment of erectile dysfunction, including Viagra should not be used in general, men for whom sexual activity is not desirable, because their major cardiovascular condition.
Viagra has systemic vasodilatory properties, resulting in a temporary reduction in blood pressure in supine healthy volunteers (mean maximum reduction of 8.4/5.5 mm Hg). While this usually has little consequence in most patients, prior to the appointment of Viagra, doctors should carefully consider whether their patients with cardiovascular disease, can adversely affect such vasodilatory effects, especially in combination with sexual activity.
Patients with these conditions may be particularly sensitive to the actions of vasodilators including Viagra - those with obstruction of left ventricular outflow (eg, aortic stenosis, idiopathic hypertrophic subaortic stenosis) and those who are severely affected autonomic control blood pressure.
There are no controlled clinical data on safety and efficacy of Viagra in the following groups, if any, should be done with caution.
• Patients who have suffered a heart attack, stroke, or life-threatening arrhythmia in the past 6 months;
• Patients with hypotension rest (AD 170/110);
• In patients with heart failure and coronary artery disease causing unstable angina;
• Patients with retinitis pigmentosa (a minority of these patients have genetic diseases retinal phosphodiesterases).
Prolonged erection over 4 hours and priapism (painful for more than 6 hours in duration) have been reported infrequently since market approval of Viagra. For the installation, which is already more than 4 hours, the patient should seek immediate medical attention. If priapism is not treated immediately, damage to the penile tissues and permanent loss of potency may result.
Concomitant administration of protease inhibitor ritonavir increases serum concentrations of sildenafil (11 times the AUC). If Viagra is assigned to patients taking ritonavir, caution should be used. These subjects exposed to high systemic levels of Sildenafil limited. Visual disturbances occurred more commonly at higher levels of sildenafil effects. Reduction of blood pressure, syncope, and prolonged erection were reported in some healthy volunteers exposed to high doses of sildenafil (200-800 mg). To reduce the risk of adverse reactions in patients taking ritonavir, a decrease Sildenafil dose.
