Sildenafil us label
viagra generico contraindicaciones sildenafil us label
3 to 0. 4 mg dose of nitroglycerin (tablet or spray) should be administered sublingually, and repeated every 5 minutes up to three times or until symptoms resolve. Standing enhances venous pooling and may contribute to hypotension, dizziness, or lightheadedness. Sublingual nitroglycerin may be used to prevent effort- or exertion-induced angina. In this case, the patient should use sublingual nitroglycerin 2 to 5 minutes prior to an activity known to cause angina, with the effects persisting for approximately 30 minutes. Isosorbide dinitrate, also available in sublingual form, has a longer half-life with antianginal effects lasting up to 2 hours. The use of short-acting nitrates alone, without concomitant long-acting antianginal therapy, may be acceptable for patients who experience angina symptoms once every few days. However, for patients with more frequent attacks, other antianginal therapies are recommended. The use of nitrates within 24 to 48 hours of a phosphodiesterase type 5 inhibitor (eg, sildenafil, vardenafil, and tadalafil), commonly prescribed for erectile dysfunction, is contraindicated. Phosphodiesterase degrades cgmp, which is responsible for the vasodilatory effects of nitrates. Concomitant use of nitrates and phosphodiesterase type 5 inhibitors enhances cgmp-mediated vasodilation and can result in serious hypotension, decreased coronary perfusion, and even death. All patients with ihd should be prescribed sublingual nitroglycerin and educated regarding its use. Points to emphasize when counseling a patient on sublingual nitroglycerin use include. •• the seated position is generally preferred when using nitroglycerin because the drug may cause dizziness. •• call 911 if symptoms are unimproved or worsen 5 minutes after the first dose.