Sildenafil citrate, tadalafil and vardenafil hydrochloride are contraindicated in patients with a known hypersensitivity to any organic nitrates (oral, sublingual, transdermal or by inhalation) due to the risk of developing potentially life-threatening hypotension. Concomitant use of PDE-5 inhibitors is contraindicated with HIV protease inhihibitors (indinavir, ritinovir, saquinavir) as well as ketoconazole, itraconazole, cimetidine and erythromycin, because these drugs are potent inhibitors of cytochrome P450 3A4 and can raise the plasma levels of PDE-5 inhibitors. Coadministration of PDE-5 inhibitors to patients taking alpha-adrenergic blockers such as alfluzocin or tamsulosin may lead to symptomatic postural hypotension, including dizziness and lighheadedness in some individuals.
If you have symptoms of ED, it’s important to check with your doctor before trying any treatments on your own. This is because ED can be a sign of other health problems. For instance, heart disease or high cholesterol could cause ED symptoms. With a diagnosis, your doctor could recommend a number of steps that would likely improve both your heart health and your ED. These steps include lowering your cholesterol, reducing your weight, or taking medications to unclog your blood vessels.