Levitra (vardenafil) should be used only by people to whom it was prescribed. It is intended for the treatment of erectile dysfunction that can be described as the inability get an erection hard enough to have sex. Levitra is a relatively safe medicine and can therefore be taken by patients in spite of their age and health condition. Nevertheless, your health conditions should be reported to the doctor before asking him for a prescription, as a dose adjustment may be required. Do not take any prescription or over-the-counter drugs, as these may affect the efficiency of Levitra or cause dangerous interference. You should be especially careful with nitrate-based drugs, as their combination with Viagra can sometimes be fatal. Nitrates come sin a variety of forms, such as tablets, sublingual tablets, patches, ointments, pastes, sprays and so on. If you are not absolutely sure your drug is not a nitrate, please consult your health care provider for additional information. Make sure your health care provider knows about any other medications you are taking at the moment, including but not limited to danazol, antifungals, high blood pressure medications, paroxetine, disopyramide, clarithromycin, amiodarone, drugs for irregular heartbeat treatment, sertraline, phenobarbital, quinidine, cimetidine, phenytoin, isoniazid, nefazodone, rifabutin, erythromycin, HIV protease inhibitors, alpha blockers, aprepitant, carbamazepine, efavirenz, rifampin, dexamethasone, metronidazole, cyclosporine, other erectile dysfunction drugs, or fluoxetine.