Nitrates are also found in some recreational drugs such as amyl nitrate or nitrite ("poppers"). The cGMP in turn triggers smooth muscle relaxation, allowing increased blood flow into the penis, resulting in erection. Levitra was dosed without regard to meals on an as needed basis in men with ED, many of whom had multiple other medical conditions. This metabolite shows a phosphodiesterase selectivity profile similar to that of vardenafil and an The total body clearance of vardenafil is 56 L/h, and the terminal half-life of vardenafil and its primary metabolite (M1) is approximately 4-5 hours. The tissue concentration of cGMP is regulated by both the rates of synthesis and degradation via phosphodiesterases (PDEs). The dose may be increased to a maximum recommended dose of 20 mg or decreased to 5 mg based on efficacy and side effects. You can ask your doctor or pharmacist for information about Levitra that is written for health professionals.For more information you can also visit www.Levitra.com, or call 1-888-825-5249.This Patient Information has been approved by the U.S. Food and Drug Administration.Norvir (ritonavir) is a trademark of Abbott LaboratoriesLevitra is a registered trademark of Bayer Pharma AG and is used under license by GlaxoSmithKline.The easiest way to lookup drug information, identify pills, check interactions and set up your own personal medication records. Levitra has not been administered to patients with bleeding disorders or significant active peptic ulceration. The majority of these subjects experienced reversible back pain/myalgia and/or “abnormal vision.” Single doses up to 80 mg vardenafil and multiple doses up to 40 mg vardenafil administered once daily over 4 weeks were tolerated without producing serious adverse side effects.When 40 mg of vardenafil was administered twice daily, cases of severe back pain were observed. Physicians should also discuss with patients the increased risk of NAION in individuals who have already experienced NAION in one eye. The plasma concentration of M1 is approximately 26% that of the parent compound. Do not use Levitra in patients with severe (Child-Pugh C) hepatic impairment. There may be new information. Over 2200 patients were treated for 6 months or longer and 880 patients were treated for at least 1 year.In placebo-controlled clinical trials, the discontinuation rate due to adverse events was 3.4% for Levitra compared to 1.1% for placebo.When Levitra was taken as recommended in placebo-controlled clinical trials, the following adverse reactions were reported (see Table 1).Back pain was reported in 2.0% of patients treated with Levitra and 1.7% of patients on placebo.Placebo-controlled trials suggested a dose effect in the incidence of some adverse reactions (headache, flushing, dyspepsia, nausea, and rhinitis) over the 5 mg, 10 mg, and 20 mg doses of Levitra.In the placebo-controlled clinical trials for Levitra film-coated tablets and vardenafil orally disintegrating tablets, the discontinuation rate due to adverse events was 1.9% for vardenafil compared to 0.8% for placebo.The following section identifies additional, less frequent adverse reactions (<2%) reported during the clinical development of Levitra film-coated tablets and vardenafil orally disintegrating tablets. The major circulating metabolite, M1, results from desethylation at the piperazine moiety of vardenafil. There is no clinical evidence of any additive prolongation of the bleeding time when vardenafil is administered with aspirin. Once a man has completed sexual activity, blood flow to his penis decreases, and his erection goes away.Talk to your doctor to decide if Levitra is right for you.Levitra has been shown to be effective in men over the age of 18 years who have erectile dysfunction, including men with diabetes or who have undergone prostatectomy.Take 1 Levitra tablet about 1 hour (60 minutes) before sexual activity. Patients should be advised to contact their healthcare provider for dose modification if they are not satisfied with the quality of their sexual performance with Levitra or in the case of an unwanted effect.Inform patients that there have been rare reports of prolonged erections greater than 4 hours and priapism (painful erections greater than 6 hours in duration) for Levitra and this class of compounds. It is not possible to determine whether these events are related directly to the PDE5 inhibitors, to other diseases or medications, to other factors, or to a combination of factors. Symptoms of hypotension were a cause for withdrawal in 2 subjects receiving terazosin and in 4 subjects receiving tamsulosin. For more information, ask your doctor or pharmacist.Call your doctor for medical advice about side effects. These events, which may be accompanied by tinnitus and dizziness, have been reported in temporal association to the intake of PDE5 inhibitors, including Levitra.