A second oral medication to treat impotence in men (erectile dysfunction) has been approved by the FDA. The drug, Levitra (vardenafil) acts by relaxing blood vessels and muscles in the penis, allowing increased blood flow into the penis to produce an erection.
Erectile dysfunction affects millions of men in the United States.
Levitra was evaluated in randomized, placebo-controlled trials involving more than 2,000 men with erectile dysfunction. In two of the trials, men had erectile dysfunction associated with diabetes mellitus or following radical prostatectomy for prostate cancer.
The drug's effectiveness was assessed using a sexual function questionnaire. In addition, patients were asked to report if they were able to achieve an erection adequate for intercourse and whether the erection was maintained to allow completion of intercourse. In all of the trials, Levitra improved patients' ability to achieve and maintain a penile erection.
The recommended dose is 10 milligrams taken 1 hour before sexual activity. A higher dose of 20 milligrams is available for patients whose response to the 10-milligram dose is not adequate. Two lower doses (2.5 mg and 5 mg) are also available and may be necessary for patients who are taking other medicines or have medical conditions that may decrease the body's ability to metabolize vardenafil. Levitra should not be used more than once a day.
Levitra should not be used with nitrates (such as nitroglycerin tablets or patches) or with alpha-blockers (medicines used to treat benign prostatic hyperplasia and/or high blood pressure such as tamsulosin, terazosin, doxazosin, and alfuzosin) because the combination may significantly lower blood pressure and lead to fainting in some men. Currently there is no information available to support the safety of even the lower doses of Levitra taken together with alpha-blockers. In addition, Levitra should not be used in patients who have a rare heart condition known as "prolongation of the QT interval" because of the possibility of producing abnormal heart rhythm.
Because some drugs may affect the metabolism of Levitra, patients should inform their doctors that they are taking Levitra and they should not begin taking new medicines without informing their doctor. For example, patients taking erythromycin should not take more than a 5-milligram dose of Levitra. The maximum recommended dose for patients who are taking ritonavir is 2.5 milligrams of Levitra once every 72 hours.
Levitra should not be taken by men in whom sexual activity is inadvisable because of their underlying cardiovascular status (heart condition). Patients should inform their doctor about any heart problems they have experienced before taking Levitra.
Levitra is not recommended in patients who have suffered a heart attack or stroke within the last six months, or patients who have significantly low blood pressure, uncontrolled high blood pressure, unstable angina, severe liver impairment, end-stage renal disease requiring dialysis, or retinitis pigmentosa (an eye disorder).
The most common side effects reported in clinical trials included headache, flushing, rhinitis, and indigestion. Dizziness was reported in about 2 percent of patients. A small number of patients taking Levitra also reported abnormal vision.
Levitra is manufactured by Bayer Corporation in Germany and will be distributed by GlaxoSmithKline of Research Triangle Park, N.C. The drug is currently available in Europe.
COPYRIGHT 2003 U.S. Government Printing Office
COPYRIGHT 2004 Gale Group