Cialis - Potent Weekend Drug

Nov. 25, 2003 -- Cialis, a drug for male impotence, was approved by the US Food and Drug Administration last week. Cialis joins sildenafil (Viagra), approved by the FDA in 1998, and vardenafil (Levitra), approved earlier this year, as drugs for erectile dysfunction. The effect of Cialis can last 24 to 36 hours, several times longer than Viagra or Levitra. "In France, it's called 'le weekend' drug," according to the drugmaker.

Our Thoughts: The FDA announcement of Cialis follows. Whenever possible, we prefer to provide you with the FDA announcement of a new drug rather than a rewrite of it which is often selective and biased.

Note that, if the effects of a drug are longer lasting, so usually are the dangers and side effects longer lasting.

For additional information, please see the following areas:

Barbara K. Hecht, Ph.D.
Frederick Hecht, M.D.
Medical Editors,

FDA Approves Third Drug To Treat Erectile Dysfunction

The Food and Drug Administration (FDA) today approved Cialis® (tadalafil), an oral medication to treat erectile dysfunction (ED, or impotence) in men. This is the third oral product approved for this condition. This drug is different than currently approved products for ED in that it stays in the body longer.

Erectile dysfunction (ED) affects millions of men in the United States. Cialis acts by relaxing muscles in the penis and blood vessels, allowing increased blood flow into the penis, which produces an erection.

Cialis was evaluated in randomized, placebo-controlled trials involving more than 4,000 men with erectile dysfunction. In two of these trials, men had ED 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 that erection was maintained to allow completion of intercourse. In all of these trials, Cialis improved patients' ability to achieve and maintain a penile erection. In other studies, sexual activity was improved in some patients at 30 minutes after taking a dose; additional studies demonstrated improvements for up to 36 hours after taking Cialis when compared to placebo.

The recommended starting dose for most patients is 10 mg taken prior to anticipated sexual activity. A higher dose of 20mg is available for patients whose response to the 10mg dose is not adequate. A lower dose (5 mg) is also available and may be necessary for patients taking other medicines or having medical conditions that may decrease the body's ability to metabolize tadalafil. Cialis should not be used more than once per day.

Cialis should not be used with nitrates (such as nitroglycerin tablets or patches) or with an alpha blocker other than FLOMAX 0.4mg daily (alpha blockers are medicines used to treat benign prostatic hyperplasia and high blood pressure) because the combination may significantly lower blood pressure and lead to fainting or even death in some men.

Because some drugs affect the metabolism of Cialis, patients should inform their doctors that they are taking Cialis. For example, patients taking ketoconazole or ritonoavir should not take more than a 10mg dose of Cialis once every 72 hours.

Also, in patients with moderately or severely decreased kidney function, the starting dose is 5mg taken once daily. In this group, the dose may be increased to 10mg taken once every 48 hours. In patients with mild or moderate liver impairment, the maximum dose of Cialis is 10mg.

In most patients, after taking a single dose of Cialis, some of the drug will remain in the body for more than 2 days. In those with decreased kidney function, impairment of the liver, or those taking certain medications (e.g. ketoconazole or ritonavir) tadalafil can remain in the body longer.