Tadalafil Treats Erectile Dysfunction; Low Cardiovascular Risk

Laurie Barclay, MD

May 30, 2002

May 31, 2002 -- Tadalafil (Cialis), a selective phosphodiesterase type 5 inhibitor, treats erectile dysfunction (ED) with little adverse cardiovascular effect, according to new clinical data presented May 25 at the 97th annual meeting of the American Urological Association in Orlando, Florida.

"Cialis was statistically superior to placebo in enabling men with ED to have successful intercourse at 24 or 36 hours after taking the drug and showed a consistent effect at both time points," author Raymond Rosen, PhD, from Robert Wood Johnson Medical School in Piscataway, NJ, says in a news release. "The duration of effectiveness did not appear to influence the incidence or severity of side effects."

In a phase III, randomized, clinical study, 348 men with mild-to-severe ED received tadalafil 20 mg or placebo over an 8-week period. Patients were instructed to attempt intercourse on 2 occasions at 24 hours after dosing and on 2 occasions at 36 hours after dosing. Tadalafil was statistically superior to placebo in the percentage of successful sexual intercourse attempts at 24 and 36 hours ( P<.001), as well as in secondary outcome measures including penetration ability, satisfaction with hardness of erection, and overall satisfaction ( P<.001).

Treatment-related adverse effects reported by more than 5% of patients were headache, flushing, and dyspepsia. Less than 2% of patients in either group left the study because of adverse effects, and there were no treatment-related serious adverse events reported.

In a separate presentation, Robert A. Kloner, MD, PhD, from the University of Southern California, Los Angeles, summarized the overall cardiovascular profile of tadalafil based on data from several phase III pivotal clinical trials and other studies. These trials included men with a wide variety of stable cardiovascular conditions, such as hypertension treated with multiple medications.

"Overall, the incidence of cardiovascular events was not statistically significantly different from placebo," Kloner says. "These newly presented clinical safety data provide further information for the cardiovascular profile demonstrated in clinical trials for Cialis."

Compared with placebo, healthy patients taking tadalafil 20 mg had no statistically significant differences in standing blood pressure or heart rate. Across all clinical studies, which involved more than 4000 patients, incidence of myocardial infarction was similar in patients treated with tadalafil or placebo.

In large-scale phase III clinical trials involving 1328 men with ED, the overall incidence of cardiovascular adverse effects, including flushing, dizziness, hypertension, and syncope, was not statistically significantly different in the placebo- and tadalafil -treated groups.

Lilly ICOS LLC, a joint venture between ICOS Corporation and Eli Lilly and Company, is developing Cialis for the treatment of sexual dysfunction. Co-administration of a nitrate with tadalafil is likely to be contraindicated, because tadalafil relaxes vascular smooth muscle, which augments the hypotensive effects of nitrates.

AUA Annual Meeting. May 25, 2002.

Reviewed by Gary D. Vogin, MD


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