Source: QJM  |  Posted 11 years ago

The combined alpha-beta antagonist carvedilol induces a chronic reduction of sexual activity whereas valsartan, an angiotensin II antagonist, not only does not significantly reduce sexual activity but may even increase it.

This is the chief finding of a double-blind cross-over study by researchers at the University of Pavia, Italy. They compared the effect of antihypertensive treatment with the two agents on the sexual activity of previously untreated hypertensive men.

They enrolled 160 newly diagnosed hypertensive men aged 40 to 49 years, all married and without any previous sexual dysfunction.

After four weeks on placebo, the patients were divided into two groups. In the first, 120 were randomised to receive carvedilol 50 mg once daily or valsartan 80 mg once daily for 16 weeks. This period was followed by another four-week placebo period, followed by the alternative regimen for a further 16 weeks.

In the second group, 40 patients received placebo according to a single-blind design for 16 weeks.

At the screening visit and every four weeks thereafter, blood pressure was evaluated and patients completed questionnaires about their sexual activity.

Both drugs lowered blood pressure significantly, normalisation being 48 percent with valsartan and 45 percent with carvedilol. Likewise, during the first month of therapy, sexual activity (frequency of sexual intercourse) declined with both drugs as compared with baseline.

That decrease, however, was statistically significant only with carvedilol. Frequency of intercourse fell from 8.2 to 4.4 occasions. With valsartan, the decline, from 8.3 to 6.6, was not statistically significant.

Moreover, as treatment continued beyond the first four weeks, sexual activity declined still further with carvedilol to 3.7 occasions per month but rose with valsartan, to 10.2. These findings were confirmed by the cross-over data.

Erectile dysfunction was a complaint of 15 patients treated with carvedilol (13.5 percent) but only one patient given valsartan (0.9 percent), as well as one patient in the placebo group.