Nasal Spray May Provide New Answer for Erectile Dysfunction
Administering a drug through the nose is not a novel idea, says Wessells, who points out that this route is already used for Imitrex, a drug used to treat migraine headaches. He explains that drugs are quickly absorbed through the linings of the nasal passages and thus may enter the bloodstream even faster than drugs administered as pills.
While PT-141 is a central nervous system stimulator, Viagra works by helping to relax smooth muscle cells, which increases the blood flow to the penis and thus makes it easier to achieve and maintain an erection. Men are advised to take Viagra an hour before attempting sexual relations, and the drug's effect lasts for about 4 hours.
A few years ago, while teaching at the University of Arizona, Wessells conducted clinical studies of a "molecule that is similar to PT-141.That drug was administered with a subcutaneous injection," he says. "We studied 20 subjects with 39 administrations and found no serious side effects and no cardiovascular side effects." Some men who have heart disease can't take Viagra because it adversely enhances the affect of common heart drugs called nitrates.
Last year there was a great deal of excitement generated by another Viagra alternative called Uprima. That drug was recommended for FDA approval last April, but just as the FDA was poised to issue a final decision, the manufacturer, TAP Pharmaceuticals, withdrew the new drug application. Several vocal opponents of the drug said it caused fainting spells, which in one case caused a car accident when a man passed out at the wheel. The drug also causes nausea, and men were advised to avoid eating when taking the drug, which is given as a lozenge.
Martha McKennitt, a spokeswoman for TAP Pharmaceuticals, which is a joint venture of Abbott Laboratories of Abbott Park, Ill., and Takeda Chemical Industries of Japan, tells WebMD that the company "plans to meet this quarter with the FDA to determine when to resume the approval process" for Uprima.
"There is some overlap of the side effects profile between drugs like PT-141 and [Uprima], at least as far as nausea," says Wessells. But he says that the effects do not appear as pronounced.