BETHESDA, Md. - A tablet called Uprima may soon be cutting into Viagra's impotence drug market, thanks to government advisers' recommendation Monday that the tablet be allowed to be sold despite some worrisome side effects.
Uprima helped some men regain erections strong enough for sexual intercourse, said a Food and Drug Administration advisory panel. And because many of the nation's estimated 30 million impotent men are not helped by today's medications, the panel voted 9-3 Monday to urge the FDA to allow Uprima be made available as long as patients and their doctors get strong warnings.
But one in 30 men who tested the optimal dose of Uprima fainted or suffered seriously low blood pressure, and a few fell and hit their heads, the FDA said. In one case, a man crashed his car into a fence.
The side effects has raised concerns among some physicians.
''There will be some people who will probably lose their lives because they pass out at the top of stairs or are operating a car'' when they faint, warned FDA adviser and Philadelphia cardiologist Dr. Peter Kowey.
''This drug is clearly going to kill some people,'' agreed Dr. Robert Califf of Duke University, saying most at risk are men with serious heart disease who take other medicines that lower blood pressure.
Still, both Kowey and Califf joined the panel majority in the 9-3 vote Monday.
The FDA is not bound by its advisers' decisions but typically follows them.
Uprima manufacturer TAP Pharmaceuticals said men desperately need alternative treatments.
Viagra became a huge seller when it hit the market in 1998 as the only oral impotence treatment - and Viagra has killed some men. Viagra's big risk is a deadly interaction when taken by men using nitrate-containing heart medicine.
TAP said in studies of 3,000 patients, most that lasted a month, no one died or had heart attacks. Still, FDA's advisers couldn't say Uprima would be any safer for nitrate-using heart patients.
But Uprima does work very differently than Viagra. Viagra increases blood flow in the penis. Uprima, in contrast, works in the brain.
''Your brain is your most important sexual organ,'' said Dr. Timothy Fagan of the University of Arizona, who helped test the drug for TAP, a joint venture between Abbott Laboratories and Takeda Pharmaceuticals.
Uprima is not an aphrodisiac, Fagan said. It seems to increase levels of dopamine - an important neurochemical that sends messages between cells - in a brain region thought important for causing erections.
Also unlike Viagra, Uprima is not swallowed - the tablet is dissolved under the tongue, where it seeps into the bloodstream through mouth tissue.
In studies, men who took 2 milligrams of Uprima had an erection capable of intercourse about 47 percent of the time. Success increased to 56 percent when men took 4 mg of Uprima.
But a sugar pill worked for these same men a third of the time, the FDA cautioned.
Taking doses of Uprima higher than 4 mg was a little more effective, but caused so many more side effects that TAP Pharmaceuticals decided not to sell the higher doses.
But even the optimal 4-mg dose caused either low blood pressure or a brief fainting spell in one of every 30 men, FDA officials said.
In addition, about 5 percent of men suffered nausea, vomiting, dizziness, sweating or sleepiness. Those side effects are not surprising considering Uprima is a new formulation of a 130-year-old chemical called apomorphine once widely used, at higher doses, to induce vomiting.
But the most serious side effects included:
-A 33-year-old man took 4 mg of Uprima in his doctor's office but, while driving home 30 minutes later, became nauseous, sweaty, tired and flushed. He attempted to stop his car but fainted and crashed into a fence.
-A 56-year-old who took 4 mg of Uprima fainted for 15 to 20 minutes and was hospitalized with severely low blood pressure.
-A 42-year-old took a little higher dose, 5 mg, and passed out in his doctor's office. Falling, he hit his head and fractured his skull.
TAP Pharmaceuticals says fainting should be preventible. Some 85 percent of men who faint have nausea, vomiting or sweating first, signs they should sit or lie down, Fagan said. Blood pressure is usually higher while lying down than standing. Plus, if Uprima is sold, most men will take it at home and then fairly quickly lie down - Uprima's instructions say to take it about half an hour before sex.
But the FDA's advisers also want men warned that:
-More than one or two alcoholic drinks may increase Uprima's side effects.
-Uprima doesn't help all types of impotence, and wasn't even studied for its effectiveness against the most severe forms.
On the Net:
FDA's pre-meeting summary of Uprima: http://www.fda.gov/ohrms/dockets/ac/00/transcripts/3602b1c.pdf