Erectile Dysfunction; Next Step On Viagra/ Find Out Who Likes It Best
August 19, 1998
Impotence & Male Health Weekly Plus via NewsEdge Corporation : Doctors who first tested Viagra for government approval are checking now to see who benefits most from using the drug.
Doctors and government regulators are still convinced the drug is safe despite all the media attention to reports that several men have died after taking Viagra. But they say the next step is to find out if there are certain groups of men with erectile dysfunction who do better on Viagra than others.
They may also do more checking with partners of men who use Viagra to see if it works as well as patients claim it does.
"I think in certain subpopulations it may work better," said Dr. William Steers, University of Virginia who helped test the drug for Pfizer. He said he sees about 500 patients a year who have erectile dysfunction, with causes ranging from diabetes to prostate surgery to psychological problems.
"I am going to look at those groups and see how many are better (with Viagra)," Steers said in a telephone interview.
Dr. Irwin Goldstein, Boston University in Massachusetts is testing Viagra on women and plans tests to see if it can actually prevent impotence and sexual dysfunction in some men and women.
Viagra works by getting blood down to the sexual organs.
"In men who are impotent, a very common observation is one of the things they also lose is they don't wake up in the morning with erections," Goldstein said. Taking Viagra might restore that.
It might also keep sexual organs healthy and functioning in high-risk groups such as diabetics, he said. "You've heard of the expression, 'If you don't use it you ... lose it'."
But Steers said it is hard to tell precisely how well Viagra works as erectile dysfunction is judged subjectively.
"It makes it a challenging study," he said. "I think the bottom line on efficacy is how many patients renew prescriptions they pay out of pocket. If it didn't work they wouldn't keep paying money multiple times. "
And, by all accounts, they are. Market research firm IMS Health said 2.9 million Viagra prescriptions were filled in April, May and June 1998, with sales estimated at $259.5 million and forecast to reach $1 billion by March 1999.
The New England Journal of Medicine, which published the original research by Steers and a team of other experts around the country, said it would welcome a more detailed study.
"We don't yet have enough information about which men respond and which do not," Deputy Editor Dr. Robert Utiger said in a telephone interview. "One wonders with larger numbers of men if we [are] ... able to identify in advance those who benefit and those who do not."
Utiger and Steers said they would also look for details of additional side- effects as more and more men take the drug. But they are not overly upset by reports that some men have died.
The U.S. Food and Drug Administration (FDA) gives out death figures only after a specific Freedom of Information request but its latest figures showed 30 men were reported to have died after taking Viagra. The FDA said there is no evidence Viagra was the cause in any of the deaths but it and Pfizer are checking.
Steers said the number of deaths is not surprising.
"If you age-index it for how many medical problems the individuals have and you take out those who took it inappropriately with nitrates or nitroglycerin, I don't know of any huge disasters," he said.
Utiger also noted that Viagra is known to interact badly with heart medications containing nitrates.
"Were these in fact men who took the drug and took their nitroglycerin 10 minutes later and died 15 minutes later?" he asked. "Exactly what were the circumstances here? And will there be some kind of cumulative or late- appearing side-effects that have as yet been unrecognized?"
Utiger said he would welcome in any study confirmation from wives and other partners that Viagra actually works. "It would have been nice to have had some information from the partners.
I think it would be a very useful addition to the study."
Otherwise, he said, it is hard to confirm the drug's true effects. "(You could) do something in a research setting in a hospital or a clinic ... where you could make some measurements of the rigidity or something and obviously that's objective evidence, but that's also not the real world."
Steers agreed. "Unfortunately, when it comes to erectile dysfunction, you like to have a blood sugar, blood pressure, some number," he said. Simply asking a man how his erection is makes objective measurement difficult, but Steers said his team did its best to get objective numbers, taking some laboratory measurements and also asking wives and other sex partners.
"As part of the original study there was a partner diary too," he said. In fact, it was corroborating evidence from the women that really convinced him Viagra works.
"We had men saying they hadn't had erections for years, who said they were able to have sex for the first time. I thought, well, this is too good to be true, and I didn't believe it until I saw the partners say 'Yeah, we hadn't had sex for 10 years and we did.'"
But he said partner input was left out of the New England Journal of Medicine study because it was not appropriate. "It would confuse the issue - people would say you are measuring female sexual response there," he said.
"Less than a third of the females actually reported information," added Goldstein, who led the original study. "It's not really strong data."
Plus there were different levels of agreement. In all-or-nothing cases, where a man had been completely impotent, he and his partner always agreed on whether Viagra worked. The study found that 48 percent of these men who took Viagra and 13 percent of those given a sugar pill or placebo got erections.
"The spouses say the same," Steers said.
Differences came in the area of less-severe erectile dysfunction. Men who were able to achieve partial erections had a 70 percent response rate. That means 70 percent of men who took Viagra saw some sort of improvement.
Their wives or partners agreed there was improvement but rated the level somewhat lower than the men did. "When a man is judging improvement, they ... rate it higher," Steers said.
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