NEW YORK -- The spectacular sales of the impotency treatment Viagra have tapered off in recent weeks.
In part, the sales rush has slowed because some insurers won't pay for the drug. In addition, patients who once raced to doctors' offices for prescriptions now find they use the pills only occasionally.
"Many people are having less sex than they had anticipated," said Dr. J. Francois Eid, director of the New York Presbyterian Impotency Center.
"The euphoria is probably gone," said Steve Lisi, an analyst with Mehta Partners, a New York investment firm.
In the week ended July 10, pharmacists filled 184,312 prescriptions for the little blue pill, compared to a peak of 303,424 in the week ended May 8, according to industry researcher IMS Health.
That still makes Viagra one of the nation's hottest selling drugs, on track to reach $1 billion in sales in its first year. But drug-industry analysts and doctors alike say the frenzy that followed Viagra's April 10 debut has calmed considerably.
Viagra's first few months on the market haven't been trouble-free. More than 30 people who used Viagra have died, prompting insurers Prudential HealthCare and Humana Inc. to refuse to pay for the drug.
Pfizer Inc., which makes Viagra, and the Food and Drug Administration point out that users of the drug are often elderly and have other health problems. Both have maintained that there's no evidence any of the patients would have died if they took the drug as directed.
Kaiser Permanente, the nation's largest health maintenance organization, decided that at about $10 a pill, Viagra is just too costly. And a few insurers have rationed the drug, offering to pick up the cost for one or two pills a week.
Independent analyst Hemant K. Shah believes the spotty reimbursement is responsible for Viagra's slumping sales. Indeed, erectile dysfunction remedies Muse and Caverject, which are more frequently covered by insurance policies, have recovered some of the market share they lost when Viagra debuted.
But others attributed the slowdown to the normal forces of supply and demand.
"This is something we observe with every product used to treat erectile dysfunction," said Dr. Eid. "There's always an initial, pent-up need for a new product, and everybody wants to try it."
Plenty of people who bought Viagra in its first few weeks on the market may be making their first prescription of eight to 10 pills last, observers said. Lisi and Eid agreed that Viagra users, who may have gone for years without sexual intercourse, often end up using the pill less frequently than they once imagined they would.
What's more, Eid said some patients give up on the drug. When used correctly, Viagra is extremely effective, allowing men to achieve an erection 60 to 70 percent of the time.
But in the initial rush to try the drug, many patients got scant advice from their physicians, and used the drug under less-than-ideal conditions, including taking Viagra too soon after a meal, with another drug, or without appropriate sexual stimulation.
"It can take half a dozen tries before everything goes perfectly," Eid said. "Some will give up after one or two attempts."
Pfizer reaped big profits from the drug in its recently ended second quarter. A spokeswoman Tuesday deemed the drop in sales insignificant, and wouldn't comment on the figures.
Myron Holubiak, general manager of the Plymouth Group, the consulting arm of IMS Health, agreed. He said the best indicator of Viagra's future potential is the refill rate, which has climbed steadily until a slight drop in the latest week's report.
"As long as people keep refilling their prescriptions, Viagra probably will reach $1 billion," he said. "In two months, we'll know a lot more."