The reappraisal of a common drug used to treat high blood pressure, taken by more than 50 million Americans each year, is causing consternation among doctors and patients, and alarm in the companies that manufacture the pills.

The medical value of beta-blockers, one of the five most often dispensed prescription drugs in America, was put in doubt earlier this month when a British study reported that claims that the drug reduces the chance of a heart attack or heart failure resulting from high blood pressure, or hypertension, were exaggerated.

British doctors were recommended to stop prescribing beta-blockers forthwith and patients on the drug were advised to ask for an alternative at their next quarterly medical check-up.

The study by the National Institute of Health and Clinical Excellence, based in London and Manchester, England, concluded that there were other drugs that “were better at treating the condition.” It also said that beta-blockers could have adverse side effects, like “increasing the risk of diabetes.”

Switching to more efficient drug alternatives is also seen as a means of saving money. The World Markets Research Center estimates that the National Health Service in Britain will save $461 million annually by retiring beta-blockers.

Retiring the drug in America would involve considerable discomfort for the makers of the drug here. Beta-blockers were the fifth most dispensed prescription drug in America in 2004, with 120.6 million dispensations, according to a study conducted by IMS Health, an intelligence source for the pharmaceutical industry. Total sales for beta-blockers in America amount to about $1.9 billion in 2004.

The suggestion that beta-blockers do not achieve the results claimed for them has not come as news to leading medical researchers in America. The Director of the Hypertension Program at St. Luke’s-Roosevelt Hospital in New York, Dr. Franz Messerli, said the British report supported his own research.

“While beta-blockers do lower blood pressure, there is no evidence that they reduce heart attacks and cardiovascular morbidity and mortality from hypertension,” he told The New York Sun. “Patients are only exposed to the costs, inconveniences, and side effects of betablockers without having any benefits.”

He added that his findings have “fallen on deaf ears for the past 10 years” and have encouraged American medical authorities to amend their guidelines on the value of beta-blockers, bringing it in line with best practice in Britain. “One can only hope that what is good for the goose is good for the gander,” he said, referring to the NICE’s decision to retire the drug and America’s reluctance to follow suit.

However, other American doctors have cast doubts over the legitimacy of the research conducted by Dr. Messerli. “The studies were not dosed properly, so the data is fallacious,” the chairman of the department of medicine at the New York Medical College, Dr. William Frishman, said.

He added that, despite the British decision to retire the drug, beta-blockers were “still important” in treating hypertension, and recommended that they should be used in a “combination regimen” with other treatments, like diuretics. “Combination treatment is necessary for many hypertensive patients,” he said.

The current American guidelines for hypertension treatment follow the recommendations of Dr. Frishman. The last report on hypertension treatment commissioned by the National Institute of Health in 2003 concluded that “diuretics should be used as initial therapy for most patients with hypertension in combination with one of the other drug classes.”

The report listed beta-blockers as one of the other drug classes, saying that there were “compelling indications” that they were effective in treating the “high risk conditions” of hypertension, like heart failure. The conclusion was based on “favorable outcome data from clinical trials.”

According to a spokesman from the heart, lung, and blood branch of the NIH, there are no intentions to reconsider these guidelines for the use of beta-blockers in hypertensive patients in America.”Guidelines are only reconsidered when there is an accumulation of new scientific evidence from within the country,” she said.

Beta-blockers are known to be effective in treating cardiovascular conditions that are not related to hypertension, such as angina. They are also used in recovery from heart attacks and heart failures. The drug will still be used to treat victims of non-hypertensive cardiovascular conditions in Britain.

However, Dr. Frishman also noted that many people who suffer from such problems also suffer from a high blood pressure that is not necessarily related to those problems. “Many people who need the drug would therefore not be allowed to get it, if beta-blockers are discarded for hypertension patients,” Dr. Frishman said.

The drug is also prescribed for non-cardiovascular related problems, such as migraines, glaucoma, and social phobia.

The pharmaceutical company AstraZeneca leads the market in beta-blocker sales. Their beta-blocker Toprol XL made up 63% of sales in 2004, worth approximately $1.2 billion.

However, officials at AstraZeneca’s American headquarters are confident that sales in America will not be affected. “This is not a decision affecting the American market, so we are not anticipating any impact,” the communications director for AstraZeneca US, Jim Minnick, said.”We would not want to speculate on any potential consequences if the drug were to be retired in America.”