AstraZeneca’s antihypertensive drug Atacand can delay the onset of high blood pressure in patients below the threshold for starting treatment, but only temporarily, according to the results of a new clinical trial.

The four-year TROPHY study of Atacand (candesartan cilexetil) is the first to test the hypothesis that intervening with blood pressure-lowering medications in patients with ‘pre-hypertension’ could delay or even prevent the onset of the disease.

For the first two years of the study, half of the 772 patients received a placebo and half received candesartan. For the next two years, all participants received a placebo, allowing the researchers to detect any lasting effects from drug treatment.

By study's end, the participants who received the blood pressure drug for two years and then stopped had a 15.6% lower risk of developing hypertension relative to those who received placebo for four years.

"However, the effect is moderate, and further studies in younger people and over longer periods of time are needed in order to demonstrate clinical usefulness,” said TROPHY’s principal investigator, University of Michigan Cardiovascular Center researcher Stevo Julius.

But the need for better strategies for pre-hypertensive people is urgent, said Julis. "What we have done so far is tell them to exercise and watch their diet, but these measures have not had any impact on public health. Rates of pre-hypertension are actually increasing,” he added, pointing out that rising blood pressure is an exponential, not linear process, which could potentially be interrupted with early intervention.

Julius called for more studies on pre-hypertension patients to complement the large amount of research on end-stage hypertension that has been carried out in recent years.

- Meanwhile, AstraZeneca may face a bill of $3.3 billion to free itself from its AMI joint venture with Merck & Co in the USA, if the latter exercises an option to terminate the relationship. The complex relationship involves Merck distributing some AZ products in the USA – notably antihypertensive Toprol XL (metoprolol), gastrointestinal treatment Nexium (esomeprazole) and Symbicort (budesonide and formoterol) for asthma - in return for royalties.