A large study has provided fresh evidence that a drug widely used to treat high blood pressure may not be the best option for many patients.
Beta blockers are commonly prescribed
A Swedish team analysed data on more than 105,000 people and found beta blockers were not as effective as other drugs in reducing high blood pressure.
The Lancet findings echo a high profile international study last month which found modern drugs were more effective.
Beta blockers are used to treat more than two million UK people alone.
Across the world, more than a quarter of the adult population - nearly one billion people - have high blood pressure.
The researchers, from Umea University Hospital, first challenged the effectiveness of beta blockers last year in a preliminary study.
They found that one of the drugs, atenolol, was less effective than other drugs at reducing the risk of heart and circulation problems in patients with high blood pressure.
The same team has now examined the results of 13 trials.
They found that the risk of stroke was 16% higher with beta blockers than with other drugs - and the overall chance of dying was 3% higher.
When the team looked at atenolol separately, the risk of stroke was 26% higher than for other drugs.
A separate analysis showed that beta blockers cut the risk of a stroke by just 19% compared to having no treatment at all - about half the effect expected from previous trials.
Lead researcher Professor Lars Hjalmar Lindholm said: "Switching hypertension treatment from beta blockers to other low-cost antihypertensive drugs in patients without heart disease should have a major health effect without increasing the cost.
"Such a change, however, should be carried out slowly and under a doctor's supervision.
"In comparison with other antihypertensive drugs, the effect of beta blockers is clearly suboptimum with a higher risk of stroke.
"We therefore believe that beta blockers should not remain as first choice in the treatment of primary hypertension."
In September the full results from the Ascot study found that beta blockers were out-performed by newer drugs such as calcium channel blockers and ACE inhibitors.
The NHS drug watchdog, the National Institute for Health and Clinical Excellence (NICE), has said it will consider its advice on blood pressure lowering drugs in light of recent data.
Alison Shaw, of the British Heart Foundation, said beta blockers had a wide range of benefits for patients besides lowering blood pressure.
"There is strong evidence that beta-blockers help to prevent angina attacks and reduce heart attack risk for people with coronary heart disease.
"People taking beta-blockers should not consider stopping or changing their medications on the basis of this study.
"However, they could discuss the other options for successful blood pressure lowering with their doctor.
"There is a wide range of possible medications which can be selected to help control blood pressure.
"To achieve this there is often a need for people with high blood pressure to take a combination of medications - one of these could be a beta-blocker."