London: The range of drugs known as beta blockers which doctors may use to to treat high blood pressure increase the risk of diabetes, according to new research.
Diabetes increases the risk high risk of heart attacks, strokes and kidney disease. Patients on beta blockers are face a 50 per cent higher risk than with the latest drugs.
The National Institute for Clinical Excellence, the UK government body that approves drugs for public use said that doctors should use the newer ace inhibitors and calcium channel blockers should be the first choice treatment for the millions of Britons being treated for high blood pressure.
The results of a new clinical trial show beta blockers may hasten and, in some cases, induce diabetes.
Although many patients are being switched to newer drugs by their doctors when they go for a scheduled check-up, beta-blockers remain in wide use.
They are still considered the best treatment for conditions such as angina, and
doctors have warned patients not to stop taking them without medical advice as
sudden withdrawal may trigger a heart attack.
The trial which was reported at the World Congress of Cardiology in Barcelona which exposed the diabetes risk was led by Professor Neil Poulter,
co-director of the International Centre for Circulatory Health at Imperial
College London.
He said that the chance of a patient with raised blood pressure developing diabetes can be cut by newer treatments, irrespective of the patient’s initial level of risk. Many cases of diabetes could be prevented if doctors avoid prescribing the older treatments to hypertensive patients unless they specifically require them.
Despite the warning experts point out that for the remaining beta-blocker patients, the benefits of the drugs in lowering blood pressure still massively outweigh the diabetes risk, so they should not suddenly stop taking them.
The study looked at 14,000 patients in the UK, Ireland and Scandinavia, half of
whom were taking the old combination of the betablocker Atenolol and a diuretic.
The others were prescribed a calcium channel blocker called amlodipine and the
ace-inhibitor perindopril, and in this group 34 per cent fewer patients
developed diabetes over three years.
The study suggests the aceinhibitor protects against the condition, while the
other drug is neutral. But the beta-blocker and diuretic combination actually
encourages diabetes.
THE BETTER ALTERNATIVE TO BETAS
BETA-BLOCKERS were introduced in the 1960s and were a mainstay of treatment
until the 1990s, when side effects such as reduced energy levels meant many
patients were switched to newer drugs.
Clinical trials over the last three years have suggested they are less effective
than newer versions. But they remain useful against angina and some other
conditions. Patients with these who also have high blood pressure may still get
them.
They work by blocking the action of a chemical called noradrenaline, which helps
prepare the body for emergencies.
Noradrenaline speeds up the heart, making it pump more forcibly and pushing up
blood pressure as a result. The drugs block the binding of the chemical on
receptors on the heart, slowing down its action.
New ace-inhibitor drugs work by blocking a process which narrows blood vessels
and so increases pressure. Calcium channel blockers also avoid narrowing of the
arteries by stopping muscle cells contracting.