LONDON - Thousands of people who take prescription medicines for everyday conditions are gaining large amounts of weight as an unexpected side-effect, scientists have warned.
Researchers, who found that some patients were putting on up to 10kg in a year, say the drugs may even be contributing tothe nation's rocketing obesity epidemic.
All of the patients they studied, on medication for conditions as diverse as diabetes, epilepsy, depression, high blood pressure and schizophrenia, showed evidence of weight increase.
"Given the common and long-term use of many of these drugs," said the researchers, "it is likely that they play a significant contributory role in the increasing prevalence of obesity."
A team from Glasgow University and Glasgow Royal Infirmary reviewed and analysed data on drug use by more than 25,000 people.
All of the drugs included in the review are used to treat chronic diseases by large numbers of people. In the UK, it is estimated that 2.6 million people have been diagnosed with coronary heart disease, for which beta-blockers are widely prescribed. More than 400,000 people have epilepsy, and around 1.3 million people have type 1 or type 2 diabetes.
With many of the drugs, weight gain was significant and rapid, according to the researchers. Just how they lead to weight gain varies, and is in some cases unknown. Some, like corticosteroids, increase appetite, while beta-adrenoceptor blockers reduce metabolic rate.
Olanzapine and clozapine, for psychiatric conditions, resulted in the most weight gain - up to 10kg in 52 weeks. Insulin was found to increase weight by up to 6kg, while some drugs for depression added up to 3.5kg and some for high blood pressure, gains of up to 1.5kg. A heart drug added 2.5kg, while some for epilepsy added more than 5.5kg.
