Metformin side effects leading to poor adherence
A third of people do not take their prescribed metfomin due to side effects, according to a study.
Research from the University of Surrey also found that 23 per cent of sulfonylureas (such as gliclazide) and 20 per cent for pioglitazone prescriptions were not taken.
The study, published in the journal Diabetes, Obesity and Metabolism, combined data from clinical trials and observational studies looking at adherence rates for both tablet and injectable medicines, covering 1.6 million people with type 2 diabetes.
DPP4 inhibitors (gliptins), one of the newer medication classes have the highest rates of adherence, with only 10 to 20 percent of medication doses not taken. When comparing injectable medications, it was found that patients are twice as likely to stop taking GLP1 receptor agonists (such as exenatide) compared with insulin.
The researchers said that the the variance in adherence rates were in part due to side effects of the different drugs. Metformin commonly causes gastrointestinal symptoms such as diarrhoea and flatulence, whereas DPP4 inhibitors are generally better tolerated by the body. It is also thought that having to take the multiple doses a day required for some drugs may have an impact on people taking the required medication.
Clinical researcher at the University of Surrey Dr Andy McGovern said: “The importance of diabetes patients taking their prescribed medication cannot be underestimated. A failure to do so can lead to complications in their condition including eye disease and kidney damage. Medication which is not taken does no good for the patient but still costs the NHS money so this is an important issue.
“We have known for a long time that a lot of medication prescribed for chronic diseases never actually get taken. What this latest research suggests is that patients find some of these medication classes much easier to take than others.
“I urge anyone who is struggling to take their medication as prescribed, whether this is because of side effects or because the schedule is too complicated, to discuss this openly with their doctor or nurse. Fortunately for type 2 diabetes we have lots of treatment options and switching to a different medication class which is easier to take could provide an easy way to improve adherence. I would also encourage doctors and nurses to actively ask their patients about medication adherence.”
Data for the study was extracted from 48 studies, of these 25 compared oral therapies, 19 compared injectable therapies, three included comparison between oral and injectable therapies and one which compared an oral to an inhaled agent.
To access the study, click here.