New details on the side effects of the diabetes drug Avandia have been released, indicating it can cause 50% more weight gain than similar medications and double the risk of dangerous fluid retention in the body.
The review of 18 previous studies, involving 8000 patients, also echoes earlier warnings that the drug can elevate the risk of bone fractures and heart problems. But GlaxoSmithKline, the maker of Avandia, says the analysis included too few long-term studies to produce reliable results.
Avandia, known generically as rosiglitazone, received approval in the US in 1999 as a pill to help diabetics control their blood sugar levels. The drug works partly by inhibiting certain receptors on the surface of cells throughout the body, making them more willing to take up the sugar glucose.
Fluid retention
Now, a team of researchers led by Bernd Richter at Heinrich Heine University in Dusseldorf, Germany, has found more bad news to report about Avandia.
The team reviewed 18 studies, which had an average follow-up time of about six months. They found the risk of dangerous fluid retention in the body – a condition known as oedema – doubled in those taking the Avandia, compared with patients on other diabetes medications. The diabetics taking Avandia had a 7% risk of oedema – five times higher than those taking placebos.
Oedema is characterised by swelling of the ankles and legs, but can lead to more than just discomfort. Richter explains that the extra fluid in the body can create more work for the heart, causing a shortness of breath and possibly heart failure.
His team’s analysis also showed that patients receiving Avandia gained 50% more weight, on average, than their counterparts on other diabetes medications (2.1 kilograms compared with 1.4 kg).
These new findings, added to the earlier results suggesting the increased risk of heart attack and bone fractures with Avandia, should be a matter of concern, says Richter.
Richter adds that it is unclear exactly why the drug would cause complications such as oedema: “Nobody knows exactly why this happens”
