Side-effects Risk in Diabetes Drugs
November 24, 2008 by rainier
Lanched with fanfare four years ago and available on the Pharmaceutical Benefits Scheme since last December, Actos and Avandia – the so-called glitazones – could dramatically improve blood-sugar control in people whose condition was otherwise intractable, said the study leader, Peter Colman, director of Royal Melbourne Hospital’s Department of Diabetes and Endocrinology.But the once-daily pills carried “significant risk of side-effects”, said Associate Professor Colman, who analysed the benefits and risks to more than 200 hospital patients treated with them.
Side-effects might have been underestimated in trials that treated more well and more mobile people, Associate Professor Colman said. It was “not an uncommon occurrence” for a drug’s downsides to go undiscovered until it was in widespread use.
A dangerous build-up of fluid in the lungs occurred in 2.5 per cent of the Melbourne patients – much higher than in previous studies, he said. The condition occurred when the glitazones were given to patients with heart failure. While doctors were warned against prescribing them where heart failure was severe, “we found people with less severe cardiac problems did develop fluid overload”.
Hypoglycemia, where patients can become irrational or lose consciousness, occurred in 15 per cent of cases – again much higher than standard warnings suggest – though all the cases were associated with taking other medications as well as Avandia or Actos. Weight gain and water retention were also common.The Therapeutic Goods Administration says there have been 162 formal reports Australia-wide of people who have experienced possible side-effects from Actos or Avandia.It said six patients were reported to have died, but five were already very ill and it was unclear whether the drugs contributed to their deaths.
Associate Professor Colman said he wanted to emphasise to GPs that the drugs needed to be used with caution. “Careful patient selection and follow-up and realistic treatment goals are necessary,” he writes in this week’s issue of the Medical Journal of Australia.
Health Insurance Commission figures show subsidised prescriptions of glitazones have been rising steadily over the past year, reaching 20,000 in September. Patients must be unable to take more established therapies to qualify.
The director of the Diabetes Centre at Bankstown-Lidcombe Hospital, Jeff Flack, praised the study, saying it was “important to have real-life experience”. But some of the patients’ treatment had not been in accordance with current guidelines, which might have skewed the results, said Dr Flack, who is also president of the Australian Diabetes Society.
But the director of the International Diabetes Institute in Melbourne, Paul Zimmet, said the patients attending the public hospital clinic in the study were likely to be poorer and have more medical complications than normal.
