12 December 2007

National Prescribing Service Limited (NPS) urges all health professionals prescribing pioglitazone and rosiglitazone to ensure they are familiar with the latest version of the product information which contains new information about adverse effects.

Emerging data on cardiovascular risk, fractures and macular oedema are discussed in updated NPS RADAR reviews of pioglitazone (Actos), rosiglitazone (Avandia) and rosiglitazone with metformin (Avandament) published on www.npsradar.org.au this month. These drugs are used to treat type 2 diabetes mellitus.

Both pioglitazone and rosiglitazone improve glycaemic control. However, it is unclear if either drug improves diabetes–related clinical complications and mortality.

Both pioglitazone and rosiglitazone are associated with weight gain and fluid retention and should not be used in people with moderate to severe heart failure or those at risk of heart failure. Both drugs have been associated with an increased rate of fractures of the extremities (arm, hand and foot).

Prescribers should also be aware of a possible increased risk of myocardial ischaemia in patients taking rosiglitazone. The same risk has not been shown with pioglitazone but the possibility cannot be dismissed.

Rosiglitazone should not be initiated in patients already using insulin because of an increased risk of heart failure and myocardial ischaemia. While the same risk has not been shown when insulin is initiated in patients already on rosiglitazone, patients should nonetheless be closely monitored for oedema, rapid weight gain and other indicators of potential cardiovascular risk.

Prescribers should consider all of these factors when assessing the ratio of potential harms and benefits for each patient.

The December print edition also contains an NPS RADAR review of topiramate (Topamax) for migraine prevention, plus brief reviews of quetiapine (Seroquel) for acute mania and sevelamer (Renagel) 800 mg tablets for adults with chronic kidney disease on dialysis and were published at www.npsradar.org.au on 1 December.

ENDS

National Prescribing Service Limited (NPS) is an independent, non-profit organisation for Quality Use of Medicines funded by the Australian Government Department of Health and Ageing.