11 August 2008

A new drug in a new class provides another option for improving blood glucose control in diabetes, but its effect on diabetes-related complications and mortality is not known. NPS RADAR reminds prescribers that when it comes to weighing up treatment options for people with diabetes, some drugs do have evidence for preventing diabetes-related complications as well as a more established safety profile.

The NPS RADAR review of sitagliptin (Januvia), the first of a new class of oral drugs for improving glycaemic control in type 2 diabetes, was published online at www.npsradar.org.au today.

Sitagliptin is PBS-listed for dual oral therapy with either metformin or a sulfonylurea, when a combination of these drugs is contraindicated or not tolerated.

National Prescribing Service Limited (NPS) Deputy CEO, Karen Kaye said that insulin or a glitazone are other treatment options when metformin cannot be used with a sulfonylurea.

“Sitagliptin is not associated with weight gain or an increased risk of hypoglycaemia, but we must consider a number of important points when choosing between treatment options for diabetes,” Ms Kaye said.

“Insulin has been shown to reduce the risk of diabetes-related complications. Sitagliptin’s efficacy and safety have not been compared with those of insulin, and its effect on diabetes-related complications and mortality is not known. NPS encourages prescribers not to delay treatment with insulin when oral drugs no longer control blood glucose.

“Weight gain and hypoglycaemia can still occur when sitagliptin is used with drugs that cause these effects (e.g. sulfonylureas). While there are safety concerns with the glitazones, the long-term benefit–harm profile of sitagliptin is yet to be established,” Ms Kaye said.

All drugs have benefits and harms. Adverse effects with sitagliptin include nasopharyngitis, upper respiratory tract infection, headache and nausea.

Postmarketing reports of anaphylaxis, angioedema, rash, urticaria and exfoliative skin conditions (including Stevens–Johnson syndrome) have occurred during treatment with sitagliptin. While a causal link is yet to be established, NPS RADAR advises prescribers to stop sitagliptin if a hypersensitivity reaction is suspected. Prescribers are advised to reduce the dose of sitagliptin in moderate to severe renal impairment.

NPS also published consumer reviews of both sitagliptin and duloxetine (Cymbalta), for major depressive disorder, in the latest editions of Medicine Update online at www.nps.org.au today.

NPS RADAR also reviews duloxetine, along with escitalopram (Lexapro, Esipram) for generalised anxiety disorder and social anxiety disorder (social phobia), memantine (Ebixa) for dementia in moderately severe Alzheimer’s disease and the role of automatic eGFR reporting in screening for kidney disease and drug -dosing decisions.

In addition, NPS RADAR carries an excerpt of the newly-released NPS position statement on zolpidem (Stilnox). Written to explain the background to the TGA’s safety change and to describe the current place of the drug in insomnia therapy, the statement can be read online at www.nps.org.au.

Health professionals who subscribe to NPS RADAR e-alerts are first to know of each edition as it is published. Visit www.npsradar.org.au to subscribe and to read all current and previous editions.

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.