NovoNorm (Novo Nordisk)
0.5 mg tablets
Approved indication: type 2 diabetes
Australian Medicines Handbook Section 10.1
Patients with non-insulin dependent diabetes have impaired insulin secretion and a resistance to the effects of insulin. If non-drug treatment fails, patients can be given a sulfonylurea, to stimulate insulin secretion, or metformin, to improve insulin sensitivity.1 When these drugs fail to control the blood glucose concentrations, repaglinide can be considered.
Repaglinide is not a sulfonylurea, but it stimulates the release of insulin from the pancreas. A dose is taken before meals. It is quickly and completely absorbed, but has a bioavailability of 63%. The peak plasma concentration is reached within an hour of the dose, and a response begins within 30 minutes. Repaglinide is almost completely metabolised by the liver and is cleared from the circulation within six hours.
In clinical trials, repaglinide was more effective than a placebo at reducing blood glucose concentrations. Its efficacy, in trials lasting up to 14 months, seemed to be similar to that of glibenclamide. In a trial lasting several months, the combination of metformin and repaglinide decreased HbA1c and fasting glucose more than either drug alone.
The most common adverse event in the clinical trials of repaglinide was hypoglycaemia. The incidence of hypoglycaemia was similar to that seen with other oral hypoglycaemic drugs. It is important that the dose is titrated for each patient. Patients begin with 0.5 mg and then increase the dose at 1-2 week intervals. The maximum daily dose is 16 mg. Other adverse events resemble those of the sulfonylureas.
Metformin is usually the first drug prescribed for obese patients with diabetes.1 Repaglinide may be a useful addition, if treatment with metformin alone is inadequate. While repaglinide's quick action is beneficial, it is not clear if it has any advantage over short-acting sulfonylureas. If overseas prices are reflected in Australia, any advantages are likely to be outweighed by the cost of repaglinide.