Sitagliptin (also known as Januvia), is a new once-daily tablet to lower blood glucose in people with type 2 diabetes. Sitagliptin is the first in a new class of type 2 diabetes therapies, dipeptidyl peptidase-4 (DPP-4) inhibitors. These drugs act in a different way from other tablets to lower blood glucose.

Sitagliptin became available in the UK in 2007. Its licenced indications have recently been expanded. It can now be added into to metformin, a sulphonylurea or a thiazolidinedione when these medications plus diet and exercise alone do not provide adequate blood glucose control. It can also be added to metformin and a sulphonylurea as so-called triple therapy.

Sitagliptin is effective in lowering blood glucose without causing weight gain. It is not known however how effective it will be in the long term in reducing the risk of developing complications of diabetes.

Sitagliptin reduces blood glucose concentrations by increasing the effects of ‘incretins’. Incretins are naturally ocurring hormones in the body which increase insulin release from the pancreas. Sitagliptin may also help to protect the beta cells which are the cells that produce insulin in the pancreas but this effect remains unproven.

Sitagliptin is given in tablet form in a dose of 100mg taken once daily.

There are very few side effects. Nausea has been reported. Sitagliptin might cause very low blood glucose values (hypoglycaemia) when given with other agents particularly sulphonylureas.