If an extra meal is eaten, an extra dose of repaglinide should be taken. The drug is most effective if taken on an empty stomach. Repaglinide offers the potential for good control of blood glucose levels after eating, whilst allowing for more flexibility in terms of mealtimes. In some people, the more flexible approach to eating may also help with weight loss. The most important of these are via its effects on insulin resistance.
Metformin increases insulin-stimulated transport of glucose from the blood into the body's cells.
It also reduces the amount of glucose that the liver releases into the bloodstream. These two actions of metformin both help to reduce blood glucose levels and reduce the stress on the beta cells for insulin. A useful additional effect of metformin is to reduce the absorption of glucose from the intestine. However, this contribution is probably of little significance in the overall picture. Metformin has also been associated with a reduction in heart and circulatory problems, which makes it the drug of choice for people with Type 2 diabetes, particularly in those who are overweight.