Nateglinide (Starlix) and Prandimet (metformin/repaglinide) are both used to manage blood sugar levels in people with Type 2 diabetes. They share a similarity in that they both contain a meglitinide, which helps the pancreas release more insulin. However, they have some important differences. Nateglinide contains only a meglitinide medication. Prandimet contained a combination of metformin and repaglinide, but it's no longer available in the U.S. Nateglinide is taken as a tablet three times a day before meals and is available as a generic. Common side effects of nateglinide include upper respiratory infections and dizziness. Nateglinide can cause low blood sugar, especially if meals are skipped, and should be used with caution if combined with other diabetes medications.