A Study to Investigate the Glucose Lowering Effects of Dextromethorphan Alone or in Combination With Sitagliptin in Subjects With Type 2 Diabetes Mellitus (T2DM) After an Oral Glucose Tolerance Test

Overview

The study has a randomized, double-blind, placebo-controlled, double dummy and eight-way cross-over design. Males with T2DM on a stable metformin monotherapy will be screened for participation in the study. Eligible subjects will be randomized to receive DXM 30 mg, DXM 60 mg, DXM 90 mg alone or in combination with sitagliptin 100 mg, sitagliptin 100 mg alone, or placebo (for DXM and sitagliptin) on in total eight treatment days. An OGTT will be started 1 hour after study drug administration and blood glucose will be measured over the next 4 hours. There will be a 3 to 14-day washout period between doses.

This study is performed to determine the optimal dose of DXM that, compared to placebo, decreases glucose excursions following an OGTT. Doses of 30 mg, 60 mg and 90 mg DXM were chosen. Since DXM 60 mg was effective in the previous study in increasing insulin secretion, this dose will be kept. A lower dose (30 mg) will be given to see whether effects on insulin secretion are present also at lower doses and then translate into a BG lowering action. A higher dose (90 mg) will be added to see whether this way an effect on glucose excursion reduction occurs following an OGTT, (like previously demonstrated with 270 mg DXM) that can be related to an increase of insulin secretion.

Conditions