Metformin's Effect on Drug Metabolism in Patients With Type 2 Diabetes

Summary

Type 2 diabetes is a major public health concern. It is widely established that type 2 diabetes in linked to activated innate immunity and increased levels of C-reactive protein and interleukin-6 (IL-6) in plasma. Studies in humans and in liver cells has shown that IL-6 downregulates important drug metabolizing enzymes in the liver (cytochrome P450 (CYP) enzymes). More than half of the most prescribed drugs are eliminated by biotransformation of these enzymes.

The investigators have previously shown that initiating glucose-lowering treatment (e.g. metformin, sulphonylureas and insulin) leads to decreased therapeutic efficacy of the blood-thinning vitamin-K antagonist warfarin. Due to the non-specific effect of glucose lowering drugs, the investigators hypothesize that this is caused by the glucose-lowering effect rather than drug-drug interactions caused by the individual drugs.

Based on the proposal that reversal of increased plasma glucose affects drug metabolism, the investigators will perform a clinical pharmacokinetic trial. The purpose of the study is to elucidate whether initiation of glucose-lowering treatment causes altered drug metabolism among patients with type 2 diabetes. The study will include newly diagnosed and untreated type 2 diabetes patients who will ingest a 6-drug cocktail consisting of probes for specific CYP enzymes. Plasma and urine will be drawn over 6 hours to determine concentrations of the drugs and their metabolites. Patients will then initiate metformin treatment and to assess both short- and long-term impact of glucose-lowering, the same 6-drug cocktail will be ingested, and concentrations measured, after three weeks and three months. To help understand the mechanism and the putative involvement of inflammation, markers of inflammation such as cytokines, transcription factors, etc. will also be assesses.

Conditions

• Diabetes Mellitus, Type 2

Interventions

DRUG

Metformin

500 mg tablet

DRUG

Caffeine

As part of a 6-drug cocktail caffeine 100 mg tablet will be administered as a single dose before the initiation of metformin treatment and 3 weeks and 12 weeks after. The drug will be used as a probe to assess CYP1A2 activity.

DRUG

Efavirenz

As part of a 6-drug cocktail efavirenz 50 mg coated tablet will be administered as a single dose before the initiation of metformin treatment and 3 weeks and 12 weeks after. The drug will be used as a probe to assess CYP2B6 activity.

DRUG

Losartan

As part of a 6-drug cocktail losartan 12.5 mg coated tablet will be administered as a single dose before the initiation of metformin treatment and 3 weeks and 12 weeks after. The drug will be used as a probe to assess CYP2C9 activity.

DRUG

Omeprazol

As part of a 6-drug cocktail Omeprazol 10 mg enteric-coated tablet will be administered as a single dose before the initiation of metformin treatment and 3 weeks and 12 weeks after. The drug will be used as a probe to assess CYP2C19 activity.

DRUG

Metoprolol

As part of a 6-drug cocktail metoprolol 12.5 mg release tablet will be administered as a single dose before the initiation of metformin treatment and 3 weeks and 12 weeks after. The drug will be used as a probe to assess CYP2D6 activity.

DRUG

Midazolam

As part of a 6-drug cocktail midazolam 2 mg oral solution will be administered as a single dose before the initiation of metformin treatment and 3 weeks and 12 weeks after. The drug will be used as a probe to assess CYP3A4 activity.

Sponsors & Collaborators

• University of Southern Denmark

  lead OTHER

Principal Investigators

• Ann-Cathrine Dunvald, MD · University of Southern Denmark

Study Design

Allocation

NA

Purpose

OTHER

Masking

NONE

Model

SINGLE_GROUP

Eligibility

Min Age

18 Years

Max Age

75 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2020-09-01

Primary Completion

2022-05-10

Completion

2022-05-10

Countries

• Denmark

Study Locations