NCT03746106

The Effect of SLC19A3 Inhibition on the Pharmacokinetics of Thiamine

• Status: Completed
• Phase: Phase 4
• Study type: Interventional
• Enrollment: 7 (actual)
• Sponsor: University of California, San Francisco · Academic / Other
• Sex: All
• Age: 18 Years – 65 Years
• Healthy volunteers: Accepted

Summary

In Part 1, subjects will be administered thiamine, thiamine with metformin, and thiamine with trimethoprim. Part 2 will expand on Part 1 and subjects will be administered thiamine and thiamine with trimethoprim. The goal is to determine whether taking a drug and a vitamin together affects the body's ability to absorb, distribute, and eliminate thiamine (Vitamin B1).

Detailed description

Thiamine is an essential vitamin meaning humans must consume thiamine from their diet in order to stay healthy. Low thiamine levels can lead to adverse events. Thiamine is absorbed in the intestine by a transporter protein. This is made by the SLC19A3 gene. The SLC19A3 gene provides instructions for making the thiamine transporter protein, which moves thiamine into cells. Certain drugs, like metformin and trimethoprim, have been shown to interrupt function of the SLC19A3 gene. Metformin is a first-line therapy for patients with Type 2 diabetes and is associated with improvements in diabetic complications. Trimethoprim is an anti-bacterial drug that is often prescribed to treat infections such as urinary tract infections. At different phases of this study, participants will be administered thiamine, thiamine with metformin, and/or thiamine with trimethoprim to determine whether taking a drug and a vitamin together affects the body's ability to absorb, distribute, and eliminate thiamine. The levels of thiamine in the participants' blood and urine will be measured before and after taking thiamine or thiamine in combination with metformin and/or trimethoprim.

Conditions

• Vitamin B1 Deficiency
• Thiamine Deficiency

Interventions

Type	Name	Description
DRUG	Trimethoprim	300mg of trimethoprim will be given in combination with 5mg thiamine and compared to 5mg thiamine only for both Parts 1 and 2 of the study.
DRUG	Metformin	1000mg of metformin will be given in combination with 5mg thiamine and compared to 5mg thiamine only in Part 1 of the study.
DIETARY_SUPPLEMENT	Vitamin B1	5mg of thiamine will be given alone and in combination for both Parts 1 and 2 of the study.

Timeline

• Start date: 2019-01-28
• Primary completion: 2023-08-10
• Completion: 2023-08-10
• First posted: 2018-11-19
• Last updated: 2025-01-03
• Results posted: 2025-01-03

Locations

1 site across 1 country: United States

Regulatory

• FDA-regulated drug study