The Effect of Losartan on Cephalexin

The goal of this clinical trial is to investigate the effects of the blood pressure-lowering drug losartan on the blood levels and urinary excretion of the antibiotic cephalexin during simultaneous and staggered ingestion in healthy volunteers. The main questions it aims to answer are: 1. Does losartan affect cephalexin levels and excretion when ingested at the same time? 2. Does a three-hour interval between ingestion of losartan and cephalexin eliminate a possible effect? Researchers will compare the effects of losartan ingested at the same time, losartan ingested three hours prior, and no losartan ingested on oral cephalexin in each participant to see whether an interaction exists and could be avoided. Participants will visit the research laboratory on three days during which they will ingest single doses of losartan at the same time with, three hours prior to, and not at all prior to ingesting single doses of cephalexin.

NCT Number	NCT07300670
Lead Sponsor	Aleksi Tornio Collaborators: Turku University Hospital, University of Turku, University of Helsinki, Helsinki University Central Hospital
Conditions	Possible Interaction Between Losartan and Cephalexin, Healthy
Enrollment	12 participants
Start Date	2026-03-04
Primary Completion	2026-05-08 (estimated)
Study Completion	2026-05-08 (estimated)
Updated on ClinicalTrials.gov	2026-03-25