RecruitingPhase 1

The Effect of Losartan on Cephalexin

Finland12 participantsStarted 2026-03-04

Plain-language summary

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.

Who can participate

Age range

18 Years – 40 Years

Sex

ALL

See this in plain English?

AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.

Inclusion Criteria: * written informed consent * 18-40 years of age * good health * systolic blood pressure of at least 115 mmHg * all screening laboratory results (P-Krea, Pt-GFReEPI, P-Na, P-K, P-ALAT, P-AFOS, P-GT, B-PVK+T) acceptable; minor deviations from reference ranges are acceptable at the discretion of a physician-scientist with the exceptions of Pt-GFReEPI which must be at or above the reference limit and P-K which must be at or below the higher reference limit (Reference limits: Tyks Laboratories, Turku University Hospital) * regarding female subjects, a negative pregnancy test (S-HCG-O) before the study, and the use of a highly effective contraceptive method (e.g. copper intrauterine device, bilateral tubal occlusion, vasectomised partner, or abstinence from heterosexual intercourse), according to CTFG Recommendations related to contraception and pregnancy testing in clinical trials, are required Exclusion Criteria: * inability to provide written informed consent in Finnish * remarkable illness * confirmed or reasonably suspected allergy to cephalexin, amoxicillin, benzylpenicillin, phenoxymethylpenicillin, piperacillin, cefaclor, or cefamandole * confirmed or reasonably suspected severe delayed allergic reaction to any beta-lactam antibiotic * underweight (BMI less than 18.5 kg/m2) * obesity (BMI greater than 30 kg/m2) * smoking * regular medication, including hormonal contraception in the form of pills, intrauterine device, subdermal implant etc. * current o…

Questions worth asking your doctor

Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.

1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?

Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.

Questions for the trial coordinator

The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.

1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?

A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.

What they're measuring

Plasma concentrations of cephalexin over time, the cumulative urinary excretion of cephalexin, and the pharmacokinetic parameters derived from these measurements following simultaneous or staggered ingestion of losartan

Timeframe: up to 8 hours after ingestion of cephalexin on three consecutive days separated by at least one-week intervals

Trial details

NCT IDNCT07300670

SponsorAleksi Tornio

Sponsor typeOTHER_GOV

Study typeINTERVENTIONAL

Primary completion2026-05-08

Contact for this trial

Aleksi Tornio, M.D., Ph.D.

+358504765715 aleksi.tornio@utu.fi

View on ClinicalTrials.gov More Possible Interaction Between Losartan and Cephalexin trials