Losartan's effect on cephalexin levels
The Effect of Losartan on Cephalexin
PHASE1 · Turku University Hospital · NCT07300670
This study will test whether taking the blood-pressure medicine losartan changes blood levels and urinary excretion of the antibiotic cephalexin in healthy adults when taken together or three hours apart.
Quick facts
| Phase | PHASE1 |
|---|---|
| Study type | Interventional |
| Enrollment | 12 (estimated) |
| Ages | 18 Years to 40 Years |
| Sex | All |
| Sponsor | Turku University Hospital (other gov) |
| Locations | 1 site (Turku, Southwest Finland) |
| Trial ID | NCT07300670 on ClinicalTrials.gov |
What this trial studies
Healthy adult volunteers will receive single doses of cephalexin on three separate visits under three conditions: cephalexin alone, cephalexin taken at the same time as losartan, and cephalexin taken three hours after losartan. Blood and urine samples will be collected to measure cephalexin concentrations and excretion over time. Each participant serves as their own control to compare pharmacokinetic differences between the conditions. The goal is to determine whether simultaneous dosing alters cephalexin exposure and whether a three-hour separation removes any effect.
Who should consider this trial
Good fit: Healthy adults aged 18–40 who can give informed consent in Finnish, have acceptable screening labs and systolic blood pressure ≥115 mmHg, and (for women) agree to highly effective contraception are ideal candidates.
Not a fit: People on chronic losartan therapy, those outside the 18–40 healthy range, pregnant individuals, or people with significant kidney, electrolyte, or blood-pressure abnormalities are unlikely to gain direct benefit from participation.
Why it matters
Potential benefit: If successful, the results could show whether simple timing of doses prevents an interaction and help guide safer co-use of losartan and cephalexin.
How similar studies have performed: Similar single-dose pharmacokinetic crossover studies have reliably identified drug–drug interactions, but a specific losartan–cephalexin interaction has not been widely reported.
Eligibility criteria
Show full inclusion / exclusion criteria
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 or planned pregnancy, and breastfeeding * less than three months elapsed since a prior clinical trial * less than three months elapsed since donating blood
Where this trial is running
Turku, Southwest Finland
- Unit of Clinical Pharmacology, Turku University Hospital — Turku, Southwest Finland, Finland (RECRUITING)
Study contacts
- Principal investigator: Aleksi Tornio, M.D., Ph.D. — Unit of Clinical Pharmacology, Turku University Hospital
- Study coordinator: Aleksi Tornio, M.D., Ph.D.
- Email: aleksi.tornio@utu.fi
- Phone: +358504765715
How to participate
- Review the eligibility criteria above with your treating physician.
- Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
- Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions: Possible Interaction Between Losartan and Cephalexin, Healthy, losartan, cephalexin, pharmacokinetic interaction, absorption