Cephalexin

16 interactions 229 cited references
Also sold as: Keflet® Tablets Keflex Keflex® Keftab® Tablets Panixine® Disperdose Rilexine
About Cephalexin

Cephalexin is a cephalosporin antibiotic used to treat bacterial infections of the respiratory tract, bones, skin, ears, and urinary tract. Read the full Cephalexin drug information page →

Dr. Brian Staiger, PharmD, BCPS
Medically reviewed by Dr. Brian Staiger, PharmD, BCPS · Updated Aug 10, 2026 · Editorial policy · Data sources

Sources: FDA prescribing information (Structured Product Labeling), the published literature cited in each entry, DDInter 2.0 (a major open-access drug-interaction database), and legacy DrugBank interaction data distributed by the NIH's RxNav service (decommissioned in 2024) — analyzed and reviewed by our pharmacist team. How we build this library →

Most serious with: Dofetilide Cholera Vaccine, Live Exenatide Furosemide Methotrexate Probenecid
1 Contraindicated 8 Major 7 Moderate
All (16) Contraindicated (1) Major (8) Moderate (7)

Contraindicated

Cephalexin Dofetilide Tikosyn Increased dofetilide exposure and an increased risk of cardiotoxicity (QT prolongation, torsades de pointes, cardiac arrest) Details

Major

Cephalexin Cholera Vaccine, Live Reduced immune response to the cholera vaccine Details Cephalexin Exenatide Bydureon Reduced oral antibiotics absorption and reduced efficacy of oral antibiotics Details Cephalexin Furosemide Disal Increased risk of cephalosporin-induced nephrotoxicity Details Cephalexin Methotrexate Jylamvo Increased methotrexate exposure, an increased risk of methotrexate-related severe adverse reactions, reduced active metabolite for... Details Cephalexin Probenecid Increased cephalexin exposure Details Cephalexin Exenatide Injection Bydureon Reduced oral antibiotics absorption and reduced efficacy of oral antibiotics Details Cephalexin Furosemide Injection Disal Increased risk of cephalosporin-induced nephrotoxicity Details Cephalexin Methotrexate Injection Abitrexate® Increased methotrexate exposure, an increased risk of methotrexate-related severe adverse reactions, reduced active metabolite for... Details

Moderate

Cephalexin Cholestyramine Prevalite Decreased cephalexin effectiveness Details Cephalexin Lixisenatide Delayed therapeutic effect Details Cephalexin Sucroferric Oxyhydroxide Altered absorption of cephalexin Details Cephalexin Typhoid Vaccine, Live Vivotif A decreased immunological response to the typhoid vaccine Details Cephalexin Warfarin Coumadin Increased INR and an increased risk of bleeding Details Cephalexin Cholestyramine Resin Locholest® Decreased cephalexin effectiveness Details Cephalexin Lixisenatide Injection Adlyxin® Delayed therapeutic effect Details

Check another drug

Still have questions about this combination?

Every question gets a real answer from a licensed pharmacist — free, and usually within a day.

Ask the pharmacist
Educational information only, not medical advice. Always confirm interactions with your pharmacist or prescriber before making any change to your medications.