Interaction Checker

Cephalexin interactions

Cephalexin (Keflex), a cephalosporin has 55 documented interactions across the FDA labels and fact sheets we index: 8 major, 20 moderate, 27 minor, and 0 where a label reports no significant interaction. Each entry below quotes the sentence behind it. This drug page is a starting point, not a verdict for your situation.

Major interactions (8)

  • Amoxicillinpenicillin antibioticMajor

    AMOXIL is contraindicated in patients who have experienced a serious hypersensitivity reaction (e.g., anaphylaxis or Stevens-Johnson syndrome) to AMOXIL or to other β-lactam antibacterial drugs (e.g., penicillins and cephalosporins). (Amoxicillin label, Contraindications)

  • Amoxicillin and clavulanatepenicillin antibioticMajor

    History of a serious hypersensitivity reaction (e.g., anaphylaxis or Stevens-Johnson syndrome) to AUGMENTIN or to other beta‑lactams (e.g., penicillins or cephalosporins). (Amoxicillin and clavulanate label, Contraindications)

  • Ampicillinpenicillin antibioticMajor

    CONTRAINDICATIONS The use of Ampicillin is contraindicated in individuals with a history of serious hypersensitivity reactions (e.g., anaphylaxis or Stevens-Johnson syndrome) to ampicillin or to other beta-lactam antibacterial drugs. (Ampicillin label, Contraindications)

  • CefadroxilcephalosporinMajor

    Cephalexin is contraindicated in patients with known hypersensitivity to cephalexin or other members of the cephalosporin class of antibacterial drugs. (Cephalexin label, Contraindications)

  • CefdinircephalosporinMajor

    Cephalexin is contraindicated in patients with known hypersensitivity to cephalexin or other members of the cephalosporin class of antibacterial drugs. (Cephalexin label, Contraindications)

  • CefiximecephalosporinMajor

    Cephalexin is contraindicated in patients with known hypersensitivity to cephalexin or other members of the cephalosporin class of antibacterial drugs. (Cephalexin label, Contraindications)

  • CefpodoximecephalosporinMajor

    Cephalexin is contraindicated in patients with known hypersensitivity to cephalexin or other members of the cephalosporin class of antibacterial drugs. (Cephalexin label, Contraindications)

  • CefuroximecephalosporinMajor

    Cephalexin is contraindicated in patients with known hypersensitivity to cephalexin or other members of the cephalosporin class of antibacterial drugs. (Cephalexin label, Contraindications)

Moderate interactions (20)

  • ApixabananticoagulantModerate

    Those at risk include patients with renal or hepatic impairment, or poor nutritional state, as well as patients receiving a protracted course of antibacterial therapy, and patients receiving anticoagulant therapy. (Cephalexin label, Warnings and precautions)

  • DabigatrananticoagulantModerate

    Those at risk include patients with renal or hepatic impairment, or poor nutritional state, as well as patients receiving a protracted course of antibacterial therapy, and patients receiving anticoagulant therapy. (Cephalexin label, Warnings and precautions)

  • Dicloxacillinpenicillin antibioticModerate

    • Serious hypersensitivity (anaphylactic) reactions: Prior to use, inquire regarding history of hypersensitivity to beta-lactam antibacterial drugs. (Cephalexin label, Warnings and precautions)

  • EdoxabananticoagulantModerate

    Those at risk include patients with renal or hepatic impairment, or poor nutritional state, as well as patients receiving a protracted course of antibacterial therapy, and patients receiving anticoagulant therapy. (Cephalexin label, Warnings and precautions)

  • Empagliflozin and metforminSGLT2 inhibitorModerate

    • Metformin: increased metformin concentrations. (Cephalexin label, Drug interactions)

  • EnoxaparinanticoagulantModerate

    Those at risk include patients with renal or hepatic impairment, or poor nutritional state, as well as patients receiving a protracted course of antibacterial therapy, and patients receiving anticoagulant therapy. (Cephalexin label, Warnings and precautions)

  • Ethacrynic acidloop diureticModerate

    Ethacrynic acid may increase the ototoxic potential of other drugs such as aminoglycoside and some cephalosporin antibiotics. (Ethacrynic acid label, Drug interactions)

  • FondaparinuxanticoagulantModerate

    Those at risk include patients with renal or hepatic impairment, or poor nutritional state, as well as patients receiving a protracted course of antibacterial therapy, and patients receiving anticoagulant therapy. (Cephalexin label, Warnings and precautions)

  • Furosemideloop diureticModerate

    Cephalosporin Furosemide can increase the risk of cephalosporin-induced nephrotoxicity even in the setting of minor or transient renal impairment. (Furosemide label, Drug interactions)

  • GentamicinaminoglycosideModerate

    Increased nephrotoxicity has been reported following concomitant administration of aminoglycoside antibiotics and cephalosporins. (Gentamicin label, Drug interactions)

  • Glyburide and metforminsulfonylureaModerate

    • Metformin: increased metformin concentrations. (Cephalexin label, Drug interactions)

  • HeparinanticoagulantModerate

    Those at risk include patients with renal or hepatic impairment, or poor nutritional state, as well as patients receiving a protracted course of antibacterial therapy, and patients receiving anticoagulant therapy. (Cephalexin label, Warnings and precautions)

  • MetforminbiguanideModerate

    • Metformin: increased metformin concentrations. (Cephalexin label, Drug interactions)

  • MycophenolateimmunosuppressantModerate

    Examples Cyclosporine A, trimethoprim/sulfamethoxazole, bile acid sequestrants (cholestyramine), rifampin as well as aminoglycoside, cephalosporin, fluoroquinolone and penicillin classes of antimicrobials Drugs Modulating Glucuronidation Clinical Impact Concomitant use with drugs inducing glucuronidation decreases MPA systemic exposure, potentially reducing MYHIBBIN… (Mycophenolate label, Drug interactions)

  • Penicillin Gpenicillin antibioticModerate

    • Serious hypersensitivity (anaphylactic) reactions: Prior to use, inquire regarding history of hypersensitivity to beta-lactam antibacterial drugs. (Cephalexin label, Warnings and precautions)

  • Penicillin Vpenicillin antibioticModerate

    • Serious hypersensitivity (anaphylactic) reactions: Prior to use, inquire regarding history of hypersensitivity to beta-lactam antibacterial drugs. (Cephalexin label, Warnings and precautions)

  • Pioglitazone and metforminthiazolidinedioneModerate

    • Metformin: increased metformin concentrations. (Cephalexin label, Drug interactions)

  • RivaroxabananticoagulantModerate

    Those at risk include patients with renal or hepatic impairment, or poor nutritional state, as well as patients receiving a protracted course of antibacterial therapy, and patients receiving anticoagulant therapy. (Cephalexin label, Warnings and precautions)

  • Sitagliptin and metforminDPP-4 inhibitorModerate

    • Metformin: increased metformin concentrations. (Cephalexin label, Drug interactions)

  • WarfarinanticoagulantModerate

    Those at risk include patients with renal or hepatic impairment, or poor nutritional state, as well as patients receiving a protracted course of antibacterial therapy, and patients receiving anticoagulant therapy. (Cephalexin label, Warnings and precautions)

Minor mentions (27)

  • BrivaracetamanticonvulsantMinor

    Anticonvulsant therapy can be given if clinically indicated. (Cephalexin label, Warnings and precautions)

  • Cannabidiol (prescription)anticonvulsantMinor

    Anticonvulsant therapy can be given if clinically indicated. (Cephalexin label, Warnings and precautions)

  • CarbamazepineanticonvulsantMinor

    Anticonvulsant therapy can be given if clinically indicated. (Cephalexin label, Warnings and precautions)

  • CenobamateanticonvulsantMinor

    Anticonvulsant therapy can be given if clinically indicated. (Cephalexin label, Warnings and precautions)

  • ClobazambenzodiazepineMinor

    Anticonvulsant therapy can be given if clinically indicated. (Cephalexin label, Warnings and precautions)

  • ClonazepambenzodiazepineMinor

    Anticonvulsant therapy can be given if clinically indicated. (Cephalexin label, Warnings and precautions)

  • Divalproex (valproate)anticonvulsantMinor

    Anticonvulsant therapy can be given if clinically indicated. (Cephalexin label, Warnings and precautions)

  • EslicarbazepineanticonvulsantMinor

    Anticonvulsant therapy can be given if clinically indicated. (Cephalexin label, Warnings and precautions)

  • EthosuximideanticonvulsantMinor

    Anticonvulsant therapy can be given if clinically indicated. (Cephalexin label, Warnings and precautions)

  • FelbamateanticonvulsantMinor

    Anticonvulsant therapy can be given if clinically indicated. (Cephalexin label, Warnings and precautions)

  • GabapentinanticonvulsantMinor

    Anticonvulsant therapy can be given if clinically indicated. (Cephalexin label, Warnings and precautions)

  • LacosamideanticonvulsantMinor

    Anticonvulsant therapy can be given if clinically indicated. (Cephalexin label, Warnings and precautions)

  • LamotrigineanticonvulsantMinor

    Anticonvulsant therapy can be given if clinically indicated. (Cephalexin label, Warnings and precautions)

  • LevetiracetamanticonvulsantMinor

    Anticonvulsant therapy can be given if clinically indicated. (Cephalexin label, Warnings and precautions)

  • OxcarbazepineanticonvulsantMinor

    Anticonvulsant therapy can be given if clinically indicated. (Cephalexin label, Warnings and precautions)

  • PerampanelanticonvulsantMinor

    Anticonvulsant therapy can be given if clinically indicated. (Cephalexin label, Warnings and precautions)

  • PhenobarbitalbarbiturateMinor

    Anticonvulsant therapy can be given if clinically indicated. (Cephalexin label, Warnings and precautions)

  • Phentermine and topiramateCNS stimulantMinor

    Anticonvulsant therapy can be given if clinically indicated. (Cephalexin label, Warnings and precautions)

  • PhenytoinanticonvulsantMinor

    Anticonvulsant therapy can be given if clinically indicated. (Cephalexin label, Warnings and precautions)

  • PregabalinanticonvulsantMinor

    Anticonvulsant therapy can be given if clinically indicated. (Cephalexin label, Warnings and precautions)

  • PrimidoneanticonvulsantMinor

    Anticonvulsant therapy can be given if clinically indicated. (Cephalexin label, Warnings and precautions)

  • RufinamideanticonvulsantMinor

    Anticonvulsant therapy can be given if clinically indicated. (Cephalexin label, Warnings and precautions)

  • TiagabineanticonvulsantMinor

    Anticonvulsant therapy can be given if clinically indicated. (Cephalexin label, Warnings and precautions)

  • TopiramateanticonvulsantMinor

    Anticonvulsant therapy can be given if clinically indicated. (Cephalexin label, Warnings and precautions)

  • Valproic acidanticonvulsantMinor

    Anticonvulsant therapy can be given if clinically indicated. (Cephalexin label, Warnings and precautions)

  • VigabatrinanticonvulsantMinor

    Anticonvulsant therapy can be given if clinically indicated. (Cephalexin label, Warnings and precautions)

  • ZonisamideanticonvulsantMinor

    Anticonvulsant therapy can be given if clinically indicated. (Cephalexin label, Warnings and precautions)

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Not medical advice. Severity reflects the label's wording, not your circumstances. A "major" flag can be routine under supervision and a "minor" one can matter at high doses. Ask a pharmacist.