• Basic Info
• Top Questions
• Clinical Info
• Interactions

Before using cephalexin, tell your doctor if you are using any of the following drugs:

• a blood thinner such as warfarin (Coumadin);

• meftormin (Fortamet, Glucophage, Riomet, Actoplus, Avandamet, Metaglip); or

• probenecid (Benemid).

This list is not complete and there may be other drugs that can interact with cephalexin. Tell your doctor about all the prescription and over-the-counter medications you use. This includes vitamins, minerals, herbal products, and drugs prescribed by other doctors. Do not start using a new medication without telling your doctor.

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Call your doctor at once if you have any of these serious side effects:

• diarrhea that is watery or bloody;

• seizure (convulsions);

• fever, sore throat, and headache with a severe blistering, peeling, and red skin rash;

• pale or yellowed skin, dark colored urine, fever, confusion or weakness;

• easy bruising or bleeding, unusual weakness;

• confusion, agitation, hallucinations (seeing things that are not there); or

• urinating less than usual or not at all.

Less serious side effects may include:

• mild nausea, vomiting, diarrhea;

• dizziness, tired feeling;

• joint pain; or

• vaginal itching or discharge.

This is not a complete list of side effects and others may occur. Tell your doctor about any unusual or bothersome side effect.