Representative Names: Keflex
Active Ingredients: Cephalexin Monohydrate
Generic Available: Yes
Rx Status: Available by prescription only

What is/are Keflex (Back to top)
CEPHALEXIN is a cephalosporin antibiotic. It kills or stops the growth of some bacteria. This medicine is used to treat many kinds of infections. It will not work for colds, flu, or other viral infections. This medicine may be used for other purposes; ask your health care provider or pharmacist if you have questions.


What should I tell my health care providers before I take this medicine? (Back to top)
They need to know if you have any of these conditions:

  • kidney disease
  • stomach or intestine problems, especially colitis
  • an unusual or allergic reaction to cephalexin, other cephalosporins, penicillins, other antibiotics, medicines, foods, dyes or preservatives
  • pregnant or trying to get pregnant
  • breast-feeding

How should I use this medicine? (Back to top)
Take this medicine by mouth with a full glass of water. Follow the directions on the prescription label. This medicine can be taken with or without food. Take your medicine at regular intervals. Do not take your medicine more often than directed. Take all of your medicine as directed even if you think you are better. Do not skip doses or stop your medicine early.

Talk to your pediatrician regarding the use of this medicine in children. While this drug may be prescribed for selected conditions, precautions do apply.

Overdosage: If you think you have taken too much of this medicine contact a poison control center or emergency room at once.

Note: This medicine is only for you. Do not share this medicine with others.


What if I miss a dose? (Back to top)
If you miss a dose, take it as soon as you can. If it is almost time for your next dose, take only that dose. Do not take double or extra doses. There should be at least 4 to 6 hours between doses.


What may interact with this medicine? (Back to top)

  • probenecid
  • some other antibiotics

This list may not describe all possible interactions. Give your health care provider a list of all the medicines, herbs, non-prescription drugs, or dietary supplements you use. Also tell them if you smoke, drink alcohol, or use illegal drugs. Some items may interact with your medicine.


What side effects may I notice from receiving this medicine? (Back to top)
Side effects that you should report to your doctor or health care professional as soon as possible:

  • allergic reactions like skin rash, itching or hives, swelling of the face, lips, or tongue
  • breathing problems
  • pain or trouble passing urine
  • redness, blistering, peeling or loosening of the skin, including inside the mouth
  • severe or watery diarrhea
  • unusually weak or tired
  • yellowing of the eyes, skin

Side effects that usually do not require medical attention (report to your doctor or health care professional if they continue or are bothersome):
  • gas or heartburn
  • genital or anal irritation
  • headache
  • joint or muscle pain
  • nausea, vomiting

This list may not describe all possible side effects. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.


What should I watch for while using this medicine? (Back to top)
Tell your doctor or health care professional if your symptoms do not begin to improve in a few days.

Do not treat diarrhea with over the counter products. Contact your doctor if you have diarrhea that lasts more than 2 days or if it is severe and watery.

If you have diabetes, you may get a false-positive result for sugar in your urine. Check with your doctor or health care professional.


Where should I keep this medicine? (Back to top)
Keep out of the reach of children.

Store at room temperature between 59 and 86 degrees F (15 and 30 degrees C). Throw away any unused medicine after the expiration date.

NOTE: This sheet is a summary. It may not cover all possible information. If you have questions about this medicine, talk to your doctor, pharmacist, or health care provider.


Last Updated:June 02, 2007

©2008 Express Scripts, Inc. All Rights Reserved.
These materials are the property of Express Scripts, Inc. and are protected by copyright, trademark, and other laws. Permission for use is granted only for personal, noncommercial purposes.

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