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Cephalexin - Oral

Pronunciation: sef-a-LEX-in

Common Brand Name(s): Keflex

Important: How To Use This Information

This is a summary and does NOT have all possible information about this product. This information does not assure that this product is safe, effective, or appropriate for you. This information is not individual medical advice and does not substitute for the advice of your health care professional. Always ask your health care professional for complete information about this product and your specific health needs.

Uses

This medication is used to treat a wide variety of bacterial infections. This medication is known as a cephalosporin antibiotic. It works by stopping the growth of bacteria.

This medication will not work for viral infections (such as common cold, flu). Unnecessary use or misuse of any antibiotic can lead to its decreased effectiveness.

Other Uses

This section contains uses of this drug that are not listed in the approved professional labeling for the drug but that may be prescribed by your health care professional. Use this drug for a condition that is listed in this section only if it has been so prescribed by your health care professional.

This drug may also be used before dental procedures in people with certain heart conditions (such as artificial heart valves) to reduce the risk of a serious infection of the heart (bacterial endocarditis).

How To Use

Take this medication by mouth as directed by your doctor, usually every 6 to 12 hours with or without food.

If you are using the suspension, shake the bottle well before each dose. Measure the dose carefully using a special measuring device/spoon. Do not use a household spoon because you may not get the correct dose.

The dosage is based on your medical condition and response to treatment. In children, the dose is also based on weight.

For the best effect, take this antibiotic at evenly spaced times. To help you remember, take this medication at the same time(s) every day.

Continue to take this medication until the full prescribed amount is finished, even if symptoms disappear after a few days. Stopping the medication too early may result in a return of the infection.

Tell your doctor if your condition lasts or gets worse.

Side Effects

Diarrhea, nausea, vomiting, or upset stomach may occur. If any of these effects last or get worse, tell your doctor or pharmacist promptly.

Remember that this medication has been prescribed because your doctor has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

Use of this medication for prolonged or repeated periods may result in oral thrush or a new yeast infection. Contact your doctor if you notice white patches in your mouth, a change in vaginal discharge, or other new symptoms.

This medication may rarely cause a severe intestinal condition due to a bacteria called C. difficile. This condition may occur during treatment or weeks to months after treatment has stopped. Tell your doctor right away if you develop:

  • diarrhea that doesn't stop
  • abdominal or stomach pain/cramping
  • blood/mucus in your stool

If you have these symptoms, do not use anti-diarrhea or opioid products because they may make symptoms worse.

A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including:

  • rash
  • itching/swelling (especially of the face/tongue/throat)
  • severe dizziness
  • trouble breathing

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

In the US -

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.

In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

Precautions

Before taking cephalexin, tell your doctor or pharmacist if you are allergic to it; or to penicillins or other cephalosporins (such as cefpodoxime); or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

Before using this medication, tell your doctor or pharmacist your medical history, especially of:

  • kidney disease
  • stomach/intestinal disease (such as colitis)

The liquid form of this product may contain sugar. Caution is advised if you have diabetes. Ask your doctor or pharmacist about using this product safely.

Cephalexin may cause live bacterial vaccines (such as typhoid vaccine) to not work well. Tell your health care professional that you are using cephalexin before having any immunizations/vaccinations.

Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).

During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor.

This medication passes into breast milk. Consult your doctor before breast-feeding.

Drug Interactions

Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.

A product that may interact with this drug is:

  • dofetilide

This medication may interfere with certain lab tests (including Coombs' test, certain urine glucose tests), possibly causing false test results. Make sure lab personnel and all your doctors know you use this drug.

Overdose

If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call their local poison control center at 1-800-222-1222. Alberta residents can call PADIS (Poison and Drug Information Service) 24 hours a day at 1-800-332-1414. Canada residents can call a provincial poison control center. Symptoms of overdose may include: vomiting that is severe or doesn't stop, blood in the urine, seizures.

Notes

Do not share this medication with others.

This medication has been prescribed for your current condition only. Do not use it later for another infection unless your doctor tells you to.

Lab and/or medical tests (such as kidney function, cultures) may be done while you are taking this medication. Keep all medical and lab appointments. Consult your doctor for more details.

Missed Dose

If you miss a dose, take it as soon as you remember. If it is near the time of the next dose, skip the missed dose. Take your next dose at the regular time. Do not double the dose to catch up.

If you have questions about missing a dose or you don't have more medication, contact your healthcare provider or pharmacist.

Storage

Store the capsules and tablets at room temperature away from light and moisture. Do not store in the bathroom.

Store the suspension in the refrigerator. Do not freeze. Keep the container tightly closed. Discard any unused portion after 14 days.

Different brands of this medication may have different storage requirements. Read the package labeling or ask your pharmacist for the storage requirements for the product you are using. Keep all medications away from children and pets.

Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company.

This information does not replace the advice of a doctor. Healthwise, Incorporated, disclaims any warranty or liability for your use of this information. Your use of this information means that you agree to the Terms of Use. Learn how we develop our content.