What is Keflex?
Keflex is used to treat infections in adults and children who are at least 1 year old.
You should not use Keflex if you are allergic to cephalexin or to similar antibiotics, such as Ceftin, Cefzil, Omnicef, and others. Tell your doctor if you are allergic to any drugs, especially penicillins or other antibiotics.
Tell your doctor if you have kidney disease, liver disease, a stomach or intestinal disorder such as colitis, or diabetes.
Take this medication for the entire length of time prescribed by your doctor. Your symptoms may get better before the infection is completely treated. Keflex will not treat a viral infection such as the common cold or flu.
Before taking this medicine
To make sure Keflex is safe for you, tell your doctor if you have ever had
an allergy to any drug (especially penicillin);
liver or kidney disease; or
intestinal problems, such as colitis.
Tell your doctor if you are pregnant or breast-feeding.
How should I take Keflex?
Take Keflex exactly as prescribed by your doctor. Follow all directions on your prescription label and read all medication guides or instruction sheets.
Do not use Keflex to treat any condition that has not been checked by your doctor.
Use this medicine for the full prescribed length of time, even if your symptoms quickly improve. Skipping doses can increase your risk of infection that is resistant to medication. Cephalexin will not treat a viral infection such as the flu or a common cold.
Do not share Keflex with another person, even if they have the same symptoms you have.
This medicine can affect the results of certain medical tests. Tell any doctor who treats you that you are using this medicine.
Store the tablets and capsules at room temperature away from moisture, heat, and light.
What happens if I miss a dose?
Take the medicine as soon as you can, but skip the missed dose if it is almost time for your next dose. Do not take two doses at one time.
What happens if I overdose?
Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.
What to avoid
Antibiotic medicines can cause diarrhea, which may be a sign of a new infection. If you have diarrhea that is watery or bloody, call your doctor before using anti-diarrhea medicine.
Keflex side effects
Get emergency medical help if you have signs of an allergic reaction to Keflex (hives, difficult breathing, swelling in your face or throat) or a severe skin reaction (fever, sore throat, burning eyes, skin pain, red or purple skin rash with blistering and peeling).
Call your doctor at once if you have:
severe stomach pain, diarrhea that is watery or bloody (even if it occurs months after your last dose);
unusual tiredness, feeling light-headed or short of breath;
easy bruising, unusual bleeding, purple or red spots under your skin;
pale skin, cold hands and feet;
yellowed skin, dark colored urine;
fever, weakness; or
pain in your side or lower back, painful urination.
Common Keflex side effects may include:
indigestion, stomach pain; or
vaginal itching or discharge.
This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
What other drugs will affect Keflex?
Tell your doctor about all your other medicines, especially:
This list is not complete. Other drugs may interact with cephalexin, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible drug interactions are listed here.
There are several antibiotics that kill the common mouth bacteria that cause tooth infections. The best (first-line) antibiotics for tooth infection include: Amoxicillin, Penicillin, Cephalexin, Clindamycin, Azithromycin. Amoxicillin is often the first choice because it is widely effective and has the fewest gastrointestinal side effects. Continue reading
Penicillin or amoxicillin are considered the best first-line treatments for Strep throat. According to the CDC (Centers for Disease Control and Prevention) “ There has never been a report of a clinical isolate of group A strep that is resistant to penicillin”. For people with a penicillin allergy, treat Strep throat with either a narrow-spectrum cephalosporin (such as cephalexin or cefadroxil), clindamycin, azithromycin, or clarithromycin. Note that resistance to azithromycin and clarithromycin has been reported. Continue reading
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More about Keflex (cephalexin)
- Side Effects
- During Pregnancy or Breastfeeding
- Dosage Information
- Patient Tips
- Drug Images
- Drug Interactions
- Compare Alternatives
- En Español
- 81 Reviews
- Drug class: first generation cephalosporins
- Other brands
Related treatment guides
Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use Keflex only for the indication prescribed.
Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.
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