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Keflex vs. Amoxicillin

Are Keflex and Amoxicillin the Same Thing?

Keflex (cephalexin) and Amoxil amoxicillin are both antibiotics prescribed to treat bacterial infections.

Amoxicillin is also used before dental procedures in patients identified with certain heart-related conditions to prevent bacterial infections of the heart known as endocarditis.

These drugs belong to different drug classes. Keflex is a cephalosporin antibiotic and amoxicillin is a penicillin-type antibiotic.

Brand names for amoxicillin include Amoxil and Moxatag.

What Are Possible Side Effects of Keflex?

Common side effects of Keflex include:

What Are Possible Side Effects of Amoxicillin?

Common side effects of Amoxicillin include:

  • mild headache (not a migraine),
  • pain or chest tightness,
  • pressure or heavy feeling in any part of your body,
  • weakness,
  • feeling hot or cold,
  • dizziness,
  • spinning sensation,
  • drowsiness,
  • nausea,
  • vomiting,
  • drooling,
  • unusual taste in your mouth after using nasal spray,
  • burning/numbness/pain/irritation in your nose or throat after using nasal spray, or
  • flushing (warmth, redness, or tingling under the skin).

What is Keflex?

Keflex (cephalexin) is a cephalosporin antibiotic prescribed to treat bacterial infections. Keflex is also used before dental procedures in patients identified with certain heart-related conditions to prevent bacterial infections of the heart known as endocarditis. Keflex is available as a generic drug.

What is Amoxicillin?

Amoxil (amoxicillin) is a penicillin-type antibiotic used to treat infections caused by bacteria that are B-lactamase negative (B-lactamase positive bacteria are usually resistant to Amoxil); these infections usually occur in the skin, lungs, urinary tract and eye, ears, nose, and throat. Amoxil is available as a generic drug termed amoxicillin. Amoxil may be combined with other drugs (for example, clavulanic acid [Augmentin]), to make the antibiotic more effective.

 

What Drugs Interact With Keflex?

Keflex and amoxicillin may interact with probenecid and blood thinners.

Keflex may also interact with metformin.

What Drugs Interact With Amoxicillin?

Amoxil may interact with probenecid, blood thinners, other antibiotics, or sulfa drugs. Tell your doctor all medications and supplements you use. Treatment in pregnant women and women who are breastfeeding should be done with caution.

 

How Should Keflex Be Taken?

Keflex dosage depends on the condition being treated. Keflex should be used with caution in patients who have kidney disease and those who report a history of penicillin allergy.

How Should Amoxicillin Be Taken?

Amoxicillin is available in many preparations (capsules, tablets, chewable tablets, powder for oral suspension and pediatric oral suspension). Serious reactions of Amoxil include anaphylactic reactions that can be life-threatening; patients allergic to penicillins should not be given Amoxil. Amoxil may interact with probenecid, blood thinners, other antibiotics, or sulfa drugs. Tell your doctor all medications and supplements you use. Treatment in pregnant women and women who are breastfeeding should be done with caution.