Macrodantin vs. Keflex

Are Macrodantin and Keflex the Same Thing?

Macrodantin (nitrofurantoin) and Keflex (cephalexin) are antibiotics prescribed to treat or prevent urinary tract infections.

Keflex is also prescribed to treat bacterial infections such as upper respiratory infections, ear infections, and skin 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.

Macrodantin and Keflex are different types of antibiotics. Macrodantin is a nitrofuran antibiotic and Keflex is a cephalosporin antibiotic.

Side effects of Macrodantin and Keflex that are similar include headache, itching, rash, nausea, vomiting, upset stomach, diarrhea, and vaginal itching or discharge.

Side effects of Macrodantin that are different from Keflex include loss of appetite and rust-colored or brownish urine.

Side effects of Keflex that are different from Macrodantin include dizziness, tiredness, abdominal pain, joint pain, and swelling.

Both Macrodantin and Keflex may interact with probenecid.

Macrodantin may also interact with antacids, magnesium salicylate, and choline magnesium salicylate.

Keflex may also interact with blood thinners and metformin.

What Are Possible Side Effects of Macrodantin?

Side effects of Macrodantin include:

  • headache,
  • itching,
  • rash,
  • nausea,
  • upset stomach,
  • vomiting,
  • loss of appetite,
  • diarrhea,
  • rust-colored or brownish urine, or
  • vaginal itching or discharge.

What Are Possible Side Effects of Keflex?

Common side effects of Keflex include:

  • diarrhea,
  • dizziness,
  • tiredness,
  • headache,
  • stomach upset,
  • abdominal pain,
  • joint pain,
  • vaginal itching or discharge,
  • nausea,
  • vomiting,
  • itching,
  • swelling, and
  • rash.

What Is Macrodantin?

Macrodantin (nitrofurantoin) is an antibiotic prescribed to treat or prevent urinary tract infections. Macrodantin is available in generic form.

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.


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What Drugs Interact With Macrodantin?

Macrobid may also interact with magnesium salicylate or choline magnesium salicylate.

What Drugs Interact With Keflex?

Keflex and amoxicillin may interact with probenecid and blood thinners.

Keflex may also interact with metformin.

How Should Macrodantin Be Taken?

Macrodantin should be given with food to improve drug absorption and, in some patients, tolerance. Adults should take 50-100 mg four times a day-the lower dosage level is recommended for uncomplicated urinary tract infections.

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.


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DailyMed. Macrodantin Product Information.
FDA. Keflex Product Information.

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