metronidazole, Flagyl

  • Pharmacy Author:
    Omudhome Ogbru, PharmD

    Dr. Ogbru received his Doctorate in Pharmacy from the University of the Pacific School of Pharmacy in 1995. He completed a Pharmacy Practice Residency at the University of Arizona/University Medical Center in 1996. He was a Professor of Pharmacy Practice and a Regional Clerkship Coordinator for the University of the Pacific School of Pharmacy from 1996-99.

  • Medical and Pharmacy Editor: William C. Shiel Jr., MD, FACP, FACR
    William C. Shiel Jr., MD, FACP, FACR

    William C. Shiel Jr., MD, FACP, FACR

    Dr. Shiel received a Bachelor of Science degree with honors from the University of Notre Dame. There he was involved in research in radiation biology and received the Huisking Scholarship. After graduating from St. Louis University School of Medicine, he completed his Internal Medicine residency and Rheumatology fellowship at the University of California, Irvine. He is board-certified in Internal Medicine and Rheumatology.

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GENERIC NAME: metronidazole

BRAND NAME: Flagyl

DRUG CLASS AND MECHANISM: Metronidazole is an antibiotic effective against anaerobic bacteria and certain parasites. Anaerobic bacteria are single-celled, living organisms that thrive in environments in which there is little oxygen (anaerobic environments). Anaerobic bacteria can cause disease in the abdomen (bacterial peritonitis), liver (liver abscess), and pelvis (abscess of the ovaries and the Fallopian tubes).

Giardia lamblia and ameba are intestinal parasites that can cause abdominal pain and diarrhea in infected individuals.

Trichomonas is a vaginal parasite that causes inflammation of the vagina (vaginitis). Metronidazole selectively blocks some of the functions within the bacterial cells and the parasites resulting in their death.

The FDA approved metronidazole tablets in July 1963.

PRESCRIBED FOR:

  • Metronidazole is used to treat parasitic infections including Giardia infections of the small intestine, amebic liver abscess, and amebic dysentery (infection of the colon causing bloody diarrhea), bacterial vaginosis, trichomonas vaginal infections, and carriers of trichomonas (both sexual partners) who do not have symptoms of infection.
  • Metronidazole is also used alone or in combination with other antibiotics in treating abscesses in the liver, pelvis, abdomen, and brain caused by susceptible anaerobic bacteria.
  • Metronidazole is also used in treating infection of the colon caused by a bacterium called C. difficile. Many commonly-used antibiotics can alter the type of bacteria that inhabit the colon. C. difficile is an anaerobic bacterium that can infect the colon when the normal types of bacteria in the colon are inhibited by common antibiotics. This leads to inflammation of the colon (pseudomembranous colitis) with severe diarrhea and abdominal pain.)
  • Metronidazole also is used in combination with other drugs to treat Helicobacter pylori (H. pylori) that causes stomach or intestinal ulcers.
  • Metronidazole topical gel is used for treating acne rosacea.
  • Metronidazole vaginal gel is used for treating bacterial vaginosis.

SIDE EFFECTS: Metronidazole is a useful antibiotic and is generally well tolerated with appropriate use.

Minor side effects include:

Serious side effects of metronidazole are rare and the drug should be stopped if these symptoms appear:

Medically Reviewed by a Doctor on 12/17/2014

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