METRONIDAZOLE (FLAGYL)

 

Introduction:  Metronidazole also sometimes referred to as fragyl, is one of the most commonly prescribed and used drugs because of availability, being cheap and broad spectrum of activity.  This drug can act against both bacteria, and protozoa.

Therapeutic Class: Anti-infective, antiprotozoan, and Antibacterial

Pharmacologic Class: Drug that disrupts nucleic acid synthesis and sometimes act as a proton sink, by depriving the microbe of oxidative potential.

Actions and uses: Metronidazole is the prototype drug for most forms of amebiasis, being effective against both the intestinal and hepatic stages of the disease. Resistant forms of E. histolytica have not yet emerged as a clinical problem with metronidazole therapy. Metronidazole is also a preferred drug for giardiasis and trichomoniasis. 

Metronidazole is unique among antiprotozoan drugs in that it also has antibiotic activity against anaerobic bacteria and thus is used to treat a number of respiratory, bone, skin, and CNS infections. 

Topical forms of metronidazole (MetroGel, MetroCream, MetroLotion) are used to treat rosacea, a disease characterized by skin reddening and hyperplasia of the sebaceous glands, particularly around the nose and face.

ADMINISTRATION ALERTS: The extended-release form must be swallowed whole and taken on an empty stomach. Metronidazole is contraindicated during the first trimester of pregnancy. Pregnancy category B

ADVERSE EFFECTS: Although adverse effects occur relatively frequently, most are not serious enough to cause discontinuation of therapy. The most common adverse effects of metronidazole are anorexia, nausea, diarrhea, dizziness, and headache. Dryness of the mouth and an unpleasant metallic taste may be experienced. Although rare, metronidazole can cause bone marrow suppression. 

Contraindications: Metronidazole is contraindicated in patients with trichomoniasis during the first trimester of pregnancy and those with hypersensitivity to the drug. Metronidazole can cause bone marrow suppression; thus, it is contraindicated for patients with blood dyscrasias.

INTERACTIONS: Drug–Drug: Metronidazole interacts with oral anticoagulants to potentiate hypoprothrombinemia. In combination with alcohol, or other medications that may contain alcohol, metronidazole may elicit a disulfiram reaction. In patients who are taking lithium, the drug may elevate lithium levels.

RELATED;

1.  FLOROQUINOLONES  

2.  PENICILLINS  

3.  CEPHALOSPORINS

4.  DRUG USE IN RELATION TO PREGNANCY

5.  PHARMACOLOGY AND THERAPEUTICS

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