What is Metronidazole hydrochloride - Meaning and definition

Published by Roberto Wenk. Last updated date: February 18, 2016.

The hydrochloride salt of a synthetic nitroimidazole derivative with antiprotozoal and antibacterial activities.
Although its mechanism of action is not fully elucidated, un-ionized metronidazole is readily taken up by obligate anaerobic organisms and is subsequently reduced by low-redox potential electron-transport proteins to an active, intermediate product. Reduced metronidazole causes DNA strand breaks, thereby inhibiting DNA synthesis and bacterial cell growth.

National Cancer Institute. NCI Drug Dictionary. Internet. September 15, 2009.

Published by Roberto Wenk. Reviewed by Alison Ramsey. Last updated date: January 11, 2019.

Adult
PO
Amoebiasis: 800 mg tid for 5 days (intestinal infection); 5-10 days (extra-intestinal infection). Max: 2.4 g/day.
Trichomoniasis: 2 g as a single dose, 200 mg tid for 7 days or 400 mg bid for 5-7 days.
Giardiasis: 2 g/day for 3 days, 400 mg tid for 5 days or 500 mg bid for 7-10 days.
Bacterial vaginosis: 2 g as a single dose or 400 mg bid for 5 -7 days.
Acute necrotizing ulcerative gingivitis: 200 mg tid for 3 days.
Acute dental infections: 200 mg tid for 3-7 days.
Anaerobic bacterial infections. Initial: 800 mg then 400 mg 8 hrly for 7 days. Max: 4 g/day.
Prophylaxis of post-op anaerobic bacterial infections: 400 mg 8 hrly 24 hr prior to surgery.
Eradication of H. pylori associated with peptic ulcer disease: 400 mg bid in combination with another antibacterial and a PPI or 400 mg tid, if given w/ omeprazole and amoxicillin.
Leg ulcers and pressure sores: 400 mg tid for 7 days.

IV
Anaerobic bacterial infections: 500 mg infused as 100 mL of a 5 mg/mL soln at 5 mL/min 8 hrly. Max: 4 g/day.
Prophylaxis of post-op anaerobic bacterial infections: 500 mg shortly before operation and repeated 8 hrly.

Rectal
Anaerobic infections: 1 g 8 hrly for 3 days, then 12 hrly thereafter until oral medication is possible.
Prophylaxis of post-op anaerobic bacterial infections: 1 g 2 hr before surgery then repeated 8 hrly for 3 days, then 12 hrly thereafter until oral medication is possible.

Topical/Cutaneous
Bacterial vaginosis - 0.75% gel: apply to affected area intravaginally once daily or bid for 5 days.
Fungating tumors - 0.75% gel: apply over the complete area and cover with non-adherent dressing once daily or bid.
Rosacea - 0.75% gel/cream/lotion: apply thinly to the affected area bid for 8 wk.

Adverse drug reactions: GI disturbances, furred tongue, glossitis, stomatitis, weakness, depression or confusion, urethral discomfort, darkening of the urine, raised liver enzyme values, cholestatic hepatitis, jaundice, pancreatitis.

Adapted from CIMS Drug Information System. Internet. Accessed on January 10, 2016.

Metronidazole hydrochloride

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