Metronidazole

Anaerobic infection: load 15 mg/kg IV over 1 hour (about 1 g at 70 kg), then 7.5 mg/kg over 1 hour every 6 hours (about 500 mg at 70 kg); begin maintenance 6 hours after starting the load. Convert to oral when severity/response allow. Maximum 4 g/day. Typical course 7-10 days; bone/joint, lower-respiratory or endocardial infection may need longer.

Severe hepatic disease causes slower metabolism and accumulation: cautiously reduce doses and monitor concentrations/toxicity. Continuous nasogastric suction may remove sufficient drug to lower serum concentrations. The source says not to reduce specifically for anuria because dialysis removes accumulated metabolites.

Colorectal surgical prophylaxis: 15 mg/kg over 30-60 minutes, completed about 1 hour before surgery, then 7.5 mg/kg over 30-60 minutes at 6 and 12 hours after the initial dose. Complete the preoperative dose before incision; give additional 6-hourly doses if needed to maintain concentrations. Limit prophylaxis to the day of surgery.

Older adults may have altered pharmacokinetics; concentration monitoring may guide adjustment.

Historical trichomoniasis regimens in women: 2 g in one day, either once or as two 1 g doses, or 250 mg three times daily for 7 days. The source discusses potentially higher cure rates with 7-day treatment, supervised single-dose adherence, protection against reinfection while partners are treated, and differing tolerability. Treatment in men is individualized similarly.

The original text advises against first-trimester treatment and against a one-day course in pregnant patients when alternative treatment has been inadequate, because of higher fetal exposure. These historical pregnancy statements are preserved as source content, not current clinical advice. For repeat courses it proposes waiting 4-6 weeks, reconfirming infection by laboratory testing, and obtaining total/differential leukocyte counts before and after retreatment.

Adult intestinal amebiasis: 750 mg orally three times daily for 5-10 days. Amebic liver abscess: 500 or 750 mg three times daily for 5-10 days. Pediatric amebiasis: 35-50 mg/kg/day in three doses for 10 days.

Serious anaerobic infection usually begins with IV therapy; oral dosing is 7.5 mg/kg every 6 hours, maximum 4 g/day, usually 7-10 days. The same hepatic and anuria comments apply.

CrCl above 10 mL/min: no change. Below 10 without dialysis, the source explicitly lists different recommendations: no change at any impairment level (single-dose pharmacokinetics unchanged and dialysis removes metabolites), versus 50% of the usual dose at the same interval or 500 mg every 12 hours.

The GlobalRPh conclusion favors no routine reduction or interval extension based on the manufacturer discussion and pharmacokinetics. Both the alternative and the conclusion are retained rather than blended.

Extensive hemodialysis removal: schedule the conventional dose after dialysis on dialysis days. Continuous arteriovenous or venovenous hemofiltration: dose as for normal renal function in the source.