Metronidazole dosing

To evaluate impact of therapeutic intervention to alter metronidazole dosing... 

Table 115-12 provides treatment recommendations for Trichomonas infections. The standard therapy for trichomoniasis is metronidazole 2 g orally as a single dose cure rates are comparable with the recommended alternative regimen of 500 mg twice daily for 7 days. When sexual partners are treated simultaneously, cure rates greater than 95% are reported. If sexual partners are not treated concurrently, cure rates are somewhat lower. In limited clinical testing, single metronidazole doses of less than 1.5 g are associated with high failure rates fss,67,es,70-77... 

Spence MR, Harwell TS, Davies MC, Smith JL. The minimum single oral metronidazole dose for treating trichomoniasis A randomized, blinded study. Obstet Gynecol 1997 89 699-703. 

Intravenous metronidazole 500 mg or 1 g was given to 10 healthy subjects before and after taking rifampicin 450 mg daily for 7 days. Rifampicin reduced the AUC of metronidazole by 33% and increased its clearance by 44%. Results were the same with both metronidazole doses. ... 

BSS 525 mg four times a day + metronidazole 250 mg four times a day + tetracycline 500 mg four times a day + H2RA (conventional ulcer-healing dose)c... 

Advise women requiring treatment for trichomoniasis during lactation to discontinue breast-feeding for 12 to 24 hours after receiving single-dose metronidazole therapy in order to minimize risk to the infant.14 During this time, advise women to pump and discard breast milk in order to avoid engorgement. 

O For treatment of giardiasis (or as empirical treatment), metronidazole 250 mg three times daily for 7 days or tinida-zole 2 g as a single dose is recommended. 

O All symptomatic adults and children over the age of 8 years should be treated with metronidazole 250 mg three times daily for 7 days, or tinidazole 2 gas a single dose, or nitazoxanide 500 mg twice daily for 3 days.3 The pediatric dose of metronidazole is 15 mg/kg per day three times daily far 7 days. Alternative drugs include furazolidone 100 mg four times daily or paromomycin 25 to 30 mg/kg per day in divided doses daily for 7 days. Paromomycin may be used in pregnancy instead of metronidazole. Pediatric patients can also be treated with suspensions of either furazolidone 8 mg/kg per day in four divided doses far 7 days, or nitazoxanide (Alina) 100 to 200 mg every 12 hours for 3 days. 

Patients with symptomatic giardiasis and positive stool samples or positive ELISA tests should be treated with metronidazole for 7 days. Patients who fail initial therapy with metronidazole should receive a second course of therapy. Pregnant patients can receive paromomycin 25 to 30 mg/kg per day in divided doses for 7 days. Giardiasis can be prevented by good hygiene and by using caution in food and drink consumption. 

Patients with severe intestinal disease or liver abscess should receive metronidazole 750 mg three times daily for 10 days, followed by the luminal agents indicated above. The pediatric dose of metronidazole is 50 mg/kg per day in divided doses, which should be followed by a luminal agent. An alternative regimen of metronidazole is 2.4 g/day for 2 days in combination with the luminal agent. Tinidazole (Tindamax, recently introduced on the United States market) administered in a dose of 2 g daily for 3 days (pediatric dose 60 mg/kg for 5 days) is an alternative to metronidazole. If there is no prompt response to metronidazole or aspiration of the abscess, an antibiotic regimen should be added. Patients who cannot tolerate oral doses of metronidazole should receive an equivalent dose intravenously. 

Metronidazole maybe administered orally as a single 2-g dose or 500 mg twice daily for 7 days.17 Pregnant women should be prescribed the single dose of metronidazole. Cure rates are greater than 90% when metronidazole is administered as either a single 2-g dose or a 7-day regimen. Possible adverse effects include an unpleasant metallic taste, reversible neutropenia, urticaria, rash, flushing, dry mouth, darkened urine, and a disulfiram-like reaction. 

Tinidazole, a second-generation nitroimidazole with protozoal and anaerobic activity, has been available outside the United States for over 30 years.18 Recently, the Food and Drug Administration (FDA) approved it for use in the United States. As a single 2-g dose, tinidazole has an efficacy equivalent to a 2-g dose of metronidazole. Tindazole also has a longer half-life than metronidazole, 14 and 7 hours respectively, and penetrates into male reproductive tissue better than metronidazole. 

Levofloxacin 500 mg PO daily for 14 days with or without metronidazole 500 mg PO twice daily for 14 days Ceftriaxone 250 mg IM single dose and probenecid 1 g single dose, plus doxycycline 100 mg PO twice daily for 14 days with or without metronidazole, 500 mg PO twice daily for 14 days Third-generation cephalosporin plus doxycycline 100 mg PO twice daily for 14 days with or without metronidazole 500 mg PO twice daily for 14 days... 

Anaerobes Clindamycin6 Adult 600-900 mg IV every 8 hours 300 150 mg oral every 6-8 hours Pediatric6 25 10 mg/kg per day IV in divided doses every 6-8 hours 1 0-30 mg/kg per day orally in divided doses every 6-8 hours Metronidazole 5-6 Adult 500 mg IV/oral every 8 hours Pediatric6 30 mg/kg per day IV/oral in divided doses every 6-8 hours ... 

The two most frequently used antibiotics are metronidazole and vancomycin. Metronidazole is recommended as first-line therapy because of the risk of development of vancomycin-resistant enterococci with vancomycin use, as well as its much higher cost. Metronidazole and vancomycin have similar efficacy, though in one study, symptoms resolved sooner with vancomycin [61]. Metronidazole is given orally for 10 days, at a dose of 1 g per day. Vancomycin is given orally for 10 days doses vary from 500 mg/day to 2 g/day. For mild to moderately severe CDAD, low-dose vancomycin is as effective as high-dose vancomycin. Vancomycin use is generally restricted to... 

Metronidazole at the dose of 20 mg/kg/day was also tested by Rutgeerts et al. [43] in the prevention of postoperative recurrence. Sixty patients were randomized to... 

GI complaints (e.g., anorexia, nausea, vomiting, diarrhea) are the most common adverse effects, with the single 2-g dose of metronidazole or... 

Symptomatic and Metronidazole 2 g po in a single dose Metronidazole 500 mg po 2 times daily... 

For treatment failures with metronidazole 2 g as a single dose. 

Ceturoxime axetil 20-30 mg/kg in two divided doses + metronidazole 30 mg/kg in three to four divided doses or clindamycin 10-30 mg/kg/day in three to four divided doses... 

Moderat severe infection Aminoglycoside + clindamycin 0.6-0.9 g IV every 8 hours or metronidazole Aminoglycosidee plus clindamycin 15 mg/kg/day IV in three divided doses or metronidazole 50-50... 

A single preoperative dose of cefazolin or cefoxitin is recommended for vaginal hysterectomy. For patients with /3-lactam hypersensitivity, a single preoperative dose of metronidazole or doxycycline is effective. 

S. Bielecka-Grzela and A. Klimowicz. Application of cutaneous microdialysis to evaluate metronidazole and its main metabolite concentrations in the skin after a single oral dose. J. Clin. Pharm. Ther. 28 465 169 (2003). 

Unlabeled uses The CDC has recommended the use of oral metronidazole for bacterial vaginosis (500 mg twice daily for 7 days). Single-dose therapy for bacterial vaginosis (2 g) also appears to be as effective as multiple-dose therapy. 

Excretion - The major route of elimination of metronidazole and its metabolites is via the urine (60% to 80% of the dose) fecal excretion accounts for 6% to 15% of the dose. Metronidazole has an average elimination half-life in healthy subjects of 8 hours. Metronidazole and its metabolites are removed by hemodialysis. 

Crohn s disease Crohn s disease patients are known to have an increased incidence of Gl and certain extraintestinal cancers. There have been some reports in the medical literature of breast and colon cancer in Crohn s disease patients who have been treated with metronidazole at high doses for extended periods of time. Candidiasis Candidiasis may present more prominent symptoms during therapy and requires treatment with a candicidal agent. 

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