Tinidazole

Indications

Tinidazole is used for: Giardiasis, H. pylori infection, Surgical Prophylaxis, Bacterial vaginosis, Intestinal amoebiasis, Trichomoniasis, Acute necrotising ulcerative gingivitis, Hepatic amoebiasis

Adult Dose

Oral Bacterial vaginosis Adult: 2 g as single dose. May also be given as 2 g for 2 consecutive days or 1 g daily for 5 days. Anaerobic bacterial infections Adult: 2 g on the 1st day, followed by 1 g daily or 500 mg bid for 5-6 days. Prophylaxis of postoperative anaerobic bacterial infections Adult: 2 g as single dose 12 hr before surgery. Eradication of H. pylori associated with peptic ulcer disease Adult: 500 mg bid, given w/ clarithromycin and omeprazole for 7 days. Intestinal amoebiasis Adult: 2 g daily for 2 or 3 days. Hepatic amoebiasis Adult: 1.5-2 g daily for 3-6 days. Giardiasis Adult: 2 g as single dose. Trichomoniasis; Acute necrotising ulcerative gingivitis Adult: 2 g as single dose. In trichomoniasis, sexual partners should be treated at the same time. Intravenous IV Susceptible infections Initial: Infuse 800 mg, followed by 800 mg/day or 400 mg twice daily till PO can be given. Surgical prophylaxis 1.6 g as single infusion pre-op.

Child Dose

Oral Intestinal amoebiasis Child: >3 yr 50-60 mg/kg daily for 3 consecutive days. Max: 2 g/day. Hepatic amoebiasis Child: >3 yr 50-60 mg/kg daily for 5 days. Max: 2 g/day. Giardiasis Child: >3 yr 50-75 mg/kg as single dose, repeat if necessary. Max: 2 g/day.

Renal Dose

Renal impairment: Haemodialysis: Additional dose equal to half the usual dose at the end of haemodialysis.

Administration

Should be taken with food. Take during or immediately after meals.

Contra Indications

Blood dyscrasias, organic neurologic disorders, hypersensitivity to 5-nitroimidazole derivatives, porphyria. Lactation, pregnancy (1st trimester).

Precautions

Patient w/ current or a history of blood dyscrasias. Pregnancy (2nd and 3rd trimester). Hepatic and renal impairment. Monitoring Parameters Monitor total and differential leukocyte counts. Closely monitor childn when treatment duration exceeds 3 days. Lactation: discontinue nursing while taking drug & for 3 d after last dose

Pregnancy-Lactation

Pregnancy Available published data from a case-control study and case report with use in pregnant women are insufficient to identify risk of major birth defects, miscarriage or adverse maternal or fetal outcomes; there are risks associated with untreated lower genital tract infections during pregnancy Infertility Based on findings in rodents, therapy may impair fertility in males of reproductive potential; not known whether effects on fertility are reversible Animal data In animal reproduction studies, oral administration of tinidazole to pregnant mice and rats during organogenesis at 6 and 3 times, respectively, the maximum recommended human dose (based on body surface area comparison) showed a slight increase in fetal mortality in rats at highest dose, with no other adverse fetal effects noted in either species Lactation Limited published literature, based on breast milk sampling, reports that drug is present in human milk; there are no reports of adverse effects on breastfed infant and no information on effects on milk production Because of potential for serious adverse reactions, including tumorigenicity, breastfeeding is not recommended during treatment and for 72 hours (based on half-life) after last dose A nursing mother may choose to pump and discard her milk during treatment and for 72 hours after last dose to minimize exposure to breastfeeding infant

Interactions

May potentiate the effects of oral anticoagulants resulting to prolonged prothrombin time.

Adverse Effects

Side effects of Tinidazole : 1-10% Anorexia (2-3%), Constipation (<1%), Dizziness (<1%), Dysgeusia (4-6%), Dyspepsia (1-2%), Headache (<1%), Nausea (3-5%), Vomiting (1-2%), Weakness/fatigue/malaise (1-2%) Frequency Not Defined Ataxia, Candida overgrowth, Convulsions & transient peripheral neuropathy, Numbness & paresthesia, Diarrhea, Darkened urine, Tongue discoloration, Transient leukopenia/neutropenia Potentially Fatal: Hypersensitivity.

Mechanism of Action

Tinidazole, a 5-nitroimidazole derivative w/ antimicrobial actions similar to metronidazole, is active against both protozoa (e.g. Trichomonas vaginalis, Entamoeba histolytica and Giardia lamblia) and obligate anaerobic bacteria. It damages DNA strands or inhibits DNA synthesis in microorganism.