Drug Groups

approved; investigational

Description

A nitroimidazole antitrichomonal agent effective against Trichomonas vaginalis, Entamoeba histolytica, and Giardia lamblia infections. [PubChem]

Indication

For the treatment of trichomoniasis caused by T. vaginalis in both female and male patients. Also for the treatment of giardiasis caused by G. duodenalis in both adults and pediatric patients older than three years of age and for the treatment of intestinal amebiasis and amebic liver abscess caused by E. histolytica in both adults and pediatric patients older than three years of age.

Pharmacology

Tinidazole is a synthetic antiprotozoal agent. Tinidazole demonstrates activity both in vitro and in clinical infections against the following protozoa: Trichomonas vaginalis, Giardia duodenalis (also termed G. lamblia), and Entamoeba histolytica. Tinidazole does not appear to have activity against most strains of vaginal lactobacilli.

Toxicity

There are no reported overdoses with tinidazole in humans. In acute studies with mice and rats, the LD 50 for mice was generally > 3,600 mg/kg for oral administration and was > 2,300 mg/kg for intraperitoneal administration. In rats, the LD 50 was > 2,000 mg/kg for both oral and intraperitoneal administration.

Affected Organisms

Biotransformation

Hepatic, mainly via CYP3A4. Tinidazole, like metronidazole, is significantly metabolized in humans prior to excretion. Tinidazole is partly metabolized by oxidation, hydroxylation and conjugation. Tinidazole is the major drug-related constituent in plasma after human treatment, along with a small amount of the 2-hydroxymethyl metabolite.

Absorption

Rapidly and completely absorbed under fasting conditions. Administration with food results in a delay in T_max of approximately 2 hours and a decline in C_max of approximately 10% and an AUC of 901.6 ± 126.5 mcg hr/mL.

Half Life

Elimination half-life is 13.2 ± 1.4 hours. Plasma half-life is 12 to 14 hours.

Protein Binding

Plasma protein binding of tinidazole is 12%.

Elimination

Tinidazole crosses the placental barrier and is secreted in breast milk. Tinidazole is excreted by the liver and the kidneys.
Tinidazole is excreted in the urine mainly as unchanged drug (approximately 20-25% of the administered dose).
Approximately 12% of the drug is excreted in the feces.

Distribution

* 50 L

References

External Links