General Information

Tindamax tablets contain the antimicrobial agent tinidazole, a second generation synthetic nitroimidazole. The drug has activity against many species of infectious protozoals, including those which sexually transmitted and water borne. It was designed to be effective in the short term, with treatment usually ranging from just a single dose to as long as 3 days.

Tinidazole tablets are indicated for the treatment of the following protozoal infections

Trichomoniasis caused by T. vaginalis in both male and female patients

Giardiasis caused by G. duodenalis\G. lamblia)

Amebiasis and amebic liver abscess caused by E. histolytica

Tindamax is supplied as an oral tablet at one of two dosing stregths (250 and 500 mg), and is designed to be taken with food. For trichomoniasis and giardiasis, recommended dosage is a single dose of 2 g. For amebiasis/amebic abscess, recommended dosage is 2 g once daily for three days. Pediatric doses should be adjusted by patient weight at 50 mg/kg, up to 2 g total dose.

Clinical Results

Approval of Tindamax for trichomoniasis was based on the combined results of 34 studies involving over 2,800 subjects. 4 blinded, randomized, comparative studies in which the 2 g single oral dose was used assessed efficacy by culture at time points post-treatment ranging from one week to one month. Reported cure rates ranged from 92% (37/40) to 100% (65/65) (n=172 total subjects). 4 blinded, randomized, comparative studies assessed efficacy by wet mount between 7-14 days post-treatment. Reported cure rates ranged from 80% (8/10) to 100% (16/16) (n=116 total subjects). In these studies, tinidazole was superior to placebo and comparable to other anti-trichomonal drugs. The single oral 2 g tinidazole dose was also assessed in 4 open label trials in men (one comparative to metronidazole and 3 single arm studies). Parasitological evaluation of the urine was performed both pre- and post-treatment, and reported cure rates ranged from 83% (25/30) to 100% (80/80) (n=142 total subjects).

Approval for giardias was based on 19 studies involving 1,600 adult and pediatric subjects. In eight controlled studies involving a total of 619 subjects, of whom 299 were given the 2 g (50 mg/kg in pediatric patients) single oral dose of tinidazole, reported cure rates ranged from 80% (40/50) to 100% (15/15). In three of these trials where the comparator was 2 to 3 days of various doses of metronidazole, reported cure rates for metronidazole were 76% (19/25) to 93% (14/15). Data comparing a single 2 g dose of tinidazole to the recommended 5-7 days of metronidazole are limited.

Approval for amebiasis was based on 26 reported studies involving over 1,400 subjects. The majority of studies investigated the 2 g daily oral dose for 3 days. In four randomized, controlled studies (1 investigator single-blind, 3 open-label)using this dose, reported cure rates after three days among 220 subjects ranged from 86% (25/29) to 93% (25/27). Approval for amebic liver abscess was based on 18 reported studies treating a total of 470 subjects. Subjects in these studies received the 2 g oral dose for 2-5 days. In 7 randomized, controlled studies (1 double-blind, 1 single-blind, 5 open-label) at that dose, (with additional aspiration of the liver abscess when clinically necessary), reported cure rates among 133 subjects ranged from 81% (17/21) to 100% (16/16); 4 of these studies utilized at least 3 days of tinidazole.

Mechanism of Action

Tindamax is a second generation small-molecule antiprotozoal agent. While the precise mechanism of action is unknown, cell extracts from Trichomonas have been shown to reduce the molecule's nitro group, producing cytotoxic free radicals. The mechanism of action against Giardia and Entamoeba species is unknown, but activity has been confirmed both in vitro and in vivo.

Literature References

Manes G, Balzano A. Tinidazole: from protozoa to Helicobacter pylori--the past, present and future of a nitroimidazole with peculiarities. Expert Review of Anti-infective Therapy. 2004 Oct;2(5):695-705

Hager WD. Treatment of metronidazole-resistant Trichomonas vaginalis with tinidazole: case reports of three patients. Sexually Transmitted Diseases. 2004 Jun;31(6):343-5

Wright JM, Dunn LA, Upcroft P, Upcroft JA. Efficacy of antigiardial drugs. Expert Opinions on Drug Safety. 2003 Nov;2(6):529-41