Tindamax (tinidazole) Clinical Studies for BV and Trichomoniasis

Note: This page is for basic patient education only. For detailed information about Tindamax, please consult the full Prescribing Information.

Bacterial vaginosis

To evaluate its effectiveness for treating BV, Tindamax^® was tested in 235 non-pregnant women during a randomized, double-blind, placebo-controlled clinical trial (a trial in which neither the researchers nor the subjects know which patients are taking the active medication or the placebo until after the study).

Clinical Diagnosis and Cure

Patients who participated in this study were clinically diagnosed using Amsel's criteria, meaning that their vaginal discharge:

Was abnormal and homogeneous
Had a pH greater than 4.5
Gave off a "fishy" odor when mixed with a 10% potassium hydroxide (KOH) solution
Contained at least 20% clue cells (vaginal skin cells that have an unusual appearance when examined under a microscope because they are covered with bacteria)

Patients were considered clinically cured upon completion of the study if their vaginal discharge returned to normal and it no longer met these 4 criteria.

Microbiologic Diagnosis and Cure

In addition to receiving a clinical diagnosis, study participants were diagnosed with BV using a Gram stain of their vaginal fluid. This lab test demonstrated:

Reduced or missing Lactobacillus bacteria
Predominance of Gardnerella bacteria
Few, if any, white blood cells, and quantification of bacteria to determine a Nugent score (a score ranging from 0 to 10, based on finding certain types and amounts of bacteria)

A Nugent score of 4 or greater was required for patients to be included in the study, and a score of 0 to 3 was considered a microbiologic cure.

Therapeutic Cure

In this trial, treatment was considered effective if it resulted in both a clinical cure (resolution of all 4 Amsel's criteria) and a microbiologic cure (Nugent score of 0 to 3).

In patients who had all 4 Amsel's criteria and a Nugent score of 4 or greater before the study, tinidazole oral tablets given as either 2 g once daily for 2 days or 1 g once daily for 5 days were proven effective over placebo tablets, as measured by therapeutic cure, clinical cure, and a microbiologic cure.

Efficacy of Tindamax^® in the treatment of bacterial vaginosis in a randomized, double-blind, double-dummy, placebo-controlled trial:
Modified intent-to-treat population^† *(n=227)*
Outcome	Tindamax^® 1 g × 5 days	Tindamax^® 2 g × 2 days	Placebo
Therapeutic Cure
Percent cure	36.8%	27.4%	5.1%
Difference^‡	31.7%	22.3%
97.5% CI^§	(16.8, 46.6)	(8.0, 36.6)
Clinical Cure
Percent cure	51.3%	35.6%	11.5%
Difference^‡	39.8%	24.1%
97.5% CI^§	(23.3, 56.3)	(7.8, 40.3)
Nugent Score Cure
Percent cure	38.2%	27.4%	5.1%
Difference^‡	33.1%	22.3%
97.5% CI^§	(18.1, 48.0)	(8.0, 36.6)
n	76	73	78
† Modified Intent-to-Treat defined as all patients randomized with a baseline Nugent score of at least 4 ‡ Difference in cure rates (Tindamax^®-placebo) § CI: confidence interval p-values for both Tindamax^® regimens vs. placebo for therapeutic, clinical and Nugent score cure rates for both 2 and 5 days <0.001			Table 1

The therapeutic cure rates reported in this clinical study were based on resolution of 4 out of 4 Amsel's criteria and a Nugent score of less than 4. However, the cure rates for previous clinical studies with other products approved for BV were based on resolution of either 2 or 3 out of 4 Amsel's criteria. At the time of approval for those other products, there was no requirement for a Nugent score on Gram stain. This means that reported rates of effectiveness for those products — higher than those reported here for tinidazole — may have been lower if they had used the more stringent criteria used in the tinidazole trial.

Trichomoniasis

Tinidazole (2 g single oral dose) use in treating trichomoniasis has been well documented in 34 published reports worldwide, involving over 2,800 patients.

In 4 published studies of the 2 g tinidazole single oral dose, its effectiveness was assessed by culture (a lab test analyzing bacterial growth) one week to one month after treatment. Reported cure rates for these studies ranged from 92% (37/40) to 100% (65/65) among 172 subjects.

At least 4 published studies evaluated tinidazole's effectiveness by wet mount (placing a sample of vaginal fluid on a slide and examining it under a microscope) between 7 and 14 days after treatment. Reported cure rates among 116 participants ranged from 80% (8/10) to 100% (16/16).

In all of these studies, tinidazole was superior to a placebo and comparable to other drugs used for treating trichomoniasis.

The single oral 2 g tinidazole dose was also tested in 4 trials in men. The patients' urine was tested for Trichomonas parasites before and after treatment, and reported cure rates ranged from 83% (25/30) to 100% (80/80) among 142 patients.

Giardiasis

Tinidazole (2 g single dose) use for treating giardiasis has been documented in 19 published reports worldwide, involving over 1,600 adult and pediatric patients.

In 8 controlled studies that included 619 subjects, 299 were given the 2 g once a day (50 mg/kg once a day for children) oral dose of tinidazole. Their reported cure rates ranged from 80% (40/50) to 100% (15/15).

Intestinal amebiasis

Tinidazole use in intestinal amebiasis has been documented in 26 published reports, involving over 1,400 patients worldwide. Most reports used tinidazole 2 g/day for 3 days.

In 4 published studies of the 2 g per day for 3 days oral dose of tinidazole, reported cure rates among 220 subjects after 3 days ranged from 86% (25/29) to 93% (25/27).

Amebic liver abscess

Tinidazole use in amebic liver abscess has been documented in 18 published reports involving over 470 patients. Most reports used tinidazole 2 g/day for 2 to 5 days.

In 7 published studies of this oral dose of tinidazole, accompanied by aspiration of the liver abscess (removing fluid from the infected area) when necessary, the reported cure rates among 133 subjects ranged from 81% (17/21) to 100% (16/16). Four of these studies used at least 3 days of tinidazole.

Important Safety Information

WARNING: POTENTIAL RISK FOR CARCINOGENICITY

Carcinogenicity has been seen in mice and rats treated chronically with metronidazole, another nitroimidazole agent. Although such data have not been reported for tinidazole, the two drugs are structurally related and have similar biologic effects. Its use should be reserved for the conditions described in INDICATIONS AND USAGE.

Contraindications

Prior history of hypersensitivity to tinidazole or other nitroimidazole derivatives
First trimester of pregnancy
Nursing mothers, unless breast-feeding is interrupted during tinidazole therapy and for 3 days following the last dose

Warnings and Precautions

Seizures and neuropathy have been reported. Discontinue Tindamax if abnormal neurologic signs develop
Vaginal candidiasis may develop with Tindamax and require treatment with an antifungal agent
Use Tindamax with caution in patients with blood dyscrasias. Tindamax may produce transient leukopenia and neutropenia

Adverse Reactions

Most common adverse reactions for a single 2 g dose of tinidazole (incidence >1%) are metallic/bitter taste, nausea, weakness/fatigue/malaise, dyspepsia/cramps/epigastric discomfort, vomiting, anorexia, headache, dizziness and constipation. To report SUSPECTED ADVERSE REACTIONS, contact Mission Pharmacal Company at 1-800-298-1087 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch

This material is intended to provide basic information. Patients should discuss all medical advice, diagnosis, and treatment with their healthcare provider.

Please see full Prescribing Information