Tinidazole Tablets

Trichomoniasis

Tinidazole is indicated for the treatment of trichomoniasis caused by Trichomonas vaginalis. The organism should be identified by appropriate diagnostic procedures. Because trichomoniasis is a sexually transmitted disease with potentially serious sequelae, partners of infected patients should be treated simultaneously in order to prevent re-infection [see Clinical Studies(14.1)].

Giardiasis

Tinidazole is indicated for the treatment of giardiasis caused by Giardia duodenalis (also termed G. lamblia) in both adults and pediatric patients older than three years of age [see Clinical Studies (14.2)].

Amebiasis

Tinidazole is indicated for the treatment of intestinal amebiasis and amebic liver abscess caused by Entamoeba histolytica in both adults and pediatric patients older than three years of age. It is not indicated in the treatment of asymptomatic cyst passage [see Clinical Studies (14.3,14.4)].

Bacterial Vaginosis

Tinidazole is indicated for the treatment of bacterial vaginosis (formerly referred to as Haemophilus vaginitis, Gardnerella vaginitis, nonspecific vaginitis, or anaerobic vaginosis) in non-pregnant women [see Use in Specific Populations (8.1)and Clinical Studies (14.5)].

Other pathogens commonly associated with vulvovaginitis such as Trichomonas vaginalis, Chlamydia trachomatis, Neisseria gonorrhoeae, Candida albicans and Herpes simplex virus should be ruled out.

To reduce the development of drug-resistant bacteria and maintain the effectiveness of Tinidazole Tablets and other antibacterial drugs, Tinidazole Tablets should be used only to treat or prevent infections that are proven or strongly suspected to be caused by susceptible bacteria. When culture and susceptibility information are available, they should be considered in selecting or modifying antibacterial therapy. In the absence of such data, local epidemiology and susceptibility patterns may contribute to the empiric selection of therapy.

The use of tinidazole is contraindicated:

• In patients with a previous history of hypersensitivity to tinidazole or other nitroimidazole derivatives. Reported reactions have ranged in severity from urticaria to Stevens-Johnson syndrome [see Adverse Reactions (6.1,6.2)].
• During first trimester of pregnancy [see Use in Specific Populations (8.1)].
• In nursing mothers: Interruption of breast-feeding is recommended during tinidazole therapy and for 3 days following the last dose [see Use in Specific Populations (8.3)].

Clinical Studies Experience

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice.

Among 3669 patients treated with a single 2 g dose of tinidazole, in both controlled and uncontrolled trichomoniasis and giardiasis clinical studies, adverse reactions were reported by 11.0% of patients. For multi-day dosing in controlled and uncontrolled amebiasis studies, adverse reactions were reported by 13.8% of 1765 patients. Common (≥ 1% incidence) adverse reactions reported by body system are as follows. (Note: Data described in Table 1 below are pooled from studies with variable designs and safety evaluations.)

Other adverse reactions reported with tinidazole include:

Central Nervous System: Two serious adverse reactions reported include convulsions and transient peripheral neuropathy including numbness and paresthesia [see Warnings and Precautions (5.1)]. Other CNS reports include vertigo, ataxia, giddiness, insomnia, drowsiness.

Gastrointestinal: tongue discoloration, stomatitis, diarrhea

Hypersensitivity: urticaria, pruritis, rash, flushing, sweating, dryness of mouth, fever, burning sensation, thirst, salivation, angioedema

Renal: darkened urine

Cardiovascular: palpitations

Hematopoietic: transient neutropenia, transient leukopenia

Other: Candida overgrowth, increased vaginal discharge, oral candidiasis, hepatic abnormalities including raised transaminase level, arthralgias, myalgias, and arthritis.

Rare reported adverse reactions include bronchospasm, dyspnea, coma, confusion, depression, furry tongue, pharyngitis and reversible thrombocytopenia.

Adverse Reactions in Pediatric Patients: In pooled pediatric studies, adverse reactions reported in pediatric patients taking tinidazole were similar in nature and frequency to adult findings including nausea, vomiting, diarrhea, taste change, anorexia, and abdominal pain.

Bacterial vaginosis: The most common adverse reactions in treated patients (incidence > 2%), which were not identified in the trichomoniasis, giardiasis and amebiasis studies, are gastrointestinal: decreased appetite, and flatulence; renal: urinary tract infection, painful urination, and urine abnormality; and other reactions including pelvic pain, vulvo-vaginal discomfort, vaginal odor, menorrhagia, and upper respiratory tract infection [see Clinical Studies (14.5)]

Postmarketing Experience

The following adverse reactions have been identified and reported during post-approval use of Tinidazole Tablets. Because the reports of these reactions are voluntary and the population is of uncertain size, it is not always possible to reliably estimate the frequency of the reaction or establish a causal relationship to drug exposure.

Severe acute hypersensitivity reactions have been reported on initial or subsequent exposure to tinidazole. Hypersensitivity reactions may include urticaria, pruritis, angioedema, Stevens-Johnson syndrome and erythema multiforme.

There are no reported overdoses with tinidazole in humans.

Treatment of Overdosage: There is no specific antidote for the treatment of overdosage with tinidazole; therefore, treatment should be symptomatic and supportive. Gastric lavage may be helpful. Hemodialysis can be considered because approximately 43% of the amount present in the body is eliminated during a 6-hour hemodialysis session.

Trichomoniasis

Tinidazole (2 g single oral dose) use in trichomoniasis has been well documented in 34 published reports from the world literature involving over 2,800 patients treated with tinidazole. In four published, blinded, randomized, comparative studies of the 2 g tinidazole single oral dose where efficacy was assessed 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). In four published, blinded, randomized, comparative studies where efficacy was assessed by wet mount between 7 to 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 four 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).

Giardiasis

Tinidazole (2 g single dose) use in giardiasis has been documented in 19 published reports from the world literature involving over 1,600 patients (adults and pediatric patients). In eight controlled studies involving a total of 619 subjects of whom 299 were given the 2 g x 1 day (50 mg/kg x 1 day in pediatric patients) 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 usually recommended 5 to 7 days of metronidazole are limited.

Intestinal Amebiasis

Tinidazole use in intestinal amebiasis has been documented in 26 published reports from the world literature involving over 1,400 patients. Most reports utilized tinidazole 2 g/day x 3 days. In four published, randomized, controlled studies (1 investigator single-blind, 3 open-label) of the 2 g/day x 3 days oral dose of tinidazole, reported cure rates after 3 days of therapy among a total of 220 subjects 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 from the world literature involving over 470 patients. Most reports utilized tinidazole 2 g/day x 2 to 5 days. In seven published, randomized, controlled studies (1 double-blind, 1 single-blind, 5 open-label) of the 2 g/ day x 2 to 5 days oral dose of tinidazole accompanied by aspiration of the liver abscess when clinically necessary, reported cure rates among 133 subjects ranged from 81% (17/21) to 100% (16/16). Four of these studies utilized at least 3 days of tinidazole

Bacterial Vaginosis

A randomized, double-blind, placebo-controlled clinical trial in 235 non-pregnant women was conducted to evaluate the efficacy of tinidazole for the treatment of bacterial vaginosis. A clinical diagnosis of bacterial vaginosis was based on Amsel’s criteria and defined by the presence of an abnormal homogeneous vaginal discharge that (a) has a pH of greater than 4.5, (b) emits a “fishy” amine odor when mixed with a 10% KOH solution, and (c) contains ≥ 20% clue cells on microscopic examination. Clinical cure required a return to normal vaginal discharge and resolution of all Amsel’s criteria. A microbiologic diagnosis of bacterial Vaginosis was based on Gram stain of the vaginal smear demonstrating (a) markedly reduced or absent Lactobacillus morphology, (b) predominance of Gardnerella morphotype, and (c) absent or few white blood cells, with quantification of these bacterial morphotypes to determine the Nugent score, where a score ≥ 4 was required for study inclusion and a score of 0 to 3 considered a microbiologic cure. Therapeutic cure was a composite endpoint, consisting of both a clinical cure and microbiologic cure. In patients with all four Amsel’s criteria and with a baseline Nugent score ≥ 4, tinidazole oral tablets given as either 2 g once daily for 2 days or 1 g once daily for 5 days demonstrated superior efficacy over placebo tablets as measured by therapeutic cure, clinical cure, and a microbiologic cure.

p-values for both Tinidazole Tablets regimens vs. placebo for therapeutic, clinical and Nugent score cure rates for both 2 and 5 days < 0.001

The therapeutic cure rates reported in this clinical study conducted with Tinidazole Tablets were based on resolution of 4 out of 4 Amsel’s criteria and a Nugent score of < 4. The cure rates for previous clinical studies with other products approved for bacterial vaginosis were based on resolution of either 2 or 3 out of 4 Amsel’s criteria. At the time of approval for other products for bacterial vaginosis, there was no requirement for a Nugent score on Gram stain, resulting in higher reported rates of cure for bacterial vaginosis for those products than for those reported here for tinidazole.

Tinidazole Tablets 250 mg are yellow, round, scored tablets with 207 debossed on one side, supplied in bottles with child-resistant caps as:

NDC 52682-043-08 Bottle of 40

Tinidazole Tablets 500 mg are yellow, oval, scored tablets with 208 debossed on one side, supplied in bottles with child-resistant caps as:

NDC 52682-044-07 Bottle of 20
NDC 52682-044-06 Bottle of 60

Storage: Store at controlled room temperature 20 to 25°C (68 to 77°F); excursions permitted to 15 to 30°C (59 to 86°F) [see USP]. Protect contents from light.