T-zol

• Approved indications:
• Amebiasis: Treatment of invasive intestinal and extraintestinal amoebiasis caused by Entamoeba histolytica.
• Giardiasis: Treatment of infections caused by Giardia lamblia.
• Trichomoniasis: Treatment of Trichomonas vaginalis infections in both men and women.
• Bacterial vaginosis: As part of combination therapy for bacterial vaginosis caused by anaerobic bacteria.
• Anaerobic bacterial infections: Including infections caused by susceptible anaerobes (e.g., Bacteroides fragilis).
• Helicobacter pylori eradication: As part of combination regimens (off-label use).
• Important off-label and clinically accepted uses:
• Pelvic inflammatory disease (PID): As part of combination regimens targeting anaerobic and protozoal pathogens.
• Giardiasis in pediatric populations: Accepted in certain countries with adjusted dosing.
• Other protozoal infections: Occasionally used for infections like Balantidium coli and Trichomonas tenax in some clinical scenarios.

• Adults:
• Amebiasis, giardiasis, trichomoniasis: 2 g orally as a single dose.
• For some infections (e.g., bacterial vaginosis or mixed anaerobic infections), dosage may be 500 mg twice daily for 5–7 days.
• Pediatrics:
• Dosing varies by indication and weight; typically 50 mg/kg divided doses, max 2 g daily, duration 3–5 days.
• Elderly:
• Same as adults; no specific dose adjustment but monitor for side effects.
• Renal impairment:
• Use with caution in severe renal impairment; no standard dose adjustment, but extended dosing intervals may be considered.
• Hepatic impairment:
• Use cautiously; metabolism is hepatic. No specific dose adjustment guidelines but monitor liver function.
• Administration:
• Oral route only. Take with food to reduce gastrointestinal upset. Avoid alcohol during and for at least 72 hours after treatment.

Tinidazole is a nitroimidazole antimicrobial agent. After entering anaerobic protozoal and bacterial cells, it undergoes reduction of its nitro group by intracellular electron transport proteins. This reduction forms reactive nitro radicals that damage DNA by inducing strand breakage and destabilization, ultimately inhibiting nucleic acid synthesis. This leads to cell death of susceptible anaerobic protozoa and bacteria.

• Absorption: Rapid and almost complete oral absorption; bioavailability close to 100%.
• Distribution: Widely distributed in body tissues and fluids including liver, kidneys, lungs, vagina, and cerebrospinal fluid. Volume of distribution approx. 0.5–0.6 L/kg.
• Protein binding: Approximately 12–20%.
• Metabolism: Extensively metabolized in the liver mainly via oxidation and conjugation pathways; no significant CYP450 interaction.
• Elimination half-life: Approximately 12–14 hours.
• Excretion: Primarily renal (about 20–30% unchanged drug), with remainder excreted in feces and as metabolites.

• Pregnancy: Classified as FDA Pregnancy Category B. Animal studies have shown no teratogenicity; limited controlled human data suggest safety but use only if clearly needed.
• Lactation: Excreted into breast milk in small amounts; caution advised during breastfeeding due to potential adverse effects in the infant. Consider alternative feeding or temporary discontinuation.

• Primary class: Antiprotozoal and Antibacterial agent
• Subclass: Nitroimidazole derivative

• Known hypersensitivity to tinidazole or other nitroimidazoles (e.g., metronidazole).
• First trimester of pregnancy (relative contraindication; avoid if possible).
• Use with disulfiram within the past two weeks (due to risk of severe reactions).
• Severe hepatic impairment without close monitoring.

• Avoid alcohol during treatment and for 72 hours after to prevent disulfiram-like reaction (flushing, nausea, vomiting, tachycardia).
• Use with caution in patients with hepatic impairment.
• May cause peripheral neuropathy, especially with prolonged use. Monitor neurological symptoms.
• CNS effects: dizziness, seizures, encephalopathy reported rarely; monitor especially in patients with predisposing factors.
• Blood dyscrasias (leukopenia, thrombocytopenia) reported rarely; monitor blood counts during prolonged therapy.
• Use caution in patients with history of blood disorders or CNS disease.

Common:

• Gastrointestinal: nausea, vomiting, abdominal discomfort, metallic or bitter taste.
• CNS: headache, dizziness, fatigue.

Less common:

• Dry mouth, glossitis, diarrhea.
• Skin reactions: rash, pruritus.

Serious but rare:

• Peripheral neuropathy (numbness, tingling).
• Seizures or encephalopathy.
• Hypersensitivity reactions including Stevens-Johnson syndrome (very rare).
• Blood disorders (leukopenia, neutropenia, thrombocytopenia).

• Alcohol: Concurrent use causes disulfiram-like reaction. Avoid alcohol during and for 72 hours after treatment.
• Warfarin and other oral anticoagulants: May potentiate anticoagulant effect; monitor INR closely.
• Lithium: May increase lithium levels; monitor lithium concentrations.
• Phenytoin and phenobarbital: May decrease tinidazole levels due to enzyme induction.
• No significant CYP450 inhibition or induction noted.

• Tinidazole continues to be preferred over metronidazole in some regions for shorter-course treatment of protozoal infections due to better tolerability and compliance.
• Recent guidelines emphasize the avoidance of alcohol due to severe disulfiram-like reactions.
• WHO Essential Medicines List includes tinidazole for treatment of amebiasis and trichomoniasis.
• No significant changes in dosing recommendations; caution reinforced in hepatic impairment and during pregnancy.

• Store at 20°C to 25°C (room temperature).
• Protect from moisture and light; keep in tightly closed container.
• Do not freeze.
• Keep out of reach of children.