tinidazole
Brand: Tindamax
Prototype: metronidazole
Drug Class: nitroimidazole antibiotic/antiprotozoal
Drug Family: antibiotic
Subclass: second-generation nitroimidazole
Organ Systems: infectious-diseasegastrointestinal
Mechanism of Action
Prodrug activated by intracellular nitroreductases under anaerobic conditions; reactive nitroradicals disrupt DNA helical structure and strand breakage; bactericidal against anaerobes and cidal/static for protozoa.
DNA (nitro group reduced to reactive radicals)
Indications
- bacterial vaginosis
- trichomoniasis
- giardiasis
- amebiasis (intestinal and amebic liver abscess)
- H. pylori eradication (alternative)
Contraindications
- nitroimidazole hypersensitivity
- first trimester pregnancy
- nursing (discontinue breastfeeding during and 3 days after therapy)
Adverse Effects
Common
- metallic taste
- nausea
- GI upset
- headache
Serious
- seizures
- peripheral neuropathy (with prolonged use)
- disulfiram-like reaction with alcohol
Pharmacokinetics (ADME)
| Absorption | ~100% oral bioavailability |
| Distribution | widely distributed including CSF; crosses placenta |
| Metabolism | hepatic (CYP3A4) |
| Excretion | renal (20–25%) and fecal |
| Half-life | 12–14 hours |
| Onset | rapid |
| Peak | 1–3 hours |
| Duration | once-daily dosing for most indications |
| Protein Binding | 12% |
| Vd | moderate |
Drug Interactions
| Drug / Agent | Mechanism | Severity |
|---|---|---|
| alcohol | disulfiram-like reaction (flushing, vomiting, tachycardia); avoid during and 3 days after therapy | major |
| warfarin | CYP3A4 inhibition increases warfarin effect; enhanced INR | major |
| lithium | reduced lithium clearance; toxicity risk | major |
Nursing Considerations
- Instruct patient to absolutely avoid alcohol during therapy and for 3 days after the last dose; even small amounts can cause severe disulfiram-like reaction.
- Tinidazole has a longer half-life than metronidazole, enabling shorter treatment courses (single-dose or 2-day treatment for many indications).
- Administer with food to reduce GI side effects; a single 2-gram dose is often used for trichomoniasis and giardiasis.
- Assess for baseline neurological symptoms; peripheral neuropathy risk with prolonged use.
Clinical Pearls
- Tinidazole's longer half-life enables single-dose or once-daily therapy for most indications, improving adherence compared to the multiple-daily-dose metronidazole regimens.
- For trichomoniasis, both partners must be treated simultaneously regardless of symptoms to prevent ping-pong reinfection.
Safety Profile
Pregnancy avoid
Lactation avoid
Renal Adjustment Not required
Hepatic Adjustment Required
TDM Not required
Concordance Terms
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