Tinidazole (Tindamax): Drug Information

Tinidazole is a synthetic nitroimidazole, an antiprotozoal, antibacterial agent used to treat certain types of vaginal infections and also used to treat certain types of parasite infections (giardiasis, amebiasis).

Class: Synthetic nitroimidazole
Use: Antiprotozoal and antibacterial agent
Pregnancy Category: C

Pharmacological Properties

Active against protozoa: Trichomonas vaginalis, Entamoeba histolytica, Giardia lamblia
Active against anaerobic bacteria including Helicobacter pylori, Gardnerella vaginalis, Bacteroides spp., Clostridium spp., Eubacterium spp., Veillonella spp.
Mechanism: Intracellular reduction under anaerobic conditions → DNA strand breakage → inhibition of nucleic acid synthesis → microbial death

Therapeutic Indications

Helicobacter pylori eradication (combined with antibiotics & acid suppression)
Anaerobic infections: peritonitis, abscesses, gynecological infections (endometritis, tubo-ovarian abscess)
Bacterial septicemia, postoperative wound infections
Skin, soft tissue infections
Respiratory tract infections: pneumonia, empyema, lung abscess
Nonspecific vaginitis
Acute ulcerative gingivitis
Urogenital trichomoniasis (both sexes)
Giardiasis, intestinal amoebiasis, amoebic liver involvement
Prophylaxis: Prevent post-operative infections from anaerobes in GI and gynecological surgery

Contraindications & Warnings

Contraindicated in:
- Patients with blood dyscrasias history
- Neurological disorders (risk of dizziness, vertigo, ataxia, incoordination)
- First trimester pregnancy and lactation
- Allergy to tinidazole or related nitroimidazoles
Avoid alcohol during treatment and for 72 hours post-treatment (risk of disulfiram-like reaction)
Monitor closely for neurological symptoms; discontinue if they appear
Potential mutagenicity—prolonged use should be cautious

Side Effects

Blood: leukopenia
Nervous system: dizziness, headache, ataxia, convulsions, paresthesia, peripheral neuropathy
Gastrointestinal: nausea, vomiting, anorexia, stomatitis, glossitis, diarrhea, metallic taste
Skin: rash, pruritus, urticaria, angioneurotic edema (rare severe hypersensitivity)
Renal: dark urine
General: fever, tiredness

Drug Interactions

Alcohol: disulfiram-like reaction
Anticoagulants (e.g., warfarin): may potentiate effect, monitor INR closely
Cholestyramine: decreases tinidazole absorption
Cimetidine, ketoconazole: may increase tinidazole levels
Cyclosporine, tacrolimus: increased serum levels
Disulfiram: combined toxicity risk
Fluorouracil: decreased clearance
Lithium: increased levels
Oxytetracycline: diminished tinidazole effect
Phenobarbital, phenytoin, rifampin: increased metabolism, decreased levels

Pharmacokinetics

Oral absorption: rapid, peak plasma in 1–3 hours
Protein binding: low (10–20%)
Half-life: 12–14 hours
Widely distributed, intracellular concentrations approximate plasma levels

Dosage and Administration

Oral administration with food to minimize gastric irritation
Tablets may be crushed and mixed with artificial cherry syrup for those unable to swallow

Specific Dosages:

Indication	Adult Dose	Pediatric Dose
H. pylori eradication	500 mg twice daily (7 days), with omeprazole + clarithromycin	Not specified
Anaerobic infections	2 g first day, then 1 g daily or 500 mg twice daily (≥7 days)	Monitor if prolonged
Nonspecific vaginitis	2 g single dose	—
Ulcerative gingivitis	2 g single dose	—
Urogenital trichomoniasis	2 g single dose	50-75 mg/kg body weight
Giardiasis	2 g single dose	50-70 mg/kg body weight
Intestinal amoebiasis	2 g daily for 2-3 days	50-70 mg/kg for 3 days
Amoebic liver abscess	1.5-2 g single dose daily for 3-6 days (4.5-12 g total)	50-60 mg/kg/day for 5 days
Postoperative prophylaxis	2 g single dose ~12 hrs before surgery	Not established (<12 yrs)