Tinidazole

Products

Tinidazole (Fasigyn, 500 mg) is no longer available as a finished drug in many countries. It had been approved since 1973. Drugs containing the active ingredient can be imported from abroad or prepared in a pharmacy as an extemporaneous preparation. A substitute is metronidazole (Flagyl, generic).

Structure and properties

Tinidazole (C8H13N3O4S, Mr = 247.3 g/mol) exists as a white to pale yellow crystalline powder that is practically insoluble in water. It is a 2-methyl-5-nitroimidazole. Tinidazole is structurally closely related to metronidazole.

Effects

Tinidazole (ATC J01XD02, ATC P01AB02) has bactericidal properties against anaerobic bacteria (eg, ) and is antiparasitic against protozoa. It has a half-life of about 12 to 14 hours. The effects are based, among other things, on the formation of nitroradicals, which bind to the DNA of the pathogens and cause damage there. Tinidazole is a prodrug.

Indications

For treatment of infections with anaerobic bacteria or protozoa, e.g., amebiasis, trichomoniasis, giardiasis, and bacterial vaginosis.

Contraindications

  • Hypersensitivity
  • Severe damage to the brain or nervous system.
  • Disorders of hematopoiesis
  • Pregnancy and lactation

Full precautions can be found in the drug label.

Dosage

According to the SmPC. Tablets are taken with food. For most indications, a single dose is sufficient, usually 2000 mg (4 tablets).

Interactions

Tinidazole is a substrate of CYP3A and corresponding drug-drug interactions are possible. Alcohol should not be consumed for up to 3 days after the last dose because it may result in an intolerance reaction with symptoms such as abdominal cramps, vomiting, and facial flushing.

Adverse effects

Possible adverse effects include:

  • Gastrointestinal symptoms such as nausea, vomiting, loss of appetite, diarrhea, abdominal pain, metallic or bitter taste in the mouth, hairy tongue
  • Hypersensitivity reactions, skin rash.
  • Central disorders: Headache, fatigue, drowsiness, dizziness, movement disorders, sensory disturbances, neuropathy, convulsions.
  • Dark urine

Mutagenic properties have been observed in animal experiments.