Tigan Injection

Generic name: trimethobenzamide hydrochloride
Dosage form: injection
Drug class:Anticholinergic antiemetics

Medically reviewed by Drugs.com. Last updated on Jul 22, 2021.

Injectable

For Intramuscular Use Only

Not for Use in Pediatric Patients

Tigan Injection Description

Chemically, trimethobenzamide hydrochloride (HCl) is N-[p-[2-(dimethylamino)ethoxy]benzyl]-3,4,5-trimethoxybenzamide monohydrochloride. It has a molecular weight of 424.93 and the following structural formula:

Single Dose Vials: Each 2-mL single-dose vial contains 200 mg trimethobenzamide hydrochloride compounded with 1 mg sodium citrate and 0.4 mg citric acid as buffers and pH adjusted to approximately 5.0 with sodium hydroxide.

Multi-Dose Vials: Each mL contains 100 mg trimethobenzamide hydrochloride compounded with 0.45% phenol as preservative, 0.5 mg sodium citrate and 0.2 mg citric acid as buffers and pH adjusted to approximately 5.0 with sodium hydroxide.

Tigan Injection - Clinical Pharmacology

Mechanism of Action

The mechanism of action of Tigan® as determined in animals is obscure, but may involve the chemoreceptor trigger zone (CTZ), an area in the medulla oblongata through which emetic impulses are conveyed to the vomiting center; direct impulses to the vomiting center apparently are not similarly inhibited. In dogs pretreated with trimethobenzamide HCl, the emetic response to apomorphine is inhibited, while little or no protection is afforded against emesis induced by intragastric copper sulfate.

Pharmacokinetics

The pharmacokinetics of trimethobenzamide have been studied in healthy adult subjects. Following administration of 200 mg (100 mg/mL) Tigan IM injection, the time to reach maximum plasma concentration (Tmax) was about half an hour, about 15 minutes longer for Tigan 300 mg oral capsule than an IM injection. A single dose of Tigan 300 mg oral capsule provided a plasma concentration profile of trimethobenzamide similar to Tigan 200 mg IM. The relative bioavailability of the capsule formulation compared to the solution is 100%....