Trimeprazine

Absorption

Well absorbed in the digestive tract.

Toxicity

Symptoms of overdose clumsiness or unsteadiness, seizures, severe drowsiness, flushing or redness of face, hallucinations, muscle spasms (especially of neck and back), restlessness, shortness of breath, shuffling walk, tic-like (jerky) movements of head and face, trembling and shaking of hands, and insomnia.

Originator

Temaril,SKF,US,1958

The Uses of Trimeprazine

Trimeprazine is used for treating itching during dermatitis of both allergic and nonallergic origin.

The Uses of Trimeprazine

antipruritic

Indications

Used to prevent and relieve allergic conditions which cause pruritus (itching) and urticaria (some allergic skin reactions).

Background

A phenothiazine derivative that is used as an antipruritic.

Definition

ChEBI: Trimeprazine is a member of phenothiazines.

Manufacturing Process

95% sodamide (2.77 grams) is added to a solution of phenthiazine (9.6 grams) in xylene (140 cc) at a temperature of 130°C and the mixture is heated with reflux for 2 hours.
A 0.61 N solution (90 cc) of 1-chloro-2-methyl-3-dimethylaminopropane in xylene is then added over 50 minutes and heating with reflux is continued for 20 hours. After cooling, the mixture is treated with water (40 cc) and N methanesulfonic acid (70 cc). The aqueous layer is washed with ether, treated with aqueous sodium hydroxide (density = 1.33; 10 cc) and extracted with ether.
The extract is dried over potassium carbonate and evaporated and the residue is distilled in vacuo. 3-(10-phenthiazinyl)-2-methyl-1-dimethylaminopropane (12.6 grams) is collected, distilling between 150° and 175°C under a pressure of about 0.3 mm Hg. By dissolving this base in acetone and adding ethereal hydrogen chloride, a hydrochloride is obtained, MP 216° to 217°C.

brand name

Temaril (Allergan).

Therapeutic Function

Antipruritic

Pharmacokinetics

Trimeprazine (also known as Alimemazine) is a tricyclic antihistamine, similar in structure to the phenothiazine antipsychotics, but differing in the ring-substitution and chain characteristics. Trimeprazine is in the same class of drugs as chlorpromazine (Thorazine) and trifluoperazine (Stelazine); however, unlike the other drugs in this class, trimeprazine is not used clinically as an anti-psychotic. It acts as an anti-histamine, a sedative, and an anti-emetic (anti-nausea). Trimeprazine is used principally as an anti-emetic, to prevent motion sickness or as an anti-histamine in combination with other medications in cough and cold preparations. Tricyclic antihistamines are also structurally-related to the tricyclic antidepressants, explaining the antihistaminergic adverse effects of these two drug classes and also the poor tolerability profile of tricyclic H1-antihistamines.

Metabolism

Hepatic