Promethazine hydrochloride

Chemical properties

White Solid

The Uses of Promethazine hydrochloride

Promethazine hydrochloride is used as antihistamine; antiemetic; central nervous system depressant; sedative; anticholinergic; antiserotoninergic; local anesthetic; in the treatment of motion sickness, cough linctuses, nausea, and allergic conditions; used to control Parkinsonian symptoms and as central nervous system depressant; in pills, syrup, injections and suppositories.

The Uses of Promethazine hydrochloride

Antihistaminic, antiemetic, CNS depressant

The Uses of Promethazine hydrochloride

stool softener

The Uses of Promethazine hydrochloride

For the treatment of allergic disorders, and nausea/vomiting.

The Uses of Promethazine hydrochloride

Promethazine is a first generation histamine H1 receptor antagonist (Ki = 2.6 nM) whose antihistamine activity has been reported in guinea pigs and mice at ED50 values of 0.43 and 5.9 mg/kg, respectively. Promethazine can penetrate the CNS, depressing central H1 receptor activity, which may relate to its sedative properties, and can also inhibit muscarinic acetylcholine receptors (Ki = 22 nM). Furthermore, 32 mg/kg promethazine demonstrates antiemetic effects in ferret models of motion sickness or chemotherapy-induced nausea.

What are the applications of Application

Promethazine Hydrochloride is an antagonist of the histamine H1-receptor

Definition

ChEBI: The hydrochloride salt of promethazine.

brand name

Phenergan (Wyeth).

General Description

Odorless white to faint yellow crystalline powder. Bitter taste. A 10% solution in water has a pH of 3.5-5.0.

General Description

Promethazine hydrochloride,(±)10-[2-(dimethylamino)-propyl]phenothiazinemonohydrochloride (Phenergan), occurs as a white tofaint yellow crystalline powder that is very soluble in water,in hot absolute alcohol, and in chloroform. Its aqueous solutionsare slightly acid to litmus.

Air & Water Reactions

Slowly oxidizes in air, acquiring a blue color. Also turns blue on exposure to moisture. Water soluble.

Reactivity Profile

Promethazine hydrochloride is sensitive to light. In aqueous solution, Promethazine hydrochloride is degraded by heat and light (more rapidly in air or oxygen). Incompatible with alkalis and alkaline solutions such as those of aminophylline, soluble barbiturates and phenytoin sodium. Iron(III) and copper(III) accelerate the degradation .

Fire Hazard

Flash point data for Promethazine hydrochloride are not available; however, Promethazine hydrochloride is probably combustible.

Clinical Use

Antihistamine

Safety Profile

Poison by ingestion, subcutaneous, intraperitoneal, and intravenous routes. Human systemic effects by ingestion: excitement, sleep, convulsions, rigdity. Experimental teratogenic effects. Other experimental reproductive effects. When heated to decomposition it emits very toxic fumes of HCl, SOx, and NOx. Used as an antihstamine.

Veterinary Drugs and Treatments

Promethazine may be useful in dogs and cats as an antiemetic. Because of its antihistamine actions, it has been tried for treating pruritus in atopic dogs, but its efficacy has been poor.

Drug interactions

Potentially hazardous interactions with other drugs
Analgesics: possibly increased sedative effects.

Metabolism

Extensively hepatically metabolised, mainly to promethazine sulfoxide, and also to N-desmethylpromethazine.
It is excreted slowly via the urine and bile, mainly as metabolites.

Dosage forms

12.5 mg PO q.i.d.; 25 mg PO at bedtime. May contain saccharin.