WikiPortallus: Promethazine.html

Promethazine is a first-generation H₁ receptor antagonist antihistamine and antiemetic medication. It is a prescription drug in the United States, but is available over the counter in the United Kingdom, Switzerland, and many other countries (brand names Phenergan, Promethegan, Romergan, Fargan, Farganesse, Prothiazine, Avomine, Atosil, Receptozine).¹

Promethazine also has strong anticholinergic and sedative effects. Previously it was used as an antipsychotic²., although it is generally not administered for this purpose now; promethazine has only approximately 1/10 of the antipsychotic strength of chlorpromazine.

Chemically, promethazine hydrochloride (HCl) appears as a white to faint yellow crystaline powder which is practically odorless. Slow oxidation may occur upon prolonged exposure to air causing blue discoloration. Promethazine as the hydrochloride salt is freely soluble in water and somewhat soluble in alcohol.³

Indications

Contraindications

Mechanism of action

Side effects

It is recommended that Promethazine only be given through an existing intravenous set in a large vein and diluted to concentration no greater than 25mg per ml, not to exceed a rate of administration of 25mg a min. Serious complications including those listed above have resulted from improper parenteral administration, including those requiring surgical intervention and amputation.¹⁰

Laboratory examinations

All patients should have their blood pressure measured frequently. During long-term therapy, blood cell counts, liver function studies, EKG, and EEG are recommended. The intervals should be determined according to the risk profile of the patient. In high doses Promethazine can create auditory and visual hallucinations causing panic and intense fear.

Recreational use

Promethazine is sometimes used as a recreational drug in conjunction with codeine in prescription cough syrup. The syrup by itself contains 7% alcohol. The traditional mixture of Sprite and cough syrup with codeine, which is known as "purple drank","Sizzurp", or "lean" is popularized in the rap world, especially in the Houston area.¹¹ It is also sometimes used to counteract nausea caused by illicit opioid use.

Politics

The U.S. Supreme Court has accepted a case involving Promethazine that may influence product liability. A musician suffering from a migraine was administered Wyeth's Phenergan via IV push. The drug entered her arterial flow resulting in gangrene and subsequent amputation of her right arm below the elbow. A state jury awarded her $6 million in punitive damages. The case has been appealed to the Supreme Court on grounds of federal pre-emption.¹²

References

^ RxList: Promethazine
^ [1]
^ http://www.rxlist.com/cgi/generic/phenergan.htm RxList: Promethazine Description
^ ^a ^b ^c ^d ^e RxList Indications for Promethazine
^ British National Formulary (March 2003). "4.6 Drugs used in nausea and Vertigo - Vomiting of pregnancy". "BNF" (45 ed.).
^ "Letter from Wyeth Pharmaceuticals to practitioners regarding use of Phenergan in under twos" (PDF). FDA.
^ ^a ^b ^c ^d ^e ^f ^g RxList Contraindications
^ David J McCann and Brett Roth, Toxicity, Antihistamine, eMedicine Toxicology, updated June 21, 2007
^ Cordingley Neurology
^ Baxter: Promethazine HCl Injection, USP Information
^ Peters RJ, Kelder SH, Markham CM, Yacoubian GS, Peters LA, Ellis A (2003). "Beliefs and social norms about codeine and promethazine hydrochloride cough syrup (CPHCS) onset and perceived addiction among urban Houstonian adolescents: an addiction trend in the city of lean". J Drug Educ 33 (4): 415–25. doi:10.2190/NXJ6-U60J-XTY0-09MP. PMID 15237866.
^ Liptak, Adam (2008-09-18). "Drug Label, Maimed Patient and Crucial Test for Justices", The New York Times. Retrieved on 31 October 2008.