Phenylpropanolamine
From Wikipedia, the free encyclopedia
 |
This article is in need of attention from an expert on the subject. WikiProject Pharmacology or the Pharmacology Portal may be able to help recruit one. (November 2008) |
 |
|
|
Phenylpropanolamine
|
|
| Systematic (IUPAC) name | |
| (1R,2S)-2-amino-1-phenyl-propan-1-ol | |
| Identifiers | |
| CAS number | |
| ATC code | R01 |
| PubChem | |
| DrugBank | |
| ChemSpider | |
| Chemical data | |
| Formula | C9H13NO |
| Mol. mass | 151.206 g/mol |
| Pharmacokinetic data | |
| Bioavailability | ? |
| Metabolism | ? |
| Half life | 2.1 to 3.4 hours. |
| Excretion | ? |
| Therapeutic considerations | |
| Pregnancy cat. |
? |
| Legal status | |
| Routes | Oral |
Phenylpropanolamine (PPA) is a drug ingredient of the phenethylamine family used as a decongestant[1] in prescription and nonprescription (over the counter) cough and cold, and sinus remedies, and some combination allergy medications. It is also present in an appetite suppressant.[2] In veterinary medicine, it is used to control urinary incontinence in dogs and is sold under brand names Propalin and Proin.
In the United States, PPA is no longer sold without a prescription due to a theorized increased risk of stroke in younger women. In Europe, it is available by prescription and over-the-counter. In Canada, this drug ingredient was withdrawn from the market on May 31, 2001.[2]
Contents |
[edit] Chemistry
There are four optical isomers of phenylpropanolamine: d- and l-norephedrine, and d- and l-norpseudoephedrine. D-norpseudoephedrine is also known as cathine, and occurs naturally in the stimulant plant Catha edulis (khat). This isomer is commonly used in European medications described as "phenylpropanolamine", whereas in the United States a racemic mixture of d,l-norephedrine is usual.[citation needed]
Just as ephedrine is chemically reduced into methamphetamine, phenylpropanolamine can be chemically reduced into amphetamine. Molecularly, phenylpropanolamine is to ephedrine, just as amphetamine is to methamphetamine, and as cathinone is to methcathinone. The former all are primary amines, the latter are secondary amines with a methyl group attached to the nitrogen.[citation needed]
Phenylpropanolamine can be made from cathinone by reduction of the ketone.[citation needed]
[edit] Side effects
A scientific study[3] found an increased risk of hemorrhagic stroke in women who used phenylpropanolamine, although it is not clear which isomer is to blame. A study at the Yale University School of Medicine in 1999 had produced similar results.[1] Reports of cases of hemorrhagic strokes in PPA users had been circulating since the 1970s.
A report from the Dept. of Psychiatry, F. Edward Hebert School of Medicine, Bethesda, Maryland in Pharmacopsychiatry[4] states:
We have reviewed 37 cases (published in North America and Europe since 1960) that received diagnoses of acute mania, paranoid schizophrenia, and organic psychosis and that were attributed to PPA product ingestion. Of the 27 North American case reports, more reactions followed the ingestion of combination products than preparations containing PPA alone; more occurred after ingestion of over-the-counter products than those obtained by prescription or on-the-street; and more of the cases followed ingestion of recommended doses than overdoses.
Failure to recognize PPA as an etiological agent in the onset of symptoms usually led to a diagnosis of schizophrenia or mania, lengthy hospitalization, and treatment with substantial doses of neuroleptics or lithium.
[edit] Legal status
In Europe, PPA is still available in prescription decongestants such as Rinexin [5] as well as over-the-counter medication such as Wick DayMed.
In the United Kingdom, PPA is available in many 'all in one' cough/cold medications which usually also feature paracetamol (or another painkiller) and caffeine. It can also be purchased on its own. It is classed as GSL (general sale license) and is completely derestricted, therefore saleable by any shop.
In the United States, the Food and Drug Administration (FDA) issued a public health advisory[6] against the use of the drug in November 2000. In this advisory, the FDA requested that all drug companies discontinue marketing products containing phenylpropanolamine. The agency estimates that PPA caused between 200 and 500 strokes per year among 18-to-49-year-old users. In 2005 the FDA removed phenylpropanolamine from over-the-counter sale.[7] Because of its potential use in amphetamine manufacture, it is controlled by the Combat Methamphetamine Epidemic Act of 2005. It is still available for use in dogs.
Internationally, an item on the agenda of the 2000 Commission on Narcotic Drugs session called for including phenylpropanolamine in Table I of United Nations Convention Against Illicit Traffic in Narcotic Drugs and Psychotropic Substances[8]
It is available in India in the form of a combination tablet with Cetirizine as Alerid-D manufactured by Cipla.
[edit] See also
- Chlorphenamine
- phenethylamines
- Cathine
- ephedrine
- pseudoephedrine
- cathinone
- methcathinone
- amphetamine
- methamphetamine
- phenmetrazine
- 4-methylaminorex
[edit] References
- ^ Flavahan NA (April 2005). "Phenylpropanolamine constricts mouse and human blood vessels by preferentially activating alpha2-adrenoceptors". J. Pharmacol. Exp. Ther. 313 (1): 432–9. doi:. PMID 15608085. http://jpet.aspetjournals.org/cgi/pmidlookup?view=long&pmid=15608085.
- ^ a b Health Canada withdraws drug products containing phenylpropanolamine (PPA) from the market
- ^ Kernan WN, Viscoli CM, Brass LM, et al. (December 2000). "Phenylpropanolamine and the risk of hemorrhagic stroke". N. Engl. J. Med. 343 (25): 1826–32. doi:. PMID 11117973. http://content.nejm.org/cgi/content/abstract/343/25/1826.
- ^ Lake CR, Masson EB, Quirk RS (July 1988). "Psychiatric side effects attributed to phenylpropanolamine". Pharmacopsychiatry 21 (4): 171–81. doi:. PMID 3060884.
- ^ Rinexin in Farmaceutiska Specialiteter i Sverige - the Swedish official drug catalog.(in Swedish)
- ^ Food and Drug Administration Public Health Advisory, "Safety of Phenylpropanolamine"
- ^ FDA moves PPA from OTC
- ^ Implementation of the international drug control treaties: changes in the scope of control of substances, Commission on Narcotic Drugs, Forty-third session, Vienna, 6-15 March 2000.
[edit] External links
- Phenylpropanolamine Information Page at www.FDA.gov
- A Dose of Denial: How drug makers sought to keep popular cold and diet remedies on store shelves after their own study linked them to strokes. By Kevin Sack and Alicia Mundy.Los Angeles Times, March 28, 2004.
- Doubt Is Their Product by David Michaels, Scientific American, June 2005
- Phenylpropanolamine by Richard Clapp, a case study at DefendingScience.org
- Widely Circulated Email About Phenylpropanolamine Description of widely circulated email using out-of-date information about Phenylpropanolamine.
- Treatment of urethral sphincter mechanism incompetence in 11 bitches with a sustained-release formulation of phenylpropanolamine hydrochloride Use of Phenylpropanolamine in dogs.
|
|||||||||||||||||||
