 |
|
|
Pholcodine
|
|
| Systematic (IUPAC) name | |
| 7,8-didehydro- 4,5α-epoxy- 17-methyl- 3- [2- (morpholin- 4- yl) ethoxy] morphinan- 6α-ol | |
| Identifiers | |
| CAS number | 509-67-1 |
| ATC code | R05DA08 |
| PubChem | ? |
| DrugBank | ? |
| Chemical data | |
| Formula | C23H30N2O4 |
| Mol. mass | 398.55 g/mol |
| Pharmacokinetic data | |
| Bioavailability | Maximum plasma conc. attained 4-8 hours after oral dose. |
| Protein binding | 23.5% |
| Metabolism | Hepatic |
| Half life | 32-43 hours; volume of distribution is 36-49L/kg. |
| Excretion | Renal |
| Therapeutic considerations | |
| Pregnancy cat. |
A(AU) |
| Legal status |
Class B(UK) Schedule I(US) OTC (UK) |
| Dependence Liability | Low |
| Routes | Oral
|
Pholcodine is a drug which is an opioid cough suppressant (antitussive). It helps suppress unproductive coughs and also acts as an antifungal agent.[citation needed] It also has a mild sedative effect, but has little or no analgesic effects. It is also known as morpholinylethylmorphine.
Pholcodine is found in certain cough lozenges. [1] However, in the UK, the preparation is almost exclusively an oral solution, typically 5 mg / 5 ml. Adult dosage is 5-10ml up to 3-4 times daily[1]. Pholcodine now largely replaces the previously more common codeine linctus, as it has a much lower potential for dependence.
Pholcodine is a Schedule I drug in the US.
Contents |
Mechanism of action
Pholcodine is readily absorbed from the gastrointestinal tract and freely crosses the blood-brain barrier. It acts primarily on the central nervous system (CNS), causing depression of the cough reflex, partly by a direct effect on the cough centre in the medulla. It is metabolized in the liver and its action may be prolonged in individuals with hepatic insufficiency (i.e. liver problems). Its use is therefore contraindicated in patients with liver disease, while care is advised in patients with hepatic impairement.
Side effects
Side effects are rare and may include dizziness and gastrointestinal disturbances such as nausea or vomiting.
Adverse effects such as constipation, drowsiness, excitation, ataxia and respiratory depression have been reported occasionally or after large doses.
A Norwegian cough-syrup containing pholcodine "Tuxi" has been withdrawn from the market because it caused increased levels of IgE-antibodies, regardless of an actual allergy to the drug. This is believed to increase the risk of anaphylaxis to neuromuscular blocking agents used during anaesthesia.
See also
References
- ^ BNF (2007). British National Formulary 54. BMJ Publishing Group Ltd., RPS Publishing, London. Page 175.
External links
- Australian Therapeutic Goods Admission document on Pholcodine (Rich Text Format)
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
||||||||||||||||
This entry is from Wikipedia, the leading user-contributed encyclopedia. It may not have been reviewed by professional editors (see full disclaimer)
