c) multicomponent cold medicine containing phenylpropanolamine
A capsule containing paracetamol 150 mg, salicylamide 150 mg, chlorpheniramine maleate 2 mg, phenylephrine 5 mg, caffeine 30 mg, and phenylpropanolamine 25 mg.
For older traditional combination products such as that above, you need to work out the classification of each component, the classification of the product will be that of the most stringently classified component.
Classification of the following:
Paracetamol: NP (unless in IV form)
Salicylamide: NP. Salicylamide is a salicylic acid derivative (related to aspirin which is acetylsalicylic acid) but is not hydrolysed to salicylate; it is almost completely metabolised to inactive metabolites during absorption and on first pass through the liver (Martindale)
Chlorpheniramine maleate: P2 antihistamine (you can find this through the Drug Office's classification guide)
Phenylephrine: NP (unless in IV form)
- Phenylephrine is a sympathomimetic drug used to help reduce the symptoms of nasal decongestion. Pseudoephedrine used to be commonly used in cold preparations but has been widely replaced by phenylephrine due to abuse (illegal synthesis of methamphetamine) (AHFS Drug information).
- Phenylpropanolamine class entry: Alpha-Methylphenethylamine; beta-methylphenethylamine; alpha-ethylphenethylamine; beta-ethylphenethylamine; their optical isomers; etc. This entry can be found in the S10/P1 and S1 lists
- In the S3 list:
- "Alpha-Methylphenethylamine; beta-methylphenethylamine; alpha- ethylphene-thylamine; beta-ethylphenethylamine; their optical isomers; etc... except ... phenylpropanolamine."
- Similar to phenylephrine, it is a sympathomimetic drug used as a nasal decongestant in cold preparations, and was used to replace pseudoephedrine. In the US phenylpropanolamine was used as an appetite suppressant (150 mg a day) (Martindale) which was found to increase the risk of haemmorrhagic stroke leading to its withdrawal from the US market even from cold medicines. Overall phenylpropanolamine is safe if used at appropriate doses.