PHOLCOLIN

Chlorphenamine is a potent antihistamine (H₁-antagonist). Antihistamines diminish or abolish the actions of histamine in the body by competitive reversible blockade of histamine H₁-receptor sites on tissues. Chlorphenamine also has anticholinergic activity.

Phenylpropanolamine is a sympathomimetic agent which is used as a decongestant and appetite suppressant. It was commonly used in prescription and over-the-counter cough and cold preparations. Although originally thought to act as a direct agonist of adrenergic receptors, phenylpropanolamine was subsequently found to show only weak or negligible affinity for these receptors, and has been instead characterized as an indirect sympathomimetic which acts by inducing norepinephrine release and thereby activating adrenergic receptors.

Pholcodine is an opioid that has been widely used for the treatment of non-productive cough in children and adults. Pholcodine is a cough suppressant with mild sedative but little analgesic activity. Additionally pholcodine is a marker for sensitization to neuromuscular blocking agents (NMBA) and is intended for use as a diagnostic tool in NMBA-induced anaphylaxis.