The Sound of Evolution
Dextromethorphan
Mechanism of action:
Dextromethorphan is a centrally acting antitussive agent and the (S)-enantiomer of methorphan, with dextrorotatory optical activity. It is thought to bind to and activate σ₁ receptors within the cough reflex pathway of the medulla. Activation of σ₁ receptors can modulate multiple ion channels, including Ca²⁺ and K⁺ channels, as well as neurotransmitter release, thereby suppressing the excitability of cough center neurons and reducing the initiation and transmission of the cough reflex.
Reference(s):
1. Brooks BR et al. (2004). Treatment of pseudobulbar affect in ALS with dextromethorphan/quinidine: a randomized trial. Neurology.
2. Olney JW et al. (1989). Pathological changes induced in cerebrocortical neurons by phencyclidine and related drugs. Science.
3. Hargreaves RJ et al. (1994). Neuroprotective NMDA antagonists: the controversy over their potential for adverse effects on cortical neuronal morphology. Acta Neurochir Suppl.