Racemethorphan

Racemethorphan is a cough suppressant and the racemic form of dextromethorphan. It is used in over-the-counter cough and cold preparations. Racemethorphan is a sigma-1 receptor agonist and an NMDA receptor antagonist. It is structurally similar to other morphinans such as codeine and morphine.

Pharmacology

Racemethorphan acts primarily as a sigma-1 receptor agonist and an NMDA receptor antagonist. The sigma-1 receptor is a chaperone protein at the endoplasmic reticulum (ER), and it modulates the activity of various ion channels and receptors. Meanwhile, the NMDA receptor is a glutamate receptor and ion channel protein found in nerve cells. By blocking this receptor, racemethorphan can prevent the cough reflex.

Medical Uses

Racemethorphan is used as a cough suppressant in many over-the-counter cold and flu medications. It is often combined with other ingredients such as antihistamines, decongestants, and pain relievers.

Side Effects

Common side effects of racemethorphan include drowsiness, dizziness, nausea, and vomiting. In rare cases, it can cause serious side effects such as hallucinations, severe dizziness, and trouble breathing.

See Also

• Dextromethorphan
• Sigma-1 receptor
• NMDA receptor