You'll see some patients take dextromethorphan for pain.
It's NOT very effective by itself...but it increases and prolongs the analgesic effect of opioids such asmorphine.
Dextromethorphan blocks NMDA (N-methyl-D-aspartate) receptors that increase sensitivity to pain.
Researchers are combining equal doses of dextromethorphan and morphine...for example, 30 mg of DM and 30 mg ofmorphine.
This combination seems to be as effective as doubling the morphine dose. It might also be less constipatingbecause it allows patients to use less morphine.
Some physicians prescribe dextromethorphan with morphine for hospice patients. In the future, you may see anew product that contains both called MorphiDex.
Advise patients taking both dextromethorphan and morphine that the combination might cause more sedation ordizziness.
Drugs 1998;55:1. Clin Pharmacol Ther 1998;63(2); OI-B-3, PI-10, PI-12. Neurology 1997;48:1212. Anesth Analg 1998;86:594.