A large Cochrane review of 67 randomized trials (>2,300 patients) found no clear evidence that ketamine or other NMDA-receptor antagonists reduce chronic non-cancer pain. Evidence quality was rated low to very low, so current data do not reliably support ketamine as an effective pain treatment.
Dextromethorphan (DXM), found in cough meds, acts like mild ketamine. Combined with bupropion to slow its breakdown, it works quickly for depression. This combo was FDA-approved in 2022 as Auvelity.
