Opioids a better treatment for acute than tardive akathisia: possible role for the endogenous opiate system in neuroleptic-induced akathisia.

Patients who are on neuroleptics with acute akathisia improve more with opioid therapy than patients who are off neuroleptics with tardive akathisia. Since tardive akathisia usually occurs after long term neuroleptic exposure, we propose that this difference in therapeutic response is due to permanent changes in receptor sensitivity that arise from such prolonged exposure. We have previously described a patient with severe acute akathisia whose motor restlessness was totally suppressed by opioid therapy. This improvement was rapidly reversed by the opiate receptor blocker naloxone. This suggests that the endogenous opiate system is involved in the pathogenesis of neuroleptic-induced akathisia.