Metoclopramide-induced supersensitivity psychosis.
OBJECTIVE
To report 2 cases of metoclopramide-induced supersensitivity psychosis.


METHODS
A 74-year-old Taiwanese man was treated with metoclopramide 5 mg 4 times daily for 6 months. A second patient, a 65-year-old Taiwanese man, was treated with metoclopramide 5 mg 4 times daily for 3 months. After discontinuation of metoclopramide, both patients developed hallucinatory experiences and delusions.


CONCLUSIONS
This is the first report of metoclopramide-induced supersensitivity psychosis. Chronic administration of a dopamine antagonist (e.g., metoclopramide) might induce dopamine receptor supersensitivity. It is hypothesized that exacerbation or occurrence of psychotic symptoms following neuroleptic withdrawal results from mesolimbic dopamine supersensitivity.


CONCLUSIONS
The complications of long-term metoclopramide therapy should be seriously considered when the treatment regimens are being planned. Clinicians should attempt to treat patients with the lowest effective dosage of medication for the briefest therapeutic period to minimize the risks of adverse reactions.
Lu
Mong-Liang
ML
Department of Psychiatry, Taipei Medical University--Wan Fang Hospital and Taipei Medical University, Taipei, Taiwan.
Pan
Jan-Jhy
JJ
Teng
Hui-Wen
HW
Su
Kuan-Pin
KP
Shen
Winston W
WW
D000368:Aged; D000932:Antiemetics / Q000009:adverse effects* / Q000627:therapeutic use; D014150:Antipsychotic Agents / Q000627:therapeutic use; D003924:Diabetes Mellitus, Type 2 / Q000150:complications; D004342:Drug Hypersensitivity / Q000523:psychology*; D006212:Hallucinations / Q000523:psychology; D006801:Humans; D008297:Male; D008787:Metoclopramide / Q000009:adverse effects* / Q000627:therapeutic use; D011605:Psychoses, Substance-Induced / Q000188:drug therapy / Q000523:psychology*; D018967:Risperidone / Q000627:therapeutic use; D020521:Stroke / Q000150:complications; D013375:Substance Withdrawal Syndrome / Q000523:psychology; D014839:Vomiting / Q000188:drug therapy
D000932:Antiemetics; D014150:Antipsychotic Agents; D008787:Metoclopramide; D018967:Risperidone