title: Diltiazem as augmentation therapy in patients with treatment-resistant bipolar disorder: a retrospective study.
abstract: OBJECTIVE
  To examine the efficacy of a slow-release formulation of diltiazem as adjunctive therapy in patients with treatment-resistant bipolar disorder.
  
  
  METHODS
  Retrospective study.
  
  
  METHODS
  Eight female patients with treatment-resistant bipolar disorder.
  
  
  METHODS
  Patients were administered diltiazem and monitored for a 6-month period before starting diltiazem and a 6-month period after starting the drug.
  
  
  METHODS
  All patients were seen at least monthly and usually every 2 weeks. The frequency and severity of both depressive and manic episodes were examined during the 6-month period after starting diltiazem, and compared with those during the 6-month period before diltiazem treatment.
  
  
  RESULTS
  There was a statistically significant decrease in the frequency and severity of both manic and depressive episodes in these patients after they started treatment with diltiazem, compared with the period before they started treatment with diltiazem (p < 0.001). There was no evidence of side effects requiring patient withdrawal or of drug interactions.
  
  
  CONCLUSIONS
  The results support previous suggestions that calcium-channel antagonists may be an effective adjunctive treatment in the management of bipolar disorder. Further controlled clinical studies are needed to confirm this small, open-label, retrospective study.
authors.affiliation: Department of Psychiatry, University of Alberta, Edmonton.
authors.forename: P H
authors.initials: PH
authors.lastname: Silverstone
authors.forename: L
authors.initials: L
authors.lastname: Birkett
mesh_terms: D000928:Antidepressive Agents / Q000627:therapeutic use*; D001714:Bipolar Disorder / Q000175:diagnosis / Q000188:drug therapy*; D002121:Calcium Channel Blockers / Q000627:therapeutic use*; D004110:Diltiazem / Q000627:therapeutic use*; D004351:Drug Resistance; D004359:Drug Therapy, Combination; D005260:Female; D006801:Humans; D008297:Male; D012189:Retrospective Studies; D012720:Severity of Illness Index
chemical_list: D000928:Antidepressive Agents; D002121:Calcium Channel Blockers; D004110:Diltiazem