Repeated intravenous ketamine therapy in a patient with treatment-resistant major depression.
BACKGROUND
The intravenous administration of ketamine, an N-methyl-D-aspartate receptor antagonist, results in a great improvement of depression symptoms, but it is not clear for how long. This single-case trial was conducted to explore the duration of improvement and the effects of a second administration on the clinical outcome.


METHODS
In an open label trial, a 55-year-old male patient with treatment-resistant major depression and a co-occurring alcohol and benzodiazepine dependence received two intravenous infusions of 0.5 mg/kg ketamine over the course of 6 weeks. Depression severity was assessed by means of a weekly clinical interview, the 21-item Hamilton Depression Rating Scale (HDRS), and the 21-item Beck Depression Inventory (BDI).


RESULTS
The first ketamine infusion lead to a pronounced improvement of symptoms, peaking on the second day post infusion (HDRS -56.6%, BDI -65.4%). Positive effects started fading by day 7, reaching baseline by day 35. The second infusion was less efficacious: HDRS and BDI were reduced by 43 and 35%, respectively, and returned to baseline by day 7.


CONCLUSIONS
In this patient with a co-occurring substance use disorder, repeated administrations of ketamine produced positive results. Since the second application has been less efficacious, doses and schedule of administrations need to be further investigated.
Liebrenz
Michael
M
Psychiatric University Hospital, Research Group on Substance Use Disorders, Zurich, Switzerland. Michael.Liebrenz@puk.zh.ch
Stohler
Rudolf
R
Borgeat
Alain
A
D000778:Anesthetics, Dissociative / Q000008:administration & dosage*; D000928:Antidepressive Agents / Q000009:adverse effects / Q000627:therapeutic use; D003865:Major Depressive Disorder / Q000175:diagnosis / Q000188:drug therapy* / Q000523:psychology; D004334:Drug Administration Schedule; D004351:Drug Resistance; D004359:Drug Therapy, Combination; D018691:Excitatory Amino Acid Antagonists / Q000008:administration & dosage*; D006801:Humans; D007262:Infusions, Intravenous; D007649:Ketamine / Q000008:administration & dosage*; D008297:Male; D008875:Middle Aged; D010555:Personality Inventory / Q000706:statistics & numerical data; D011594:Psychometrics; D012008:Recurrence; D019233:Retreatment
D000778:Anesthetics, Dissociative; D000928:Antidepressive Agents; D018691:Excitatory Amino Acid Antagonists; D007649:Ketamine