The drug ketamine, which is widely used as a tranquilizer for horses, has shown promise for use in treatment-resistant depression.
Le-Ban Wan, MD, PhD, a psychiatrist in private practice in New York, and colleagues examined data from 205 IV infusions of ketamine (0.5 mg/kg over 40 minutes) in 97 participants with major depressive disorder in clinical trials conducted between 2006 and 2012.
The overall antidepressant response rate, defined as a ≥ 50% improvement in Montgomery-Asberg Depression Rating Scale score, was 67%, the researchers reported in the Journal of Clinical Psychiatry. The overall attrition rate was only 3.1%.
Researchers found that ketamine was generally well tolerated, with drowsiness, dizziness, poor coordination and blurred vision as the most common adverse events reported within the first four hours after infusion. However, the drug resulted in small but significant increases in psychotomimetic and dissociative symptoms (all P<.05). But there were no cases of persistent psychotomimetic effects.
“Further research investigating the safety of ketamine in severe and refractory depression is warranted,” the researchers concluded.
Ketamine is also being looked at for other psychiatric disorders. A study published in July found that the drug was effective in relieving symptoms associated with post-traumatic stress disorder.
Ketamine has demonstrated rapid antidepressant effects in patients with treatment-resistant depression (TRD); however, the safety and tolerability of ketamine in this population have not been fully described. Herein we report the largest study to date of the safety, tolerability, and acceptability of ketamine in TRD.
Data from 205 IV ketamine infusions (0.5 mg/kg over 40 minutes) in 97 participants with DSM-IV–defined major depressive disorder were pooled from three clinical trials conducted between 2006 and 2012 at two academic medical centers. Safety and tolerability measures included attrition, adverse events, hemodynamic changes, and assessments of psychosis and dissociation.