1 Department of Psychopharmacology, National Institute of Mental Health and Neurosciences, Bangalore, India. candrade@psychiatrist.com.
Chittaranjan Andrade, MD
- Ketamine is an anesthetic drug. It is used in subanesthetic doses to treat pain, to effect sedation, or to ameliorate depression in various contexts.
- Ketamine as an antidepressant is most commonly administered as an intravenous infusion, across 40 minutes, in the dose of 0.5 mg/kg. It can also be administered by other routes.
- Antidepressant benefits with ketamine are usually dramatic; patients may achieve response and even remission of depression within a day, even when the depression was previously medication refractory. The benefits are usually lost in 3-12 days. Maintenance treatment with ketamine, scheduled once in 2-4 days, can maintain the treatment gains.
- Dissociative and psychotomimetic adverse effects are common but very seldom problematic.
Abstract
Ketamine is an anesthetic drug that is also used for off-label indications such as the mediation of analgesia and sedation in various settings. It is additionally recognized as an agent with antidepressant potential. For depression, it is most commonly administered as a slow intravenous infusion in subanesthetic doses (usually 0.5 mg/kg). As an antidepressant, is strikingly different from conventional antidepressant drugs in that it brings about rapid and marked attenuation of depressive symptoms even in patients with refractory depression. The benefits are observed within hours of administration, peak after about a day, and are lost 3-12 days later. Patients who do not benefit after the initial dose may benefit with serial dosing or at higher doses. Benefits can be maintained for weeks to months by the continuation of ketamine sessions at 2- to 4-day intervals. Adverse effects include dissociative and psychotomimetic changes that are almost always mild and transient, if present; transient elevation of heart rate and blood pressure often occur. These changes are usually well tolerated and are very seldom responsible for treatment discontinuation. Whereas ketamine is an N-methyl-d-aspartate receptor antagonist, and whereas much is known about its different biological effects, its actions that mediate the antidepressant response are presently not known for certain. Although big data on ketamine are presently unavailable, the drug holds promise in the treatment of depression, especially refractory depression.
J Clin Psychiatry 2017;78(4):e415-e419
https://doi.org/10.4088/JCP.17f11567
