OPEN Foundation

C. Andrade

Ketamine for Depression, 4: In What Dose, at What Rate, by What Route, for How Long, and at What Frequency?

Abstract

BACKGROUND:
Ketamine, administered in subanesthetic doses, is an effective off-label treatment for severe and even treatment-refractory depression; however, despite dozens of studies across nearly 2 decades of research, there is no definitive guidance on matters related to core practice issues.
METHODS:
This article presents a qualitative review and summary about what is known about ketamine dosing, rate of administration, route of administration, duration of treatment, and frequency of sessions.
RESULTS:
Ketamine is most commonly administered in the dose of 0.5 mg/kg, but some patients may respond to doses as low as 0.1 mg/kg, and others may require up to 0.75 mg/kg. The ketamine dose is conventionally administered across 40 minutes; however, safety and efficacy have been demonstrated in sessions ranging between 2 and 100 minutes in duration. Bolus administration is safe and effective when the drug is administered intramuscularly or subcutaneously. Whereas the intravenous route is the most commonly employed, safety and efficacy have been described with other routes of administration, as well; these include oral, sublingual, transmucosal, intranasal, intramuscular, and subcutaneous routes. Patients may receive a single session of treatment or a course of treatment during the acute phase, and treatment may rarely be continued for weeks to years to extend and maintain treatment gains in refractory cases. When so extended, the ideal frequency is perhaps best individualized wherein ketamine is dosed a little before the effect of the previous session is expected to wear off.
CONCLUSIONS:
There is likely to be a complex interaction between ketamine dose, session duration, route of administration, frequency of administration, and related practice. Until definitive studies comparing different doses, rates of administration, routes of administration, and other considerations are conducted, firm recommendations are not possible. From the point of view of clinical practicability, subcutaneous, intranasal, and oral ketamine warrant further study. If domiciliary treatment is considered, the risk of abuse must be kept in mind.
Andrade, C. (2017). Ketamine for Depression, 4: In What Dose, at What Rate, by What Route, for How Long, and at What Frequency?. The Journal of clinical psychiatry78(7), e852-e857. 10.4088/JCP.17f11738
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Ketamine for Depression, 3: Does Chirality Matter?

Abstract

Ketamine is a racemic mixture of the enantiomers R-ketamine and S-ketamine (esketamine). S-ketamine has greater analgesic and anesthetic effects than R-ketamine and is less likely to cause psychotomimetic and other adverse effects. There is therefore an emerging interest favoring the use of S-ketamine over racemic ketamine when the drug is used for analgesia or anesthesia. This article examines preclinical and clinical literature on the antidepressant properties of S-ketamine. Animal data suggest potential advantages for R-ketamine over S-ketamine. Case reports, case series, and some small randomized controlled trials suggest that single or repeated intravenous infusions (0.2-0.4 mg/kg) or intranasal administrations (28-84 mg) of S-ketamine have antidepressant action in patients with medication-refractory depression and that the observed benefits are similar in magnitude to the antidepressant benefits reported with racemic ketamine. However, there are no direct comparisons between S-ketamine and either R-ketamine or racemic ketamine in depressed patients; therefore, it is not possible to make an informed choice when considering the enantiomers and the racemate for the indication of depression.
Andrade, C. (2017). Ketamine for Depression, 3: Does Chirality Matter?. The Journal of clinical psychiatry78(6), e674-e677. 0.4088/JCP.17f11681
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Ketamine for Depression, 1: Clinical Summary of Issues Related to Efficacy, Adverse Effects, and Mechanism of Action

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.
Andrade, C. (2017). Ketamine for Depression, 1: Clinical Summary of Issues Related to Efficacy, Adverse Effects, and Mechanism of Action. The Journal of clinical psychiatry78(4), e415. 10.4088/JCP.17f11567
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Intranasal drug delivery in neuropsychiatry: focus on intranasal ketamine for refractory depression.

Abstract

Intranasal drug delivery (INDD) systems offer a route to the brain that bypasses problems related to gastrointestinal absorption, first-pass metabolism, and the blood-brain barrier; onset of therapeutic action is rapid, and the inconvenience and discomfort of parenteral administration are avoided. INDD has found several applications in neuropsychiatry, such as to treat migraine, acute and chronic pain, Parkinson disease, disorders of cognition, autism, schizophrenia, social phobia, and depression. INDD has also been used to test experimental drugs, such as peptides, for neuropsychiatric indications; these drugs cannot easily be administered by other routes. This article examines the advantages and applications of INDD in neuropsychiatry; provides examples of test, experimental, and approved INDD treatments; and focuses especially on the potential of intranasal ketamine for the acute and maintenance therapy of refractory depression.

Andrade, C. (2015). Intranasal drug delivery in neuropsychiatry: focus on intranasal ketamine for refractory depression. The Journal of clinical psychiatry, 76(5), e628-31. https://dx.doi.org/10.4088/JCP.15f10026

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30 April - Q&A with Rick Strassman

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