Safety and efficacy of maintenance ketamine treatment in patients with treatment-refractory generalised anxiety and social anxiety disorders

Summary & key facts

Researchers gave weekly low-dose ketamine injections for three months to 20 people whose anxiety had not gotten better with other treatments. Anxiety scores fell a lot one hour after doses, and 18 of the 20 people said their work or social life improved during the treatment. Side effects like nausea, dizziness and blurred vision were common and blood pressure rose by about 10 mm Hg after dosing. The study was small, had no comparison group, and only included people who had already responded to ketamine before, so the results need confirmation in larger, controlled studies.

Key facts:

• The study treated 20 people with treatment-resistant generalized anxiety disorder and/or social anxiety disorder for three months with one or two weekly ketamine injections of about 1 mg per kg of body weight.
• About one hour after dosing, anxiety ratings fell by roughly half on two standard anxiety measures.
• Eighteen of the 20 people reported better social or work functioning during the maintenance treatment.
• Dissociative feelings after dosing (a sense of disconnection or strange sensations) were measured and became smaller over time, falling from a mean score of about 20 at week 1 to about 9 by week 14.
• Average blood pressure rose by about 10 mm Hg at 30 minutes after dosing compared with before dosing.
• The most common side effects were nausea, dizziness and blurred vision.
• The trial was uncontrolled and open-label, which means there was no comparison group and both patients and doctors knew ketamine was being given. The participants had already shown a response to ketamine in an earlier study, so the results may not apply to everyone with these anxiety disorders.

Abstract

Objective: In this maintenance treatment study, we sought to evaluate the effect on anxiety ratings, safety and tolerability of 3 months of weekly ketamine in 20 patients with treatment-refractory DSM IV generalised anxiety disorder (GAD) and/or social anxiety disorder (SAD), and subsequent assessment of remission post-treatment. Methods: This was an uncontrolled open-label study in 20 patients who had been responders in an ascending dose ketamine study. The study was undertaken in a university clinic. Patients received one or two weekly ketamine doses of 1 mg/kg injected subcutaneously for 3 months. Data were collected from December 2015–June 2017. Results: There were 10 women (50%) and 10 men (50%); 15 patients (75%) met criteria for GAD and 18 (90%) for SAD. One hour after dosing, Fear Questionnaire ratings decreased by ~50%, as did Hamilton Anxiety ratings. Clinician Administered Dissociative States Scale mean scores declined over time, from 20 points at week 1 to 8.8 points at week 14. Compared with pre-dose values, mean systolic and diastolic blood pressure increased by ~10 mm Hg at 30 min. The most common adverse events were nausea, dizziness and blurred vision. Of the 20 patients, 18 reported improved social functioning and/or work functioning during maintenance treatment. Conclusions: Weekly ketamine dosing was safe and well tolerated, and post-dose dissociative symptoms tended to reduce after repeated dosing. Patients reported marked improvements in functionality and in their personal lives. Maintenance ketamine may be a therapeutic alternative for patients with treatment refractory GAD/SAD. Trial Registration: http://www.anzctr.org.au/ACTRN12615000617561

Topics

Anxiety, Depression, Psychometrics, Treatment, Cognitive Processes Treatment of Major Depression Tryptophan and brain disorders

Categories

Health Sciences Medicine Pharmacology

Tags

Adverse effect Anesthesia Anxiety Astrobiology Blurred vision Dosing Generalized anxiety disorder Hamilton Anxiety Rating Scale Internal medicine Ketamine Medicine Nausea Physics Psychiatry Psychology Refractory (planetary science) Social anxiety Tolerability

Substances

Ketamine

Conditions & symptoms

Anxiety Anxiety or worry Feeling disconnected from others