Treating Major Depression | Ketamine has long been used to relieve pain, and more recently has been utilized to treat major depression. Now doctors at Cedars-Sinai Medical Center in Los Angeles, California, are using it to help patients suffering from both conditions together.
The comorbidity of depression and chronic pain is on the rise, and it became clear that new and creative interventions were needed, said Waguih William IsHak, MD, vice chairman for research and education, Department of Psychiatry, Cedars-Sinai. Dr. IsHak and colleagues discussed their approach with a standing-room only crowd at the American Psychiatric Association’s annual meeting Tuesday.
Over the last year, the group has used ketamine on 45 patients hospitalized for chronic pain who also have depression. They have started to collect and assemble data on the results, and hope to have figures to make public soon, Dr. IsHak said. Results will be measured using pain scales and the Patient-Reported Outcomes Measurement Information System (PROMIS).
The patients are typically in the hospital because of an acute exacerbation of chronic pain, usually in the abdomen, said Charles Louy, MD, medical director of the Inpatient Pain Service and associate director of the Pain Medicine Fellowship at Cedars-Sinai, a 1000-bed facility. Exclusion criteria include hypertension, cardiac disease, and arrhythmias.
The ketamine is given through infusions, and the typical dose has been .5 mg/kg per hour for 3 hours. The team has experimented with lower doses and durations of up to 6 hours.
There is a paucity of literature on specific optimal doses of ketamine, Dr. Luoy said.
Brigitte Vanle, PhD, a resident at Cedars-Sinai, said there have been no formal trials that tested ketamine’s effects on comorbid pain and depression.
Cedars-Sinai resident Jonathan Dang, MD, presented a review published in 2017 suggesting that the duration of a ketamine infusion could be directly proportional to the length of a patient’s relief from pain. Intensive care unit patients who had a continuous 4- to 5-day infusion of ketamine demonstrated pain relief for 6 weeks to 6 months.
Dr. Louy said one of the doctors’ initial concerns was the patients becoming tachycardiac when receiving the ketamine.
“Interestingly, the tachycardia concern did not materialize, and 99% of the time the patient’s heart rate actually drops,” he said. “We postulated that this is due to the fact that they become analgesic, and so there’s less concomitant stimulation to cause tachycardia.”
Patients experiencing hallucinations is another concern among the doctors, and in some cases they give an additional medication to limit hallucinations. After receiving a ketamine infusion, one patient said she pictured falling through an empty shaft; but, she also said it didn’t bother her. Dr. Luoy said.
Another concern is how to maintain treatment over the long term, as ketamine has a short half-life, especially as a depression treatment.
“That’s the biggest challenge we’ve had,” Dr. IsHak said. “We’ve had these remarkable responses on IV. Then ‘now what?’ “
Scott Irwin, MD, PhD, director of the supportive care services at the Samuel Oschin Cancer Center at Cedars-Sinai, said he believes oral ketamine is the best option, noting it is cheaper than infusions.
