NEW ORLEANS –
“These were patients with depression who had not responded even to intensive therapies or procedures, and we found that after a 6-week ketamine infusion regimen, there was no difference in the response to the treatment between the treatment-resistant geriatric and nongeriatric patients,” study investigator Jonathan Kim, of Emory University, Atlanta, the first author of one of two studies presented as part of the American Association for Geriatric Psychiatry annual meeting, said in an interview.
The findings are important because research on the effects of IV ketamine have not been well documented in geriatric patients, who have high rates of depression and TRD.
“There is a lack of data on IV ketamine in older adults with treatment-resistant depression, and there are some safety and tolerability concerns which may lead some older adults and their clinicians to be reluctant to pursue IV ketamine treatment,” study coinvestigator Hanadi Ajam Oughli, MD, a health sciences assistant clinical professor in the department of psychiatry and biobehavioral sciences, University of California, Los Angeles, told this news organization.
Nasal vs. IV administration
Ketamine has traditionally been used as an anesthetic that blocks N-methyl-D-aspartate (NMDA) glutamate receptors, Dr. Oughli and colleagues note.
In the treatment of TRD, an infusion of 0.5 mg/kg is typically administered over 40 minutes, producing a rapid antidepressant response. Recent research shows the drug reduces suicidality and improves mood and quality of life.
A more recent intranasal formulation of ketamine, esketamine, was approved by the U.S. Food and Drug Administration for TRD in 2019, and some experts questioned its path to approval. In addition, the drug’s high cost and poor bioavailability in comparison with IV ketamine remains an issue, said Dr. Oughli.
In the previous TRANSFORM-3 study, a placebo-controlled randomized trial, there was no difference between esketamine, used in conjunction with an antidepressant, and placebo for geriatric patients.
To better understand the effects of IV ketamine in this patient population, Mr. Kim’s team conducted a retrospective chart review of 91 older patients with TRD who received IV ketamine treatment between October 2016 and August 2022.
Patients were divided into two groups – those older than 60 years (n = 36; 44% women; mean age, 68.86) and those younger than 60 (n = 55; 49% women; mean age, 41.05). Participants in each age group received six ketamine infusions over 6 weeks.
Results showed that with regard to depression severity, as assessed using Beck Depression Inventory (BDI-II) scores, 27.8% of patients in the geriatric group had a 50% or greater improvement, vs. 25.4% of those younger than 60.
The average BDI-II scores represented a significant improvement for both groups (P < .01), and the difference in scores between the groups was not statistically significant (P = .973).
“It is important to note that our study was conducted in a real-world clinical setting with a treatment-resistant population; other clinical studies may not have such sick patients in their trials. Additional studies are therefore warranted to establish further treatment guidelines in this area,” Mr. Kim said.