Department of Pharmacy, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China; Hubei Province Clinical Research Centre for Precision Medicine for Critical Illness, Wuhan, China. Electronic address: zhaixuejia@163.com.
2 papers in the library · 6 citations · publishing 2025
After intranasal administration in rats, ketamine rapidly enters the bloodstream, reaching a peak concentration of 8002 ng/mL within about 5 minutes, then declines to near zero by about 3 hours, with a half-life of 27 minutes. Tissue analysis shows the highest ketamine levels in the kidneys, followed by the liver. Within the brain, ketamine concentrates most in the hypothalamus and hippocampus, with lower amounts in the striatum and prefrontal cortex. These findings clarify how ketamine distributes throughout the body and brain after intranasal delivery, providing a basis for understanding its clinical use in treating depression.
Older adults (65 years or older) treated with esketamine experience a higher risk of severe psychiatric and general adverse events compared to younger adults. Analysis of FDA Adverse Event Reporting System data from 2019 to 2024, covering 536 reports from older adults and 3,566 from younger adults, found that older adults had a higher incidence of dissociation, suicidal ideation, depression, and anxiety. They also reported more general and administration site conditions, indicating greater susceptibility to systemic and local reactions. Gastrointestinal and respiratory disorders were less frequent in older adults, but their potential impact remains critical. These findings highlight the need for careful patient selection, monitoring, and tailored treatment protocols for older adults receiving esketamine.