Mixed Findings for Intranasal Ketamine
The drug ketamine can rapidly and temporarily improve depression when delivered intravenously. Researchers have been working on extending ketamine’s effects and finding easier ways of delivering the medication. One new delivery method under investigation is nasal spray, which could be used repeatedly to extend ketamine’s effects.
Unfortunately, researcher Colleen Loo reported in the Journal of Psychopharmacology in 2018 that a pilot study of self-administered intranasal ketamine for severe depression was suspended when 5 of the 10 participants had side effects that included high blood pressure, psychotic symptoms, and motor incoordination that made them unable to keep using the spray. Early in the four-week study, dosage was adjusted to leave more time between sprays, but this was not enough to prevent the problems with side effects.
Loo said that the nasal spray version of ketamine has complications including variations in absorption among different people and on different days, depending on factors like mucus in the nose and exact application techniques. Its rapid absorption into the bloodstream could lead to high peak levels in certain people.
Loo and colleagues had previously found that elderly patients receiving injections of ketamine under the skin required highly individualized dosing to avoid side effects. This may also be the case with nasal spray.
While Loo’s study found intranasal ketamine infeasible for the moment, Janssen Research and Development, a pharmaceutical company owned by Johnson & Johnson, reported positive results in phase 3 clinical trials of intranasal esketamine (a component of ketamine) at the annual meeting of the American Psychiatric Association in May. Researchers for Janssen reported that intranasal esketamine was highly effective for depression and well-tolerated both in acute treatment and over a year-long period. Janssen is now pursing approval for the drug from the US Food and Drug Administration.
