September 29, 2010 (Las Vegas, Nevada) — A single subanesthetic dose of intravenous ketamine administered to acutely depressed and suicidal patients presenting to the emergency department (ED) can rapidly alleviate depression and can alleviate suicidal thoughts for up to 10 days, according to a study presented here at the American College of Emergency Physicians 2010 Scientific Assembly.

The study involved 15 patients who presented to the ED with a primary complaint of depression and/or suicidal ideation. Results showed that all patients who were administered a single subanesthetic intravenous bolus of ketamine (0.20 mg/kg over 1 to 2 minutes) had decreased suicidal ideation at 40, 80, 120, and 240 minutes postinfusion. Suicidal ideation was completely resolved in 14 of the 15 subjects within 40 minutes, and was sustained at 10-day follow-up in 13 of the 14 patients.

Previous studies have looked at ketamine as a treatment for depression. Researchers from the Yale University School of Medicine's Department of Emergency Medicine, in New Haven, Connecticut, decided to evaluate the drug's fast-acting potential.

"Currently there is no good pharmacotherapy for the treatment of acute depression or suicide ideation. However, several studies have shown that ketamine may exert effects on patients who present with depression," said coauthor Robert Turelli, MD.

The study's findings, although preliminary, are promising, Dr. Turelli said. "Our study is the first to show that a reduction in depressive systems can be achieved with a rapid bolus, which is a more feasible application in a busy ED setting," he said.

"There was no sign of remission of any of the suicidal thoughts among patients who underwent the study in the 10 days of follow-up." Dr. Turelli added.

Patients' moods were evaluated at baseline on the Montgomery-Åsberg Depression Rating Scale (MADRS) and the Beck Scale for Suicidal Ideation (SSI)

Scores were 42 (range, 38 to 47) for MADRS and 19 (range, 12 to 28) for Beck's SSI. Mean MADRS scores at baseline, and at 40, 80, 120, and 240 minutes postinfusion were 41.5,14.9, 13.6, 12.2, and 12.0, respectively (repeated-measures analysis of variance; P < .0001).

Mild positive psychotic-like symptoms or adverse effects were experienced, but all resolved within 40 minutes. Two patients experienced significant unpleasant dissociative symptoms, but those resolved within 30 minutes.

The patients did not have a significantly longer ED stay than 15 age- and diagnosis-matched control subjects who did not receive the drug.

The patients all endorsed the statement that "the benefits of receiving this medication outweigh any inconvenience, discomfort, or side effects."

The study's limitations include the small number of patients and the lack of a placebo group, but Dr. Turelli said the findings suggest a potentially important new use for the drug.

"Despite the small numbers, these results are dramatic and very impressive, suggesting that ketamine is feasible and possibly beneficial for the emergency setting."

According to Michael P. Wilson, MD, PhD, from the Department of Emergency Medicine at University of California at San Diego, the findings are significant in suggesting a potentially valuable, fast-acting use for the drug in depressed patients.

"The study is unique in showing that the drug can be given safely in the emergency department for depressed patients. The study authors also gave the drug rapidly, instead of at a low dose over a long period of time," Dr. Wilson said.

"You would expect that such a low dose wouldn't work for most patients, but the drug made people feel better — 100% of them — so it's really an interesting study and it seems that it might be a very exciting tool."

The study was supported by funding from the Connecticut College of Emergency Physicians. Dr. Turelli and Dr. Wilson have disclosed no relevant financial relationships.

American College of Emergency Physicians (ACEP) 2010 Scientific Assembly: Abstract 157. Presented September 28, 2010.