Over the past 15 years, there have been many reports into the efficacy of ketamine for treating depression, but very few original studies of its safety.
Lancet Psychiatry (online, 27 July 2017), researchers performed a systematic review of 60 studies including 899 patients who had received ketamine
The researchers found that acute side effects were common and included headache, dizziness and elevated blood pressure, as well as psychiatric side effects such as anxiety. They also observed that the majority of side effects were associated with ketamine given intravenously and occurred immediately after single-dose administration.
Most studies were not placebo-controlled and only 12 (20%) assessed long-term side effects.
The researchers say that large-scale clinical trials with multiple doses of ketamine, long-term follow-up and reporting of all side effects are needed to assess the safety of ketamine before it is used as a widespread treatment for depression.