A substantial proportion of patients with obsessive-compulsive disorder (OCD) do not respond to first-line treatments. Ketamine and esketamine, NMDA receptor antagonists with rapid antidepressant effects, have attracted interest as potential treatments. This scoping review of 21 studies (5 preclinical, 16 clinical) found that preclinical evidence suggests ketamine and esketamine improve compulsive-like behaviors. Clinical studies suggest ketamine can produce rapid reductions in obsessive symptoms, though results remain inconsistent. Most trials evaluated single administrations; limited evidence suggests repeated dosing may provide greater benefit. The evidence remains preliminary and heterogeneous, and future research should prioritize adequately powered randomized trials with repeated dosing and longer follow-up.
A single intravenous dose of (R)-ketamine hydrochloride, ranging from 10.0 mg to 180 mg, was safe and well tolerated in healthy Chinese subjects. Adverse events were temporary and resolved without treatment. The peak plasma concentrations of (R)-ketamine and its metabolite (R)-norketamine increased roughly in proportion to the dose, with average peak levels ranging from 56.0 to 1424 ng/mL and 27.7 to 491 ng/mL, respectively. These results support further clinical studies of this rapid-acting antidepressant for treatment-resistant depression.
Decoctions made from Mimosa hostilis and Peganum harmala, plants sometimes used as substitutes in ayahuasca, can kill human colorectal adenocarcinoma cells in the lab. The extracts triggered programmed cell death (apoptosis) and slowed cell growth. They also lowered oxidative stress and boosted activity of the antioxidant enzyme glutathione peroxidase, while superoxide dismutase activity remained unchanged. The findings suggest these plant decoctions have potential anticancer properties against colorectal cancer cells.