KETAMINE

Multiple meta-analyses confirm that both racemic ketamine (IV) and esketamine (intranasal) produce rapid antidepressant effects in treatment-resistant depression, with IV ketamine showing greater response and remission rates than intranasal esketamine. IV ketamine demonstrates efficacy at doses as low as 0.2 mg/kg, with increasing response up to 0.5 mg/kg but no additional benefit at 1 mg/kg. Common side effects are generally transient and include dissociation, nausea, headache, elevated heart rate, and blood pressure. Long-term safety data remain limited; high-dose or frequent use is associated with cognitive impairment and lower urinary tract pathology. The identification of reliable predictors of individual response remains an active area of research, with most known predictors showing only modest effect sizes.