Ketamine is rapidly metabolized, with a drug elimination half- life of 2.5 hours. Headache and nausea are common and transient side effects. Based on the FDA-registered clinical trials, the average maximum increase in systolic and diastolic blood pressures after ketamine/ esketamine administration have been reported to be between 11.6– 15.0 mmHg and 8.9–9.4 mmHg, respectively, at 40 minutes after the treatment, generally resolving by 1–2 hours. On occasion, clinicians use an oral antihypertensive (i.e. labetalol) pre-treatment to mitigate ketamine-related hypertension.

Publication reference : Nikayin S, Murphy E et al. Long-term safety of ketamine and esketamine in treatment of depression. Expert Opin Drug Saf 2022; 21: 777-787.
Reference URL: https://pubmed.ncbi.nlm.nih.gov/35416105/