Safety outcomes of ketamine for treatment-resistant depression in clinical settings and development of the ketamine side effect tool-revised (KSET-R).

BACKGROUND

Ketamine and its derivates (e.g. esketamine) are increasingly used in clinical settings for treatment-resistant depression (TRD). Ketamine can give rise to acute, cumulative and longer-term side effects (SEs) across a treatment course. The Ketamine Side Effect Tool (KSET) examines adverse effects though its length has affected feasibility for use in clinical settings.

OBJECTIVE

To estimate the frequency of ketamine SEs occurring in real-world settings using the KSET, additional validated scales and laboratory measures. Utilising this naturalistic data, to develop a shorter, more feasible and validated tool (KSET-Revised; KSET-R).

METHODS

Retrospective patient and safety data from three outpatient services were collected which included KSET symptom questions, standardised scales and laboratory measures. We calculated frequency of SEs occurring intra-session, intersession and at follow-up. Revision of the KSET included removal of items based on a priori criteria. Construct and concurrent validity were examined by comparison of specific KSET items and the overall tolerability rating with standardised scales.

RESULTS

Descriptive statistics including SE frequencies are reported and the KSET-R is detailed: a shorter tool with construct and concurrent validity for specific items, along with the overall tolerability rating.

LIMITATIONS

small sample size for follow-up data; predominantly subcutaneous racemic and intranasal esketamine analysed - other routes and formulations not examined; and subjective not objective cognition measured.

CONCLUSIONS

Naturalistic data gives an estimate of frequency of ketamine SEs within session, between sessions and at follow-up. The KSET-R has improved feasibility and clinical utility and is recommended for use in clinical practice where ketamine is prescribed.