A replication study using the World Health Organization pharmacovigilance database (VigiBase®) to evaluate whether an association between ketamine and esketamine and alcohol and substance misuse exists.

ABSTRACT

BACKGROUND AND OBJECTIVES: Ketamine and esketamine are increasingly prescribed in the treatment of resistant mood disorders and persons at risk of suicide. Ketamine is a drug of misuse with increasing non-therapeutic use in the general population. Herein, our aim was to determine whether ketamine and/or esketamine are disproportionately associated with reports of substance and/or alcohol misuse. METHODS: Replicating a similar analysis recently conducted using the Food and Drug Administration Adverse Event Reporting System (FAERS) database, we identified cases of "alcohol problem, alcoholism, alcohol abuse, substance dependence, substance use disorder (SUD), substance abuse, drug dependence, drug use disorder and drug abuse" in association with ketamine and esketamine reported to the World Health Organization Pharmacovigilance Database (WHO VigiBase). We searched the database from inception to January 2024. The reporting odds ratio (ROR) of each of the aforementioned parameters was calculated; acetaminophen was used as the control. The numerator of the equation represents the number of cases (n) and the denominator represents the total cases of psychiatric disorders (N). Significance was obtained when the lower limit of the 95 % confidence (CI) > 1.0. RESULTS: The RORs for ketamine was increased for most parameters (i.e., alcohol abuse (3.24), substance dependence (12.48), substance use disorder (170.44), substance abuse (2.94), drug dependence (2.88), drug use disorder (11.54) and drug abuse (2.85), respectively). With respect to esketamine, the RORs were observed to be different from ketamine insofar as we observed a reduction in the RORs for three parameters (i.e., substance abuse (0.41), drug dependence (0.083) and drug abuse (0.052), respectively). The IC025 values were significant for ketamine in cases of alcohol abuse (0.35), substance dependence (0.50), substance use disorder (2.77), substance abuse (0.83), drug dependence (0.97), drug use disorder (1.95) and drug abuse (0.94). Additionally, oxycontin showed significant IC025 values for substance use disorder (0.0014), substance abuse (0.042), and drug dependence (0.17). CONCLUSION: Esketamine was not associated with an increased ROR for any parameter of alcohol and/or substance use disorder. Mixed results were observed with ketamine with some RORs increased and others decreased. Estimating RORs using a pharmacovigilance database does not establish causation in the case of elevated RORs and cannot be assumed to be a therapeutic effect when lower RORs were observed.