Comparative Risk of Hyponatremia Among Patients Treated With Second-Generation Antipsychotics

Area of Science:

• Pharmacovigilance
• Clinical Epidemiology
• Psychiatry

Background:

• Hyponatremia is a known adverse event linked to second-generation antipsychotic (SGA) medications.
• Comparative data on hyponatremia risk among individual SGAs is limited, hindering informed clinical decisions.

Purpose of the Study:

• To compare the risk of hyponatremia associated with various second-generation antipsychotics.
• To identify specific SGAs with potentially lower hyponatremia risk.

Main Methods:

• Retrospective cohort study utilizing large databases: US FDA Adverse Event Reporting System (FAERS) and a Japanese hospital claims database (Medical Data Vision).
• New-user design including patients aged 18-69 with no prior history of antipsychotics or hyponatremia.
• Disproportionality analysis (reporting odds ratios) and incidence analysis (adjusted hazard ratios) comparing SGAs to olanzapine.

Main Results:

• In the FAERS database, most SGAs had lower reporting odds ratios for hyponatremia than olanzapine.
• In the Japanese claims database (n=55,394), aripiprazole was associated with a significantly lower risk of hyponatremia compared to olanzapine (aHR, 0.52; 95% CI, 0.35-0.76).
• Other SGAs did not show significant differences in hyponatremia risk compared to olanzapine.

Conclusions:

• Aripiprazole may be associated with a reduced risk of hyponatremia compared to olanzapine among antipsychotic users.
• These findings can aid clinicians in selecting antipsychotics, particularly for patients at higher risk of hyponatremia.
• Further research should consider residual confounding factors.