Correlation between steady-state plasma concentrations (Css) of bromperidol and haloperidol

Area of Science:

• Pharmacology
• Psychiatry
• Clinical Chemistry

Background:

• Bromperidol is a structural analogue of haloperidol with similar metabolic pathways.
• Understanding the relationship between their plasma concentrations is crucial for effective treatment.

Purpose of the Study:

• To investigate the correlation between the steady-state concentrations (Css) of bromperidol and haloperidol in patients with schizophrenia.
• To assess the relationship between the Css of their reduced metabolites.

Main Methods:

• A pharmacokinetic study involving 16 schizophrenic inpatients.
• Patients received either bromperidol or haloperidol (12 mg/day) sequentially.
• High-performance liquid chromatography (HPLC) was used to measure drug and metabolite Css after 2-3 weeks of treatment.

Main Results:

• No significant correlation was found between the Css of bromperidol and haloperidol (r = 0.246).
• Similarly, no significant correlation was observed between the Css of their reduced metabolites (r = 0.142).

Conclusions:

• The steady-state concentrations of bromperidol and haloperidol do not correlate well in individual schizophrenic patients.
• This implies that therapeutic drug monitoring may need to consider individual patient variability for these antipsychotics.