Prevalence and predictors of high-dose antipsychotic therapy among adult psychiatric inpatients in Baghdad, Iraq

Background: Current evidence-based guidelines recommend the use of antipsychotic monotherapy at the lowest effective dose. Nonetheless, high-dose antipsychotics and antipsychotic polypharmacy appear to be common in clinical practice, often deviating from established recommendations. Aim: This study aimed to estimate the prevalence and factors associated with high-dose antipsychotic prescribing among adult psychiatric inpatients. Setting: The study was conducted at Ibn Rushd Psychiatric Teaching Hospital in Baghdad, Iraq. Methods: The medical records of inpatients admitted from 24 April 2023 to 12 September 2023, were retrospectively analysed to extract routinely collected patient-level data and medication details; dosing appropriateness was based on that stated in the British National Formulary. Results: Of the 225 eligible patients, 51.1% were male, aged 18-82 years (mean = 33.9). Altogether, 48.6% of patients received antipsychotic polypharmacy, and 35.6% were prescribed high-dose antipsychotics. No significant associations were found between high-dose antipsychotic prescribing and patients' characteristics, including age, sex, length of hospital stay, and number of admissions. Predictors of high-dose antipsychotics were polypharmacy (adjusted odd ratio [AOR]:12.61; 95% confidence interval [CI]: 1.78, 89.50), first-generation antipsychotics (AOR: 7.049; 95% CI 1.33, 37.44), quetiapine (AOR: 5.66; 95% CI 1.16, 27.53), procyclidine (AOR: 0.17; 95% CI 0.05, 0.55), and antidepressants (AOR: 0.19; 95% CI 0.05, 0.76). Conclusion: Approximately one in three patients received regular high-dose antipsychotic therapy, which contradicts optimal clinical practice and risks patient safety. Targeted educational interventions are warranted to enhance guideline adherence and promote safe and appropriate use of antipsychotics. Contribution: This is the first study to assess the magnitude and factors associated with high-dose antipsychotic prescription in Iraq.