ZypAdhera ® (olanzapine pamoate monohydrate)

ZypAdhera® (olanzapine pamoate): Measurement of Plasma Concentration

During treatment, dose may subsequently be adjusted on the basis of individual clinical status. Posology based on the Summary of Product Characteristics does not require mandatory measurement of plasma concentrations.

Further Information

After repeated intramuscular (IM) injections with 150 to 300 mg olanzapine pamoate every two weeks, the 10th to 90th percentile of steady-state plasma concentrations of olanzapine were between 4.2 and 73.2 ng/ml.1

The plasma concentrations of olanzapine observed across the dose range of 150 mg every 4 weeks to 300 mg every 2 weeks illustrate increased systemic olanzapine exposure with increased olanzapine pamoate doses.1

Olanzapine plasma clearance after oral olanzapine is lower in females (18.9 l/hr) versus males (27.3 l/hr), and in non-smokers (18.6 l/hr) versus smokers (27.7 l/hr). Similar pharmacokinetic differences between males and females and smokers and non-smokers were observed in olanzapine pamoate clinical trials. However, the magnitude of the impact of gender, or smoking on olanzapine clearance is small in comparison to the overall variability between individuals.1

The combination of the release profile and the dosage regimen (intramuscular injection every two or four weeks) result in sustained olanzapine plasma concentrations. Plasma concentrations remain measurable for several months after each olanzapine pamoate injection.1

In the olanzapine pamoate clinical trials, blood samples for the assessment of olanzapine plasma concentration samples were collected immediately prior to administration of olanzapine pamoate at that visit, thus reflecting trough olanzapine concentration. 2,3 


1. ZypAdhera [summary of product characteristics]. Eli Lilly Nederland B.V., The Netherlands.

2. Kane JM, Detke HC, Naber D, et al. Olanzapine long-acting injection: a 24-week, randomized, double-blind trial of maintenance treatment in patients with schizophrenia. Am J Psychiatry. 2010;167(2):181-189. http://dx.doi.org/10.1176/appi.ajp.2009.07081221

3. McDonnell DP, Landry J, Detke HC. Long-term safety and efficacy of olanzapine long-acting injection in patients with schizophrenia or schizoaffective disorder: a 6-year, multinational, single-arm, open-label study. Int Clin Psychopharmacol. 2014;29(6):322-331. http://dx.doi.org/10.1097/YIC.0000000000000038

Date of Last Review: April 12, 2021

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