[Therapeutic drug monitoring of olanzapine]

Association between olanzapine plasma concentrations and treatment response: A systematic review, meta-analysis and individual participant data meta-analysis

AIMS

By meta-analysing pooled studies and available individual participant data, we aim to provide new insight on olanzapine therapeutic drug monitoring in schizophrenia.

METHOD

We conducted a computerized search of bibliographic databases (Pubmed, Cochrane library, Web of Science and PsycINFO) to identify studies that assessed the relationship between olanzapine plasma concentration and the change in patients' clinical scores. We investigated this relationship with olanzapine plasma level 12h00 post-intake using a random-effects model.

RESULTS

7 studies were included in the pooled data analysis (781 patients). We found no difference in oral dose between responders and non-responders but a significantly higher concentration of 4.50 µg/L in responders (p < 0.01). Olanzapine concentration above the thresholds identified in each study was associated with response (odd ratio = 3.50, p = 0.0007). We identified that non-responder patients showed greater inter-individual variability than responders. In the individual data analysis (159 patients), we found no relationship between dose and clinical response but an association between plasma level and response in the shape of a parabolic curve. The Receiver Operating Characteristic curve found a threshold of 22.07 µg/L to identify responders (96% sensitivity, 86% specificity) and a threshold of 56.47 µg/L to identify a decreased probability of response.

CONCLUSION

In contrast to oral dose, our work confirmed that plasma olanzapine levels are associated with clinical response and should therefore be used to optimise treatment. We determined a treatment response threshold of 22.07 µg/L and suggest that a concentration above the therapeutic window may result in a decreased response.

Simultaneous quantification of 55 psychotropic drugs and metabolites in human plasma with a fast UPLC-MS/MS method

OBJECTIVES

Therapeutic drug monitoring is strongly recommended for psychotropic drugs, which present a strong inter- and intra-individual variability due to multiple factors like inflammatory state, smoking, diet, drug interactions due to polypharmacy, and genetic profile. The aim of this study was to develop and validate a fast, simple, and sensitive method allowing the simultaneous quantification of a large number of psychotropic drugs.

METHODS

After a simple sample preparation with a one-step protein precipitation, a total of 55 compounds, including 22 antidepressants, 18 antipsychotics, 2 other psychotropic drugs (bupropion and nefopam), and their metabolites, was separated on a Waters Acquity HSS T3 ultra-performance liquid chromatography column, and subsequently detected and quantified by a triple quadrupole Quantis mass spectrometer with electrospray ionization operated in positive mode.

RESULTS

Total run time was only 5.7 min. Limits of detection ranged from 0.01 to 0.18 µg/L depending on compound. Measuring ranges were from 0.195 to 1000 µg/L depending on compound, and were defined according to therapeutic ranges. Inter- and intra-assay precisions values were less than 15 %. After validation, this method was successfully applied in daily practice for therapeutic drug monitoring of polymedicated psychiatric patients.

CONCLUSION

We developed and validated one of the most sensitive and complete UPLC-MS/MS methods in psychopharmacology, allowing the simultaneous determination of 55 psychotropic drugs in only 5.7 min after a simple sample preparation. This method has been successfully used in daily practice for therapeutic drug monitoring of psychiatric patients and is especially useful in polymedicated patients.

Role of olanzapine in chemotherapy-induced nausea and vomiting on platinum-based chemotherapy patients: a randomized controlled study

PURPOSE

Even with the use of modern antiemetic drugs, chemotherapy-induced nausea and vomiting (CINV) is still a cause of great distress to the patients. Olanzapine, primarily marketed as an antipsychotic, was found to reduce nausea and vomiting in some chemotherapy patients. But it was never tested in Indian population with a diverse genetic background. The present study aims to evaluate the role of olanzapine in CINV in patients receiving platinum-based chemotherapy.

METHODS

The study was a randomized, controlled, assessor-blinded study on 100 chemotherapy-naïve consenting patients receiving any one from cisplatin, carboplatin or oxaliplatin. The control group (n = 50) received palonosetron and dexamethasone in the approved therapeutic dose from the day 1 of chemotherapy. The test group (n = 50) received additional olanzapine 10 mg/day from day 1 for five consecutive days. CINV and quality of life (QoL) were assessed.

RESULTS

Vomiting was significantly less among the olanzapine-treated patients. Control of delayed emesis was significantly better in this group (complete response among 96 vs. 42 % in the control group, p value <0.0001). Incidence and severity of nausea was significantly less in this group. Failure of anti-CINV measure was 4 % in this group compared to 26 % of the patients of the control group during overall days 1-5. Though sedation was more in these olanzapine-treated patients, there was no dose-limiting adverse event. Quality of life was also better among the olanzapine-treated patients.

CONCLUSION

Olanzapine was found to be effective as add-on in the control of CINV.