Evidence map›Paper›PMID 41420713›Full record

ArticleEuropean journal of clinical pharmacology2025

Antipsychotic load during olanzapine mono- versus polytherapy and in relation to age.

Vigdis Solhaug, Ragnhild Birkeland Waade, Lene Jansrud, Espen Molden, Elisabet Størset, Gudrun Høiseth, Marit Tveito

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Article in European journal of clinical pharmacology, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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1 · What the graph read from it

What it found

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2 · The registry

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3 · Its place in the literature

Who cites it

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4 · The record

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5 · Who and what money

Authors and funding

7 authors.

Vigdis SolhaugCenter for Psychopharmacology, Diakonhjemmet Hospital, PO Box 85, Vinderen, Oslo, 0319, Norway. vigdis.solhaug@diakonsyk.no.ORCID http://orcid.org/0000-0002-4138-9273
Ragnhild Birkeland WaadeCenter for Psychopharmacology, Diakonhjemmet Hospital, PO Box 85, Vinderen, Oslo, 0319, Norway.ORCID http://orcid.org/0000-0003-0720-1780
Lene JansrudDepartment of Pharmacy, University of Oslo, Oslo, Norway.
Espen MoldenCenter for Psychopharmacology, Diakonhjemmet Hospital, PO Box 85, Vinderen, Oslo, 0319, Norway.ORCID http://orcid.org/0000-0001-6190-2751
Elisabet StørsetCenter for Psychopharmacology, Diakonhjemmet Hospital, PO Box 85, Vinderen, Oslo, 0319, Norway.ORCID http://orcid.org/0000-0002-2662-8504
Gudrun HøisethCenter for Psychopharmacology, Diakonhjemmet Hospital, PO Box 85, Vinderen, Oslo, 0319, Norway.ORCID http://orcid.org/0000-0003-0872-9536
Marit TveitoCenter for Psychopharmacology, Diakonhjemmet Hospital, PO Box 85, Vinderen, Oslo, 0319, Norway.ORCID http://orcid.org/0000-0003-3963-4759

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

purposeWhile antipsychotic monotherapy is generally recommended in treatment of psychotic disorders, polytherapy is frequently observed in clinical practice. We aimed to investigate the total antipsychotic load among patients treated with olanzapine in monotherapy vs. polytherapy, and how the antipsychotic load changed in relation to age.

methodsPatients with serum concentration measurements of olanzapine alone (monotherapy) or in combination with other antipsychotics (polytherapy) were retrospectively included from a therapeutic drug monitoring service. The antipsychotic load was measured as olanzapine dose and concentration equivalents. Patients were categorised into three age groups (18–49 years, 50–74 years and ≥ 75 years of age).

resultsIn total, 10 190 patients (54% males) were included, whereof 8 759 (86%) received olanzapine in monotherapy and 1 431 (14%) in polytherapy. The mean olanzapine dose equivalent was significantly higher in the polytherapy group compared to the monotherapy group (23.0 vs. 11.1 mg, p < 0.001). Likewise, the mean concentration equivalent was higher in the polytherapy group than in the monotherapy group (179 vs. 89.1 nmol/L, p < 0.001). When comparing patients ≥ 75 years with patients 18–49 years, the mean dose equivalents were 43% and 41% lower in the monotherapy and polytherapy group, respectively (both p < 0.001), whereas the respective concentration equivalents were only 11% (p < 0.001) and 10% (p = 0.141) lower.

conclusionPatients receiving olanzapine in antipsychotic polytherapy had twice as high antipsychotic load compared to patients using olanzapine monotherapy, both in terms of olanzapine dose and concentration equivalents. Although the antipsychotic doses were reduced by age, the concentration levels remained similar.

Indexed as

Antipsychotic AgentsOlanzapinePsychotic DisordersAdolescentAdultAgedAge FactorsBenzodiazepinesDrug MonitoringDrug Therapy, CombinationFemaleHumansMaleMiddle AgedRetrospective StudiesYoung AdultAntipsychotic AgentsBenzodiazepinesOlanzapineAgingAntipsychoticsPharmacokineticsPolypharmacyTherapeutic drug monitoring

Identifiers

PMID41420713
PMCPMC12718314

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