Evidence map›Paper›PMID 40924145›Full record

ArticleEuropean journal of clinical pharmacology2025

Influence of ultrafiltration conditions on the unbound fraction of phenytoin and valproic acid.

Pjotr P Temme, Matthijs van Luin, Maarten J Deenen, Ron Meijer, Nynke G L Jager, Mirte M Malingré

Abstract read
PubMed Publisher
In one paragraph

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.

0numbers the graph read from it
0cells of the map it votes in
0citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

6 authors.

Pjotr P TemmeDepartment of Hospital Pharmacy, Meander Medical Centre, Amersfoort, the Netherlands. pp.temme@meandermc.nl.ORCID http://orcid.org/0000-0003-0157-4682
Matthijs van LuinDepartment of Hospital Pharmacy, Meander Medical Centre, Amersfoort, the Netherlands.ORCID http://orcid.org/0000-0001-6172-887X
Maarten J DeenenDepartment of Clinical Pharmacy, Catharina Hospital, Eindhoven, the Netherlands.ORCID http://orcid.org/0000-0002-4389-6420
Ron MeijerFoundation for Quality Assessment in Medical Laboratory Diagnostics (SKML), Nijmegen, the Netherlands.
Nynke G L JagerDrug Analysis and Toxicology Division (KKGT) Section of the Dutch Foundation for Quality Assessment in Medical Laboratories (SKML), Nijmegen, the Netherlands.ORCID http://orcid.org/0000-0002-4524-9892
Mirte M MalingréDepartment of Hospital Pharmacy, Meander Medical Centre, Amersfoort, the Netherlands.ORCID http://orcid.org/0000-0002-2531-3623

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

purposeThis study was designed to analyse the influence of temperature, pH and storage time on unbound fractions of PHT and VPA.

methodsThe influence of ultrafiltration (UF) temperature on measured unbound fractions of PHT and VPA in spiked samples was evaluated in a single laboratory experiment and in data from a national external quality control (EQC) database. The influence of pH adjustment with phosphate buffered saline (PBS) on measured unbound fractions of PHT and VPA was investigated in patient samples. The influence of storage time on unbound fractions of PHT and VPA was examined in patient samples by performing UF at various time points.

resultsPerforming UF at a temperature of 37 °C compared to 20 °C significantly increased (p < 0.05) the measured unbound fractions for both PHT (range 14.8-26.3%) and VPA (range 5.7-16.0%) in the single laboratory experiment. Consistent with these findings, reported unbound fractions in the ECQ database of PHT were significantly higher with UF at 37 °C compared to room temperature. For VPA, this was not the case. However, for both drugs, the number of laboratories performing UF at 37 °C was limited (n = 2-4). Adjustment of pH with PBS was unfeasible. After 4 days of storage at 5 °C, the unbound fraction of PHT seemed to remain stable whereas the unbound fraction of VPA appeared to increase (27.4%) (n = 3).

conclusionHigher UF temperatures led to an increase in measured unbound fractions of both PHT and to a lesser extent VPA. Storage time of plasma samples might influence the unbound fraction of VPA.

Indexed as

AnticonvulsantsPhenytoinValproic AcidDrug StorageHumansHydrogen-Ion ConcentrationTemperatureTime FactorsUltrafiltrationAnticonvulsantsPhenytoinValproic AcidPhenytoinUltrafiltration conditionsUnbound fractionValproic acid

Identifiers

What OpenQuestion holds

Textmetadata
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.