ArticleBritish journal of clinical pharmacology2010
The 'apparent clearance' of free phenytoin in elderly vs. younger adults.
Article in British journal of clinical pharmacology, 2010. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 1 paper.
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.
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.
Who cites it
1 citing paper in PubMed, 13 citations in OpenAlex.
- Understanding the time course of pharmacological effect: a PKPD approach.British journal of clinical pharmacology · 2011Review
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
2 authors at 1 institution in 1 country.
Funding
No grant is acknowledged in the PubMed record.
Abstract
what is already known about this subjectThe clearance of many drugs is reduced in the elderly, but the data regarding phenytoin are conflicting. Most studies have estimated phenytoin metabolic clearance using total drug concentrations (bound plus unbound), which may be confounded by protein binding effects. Free phenytoin concentrations are independent of protein binding and should more accurately reflect true metabolic clearance changes in elderly patients. WHAT THIS STUDY ADDS: The two studies reported in this paper suggest a trend towards reduced free phenytoin 'apparent clearance' in the elderly, although statistically significant results were not found. Other published studies have largely found similar trends, suggesting an age effect.
aimsTo test the hypothesis that the 'apparent clearance' of free phenytoin is reduced in elderly patients.
methodsTwo separate studies were conducted comparing free phenytoin 'apparent clearance' in elderly vs. younger adults. The first study was a retrospective analysis of free phenytoin concentrations measured at Christchurch Hospital from 1997 to 2006. In the second study free phenytoin concentrations were measured prospectively in ambulatory subjects who were taking phenytoin regularly.
resultsIn the retrospective study (n= 29), free phenytoin 'apparent clearance' was 0.27 +/- 0.04 l kg(-1) day(-1) (95% CI 0.19, 0.34) in the elderly cohort vs. 0.37 +/- 0.06 l kg(-1) day(-1) (95% CI 0.22, 0.52) in younger adults, but the difference was not statistically significant. In the prospective study, free phenytoin 'apparent clearance' showed a non-significant trend to being reduced in the elderly patients (0.12 +/- 0.02 l kg(-1) day(-1), 95% CI 0.07, 0.17) compared with the younger cohort (0.18 +/- 0.07 l kg(-1) day(-1), 95% CI 0.09, 0.26) in those not taking interacting drugs (n= 21).
conclusionsThis research does not prove the hypothesis that the 'apparent clearance' of free phenytoin is reduced in the elderly. However, the trends found in these two studies are supported by trends in the same direction in other published studies, suggesting an age effect.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
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.