Dried blood spot sampling of nilotinib in patients with chronic myeloid leukaemia: a comparison with venous blood sampling.

OBJECTIVES: To compare nilotinib concentrations obtained by venous blood sampling and dried blood spot (DBS) in patients with chronic myeloid leukaemia (CML). It was investigated how to predict nilotinib plasma levels on the basis of DBS. METHODS: Forty duplicate DBS and venous blood samples were collected from 20 patients. Capillary blood was obtained by finger prick and spotted on DMPK-C Whatman sampling paper, simultaneously with venous blood sampling. Plasma concentrations were predicted from DBS concentrations using three methods: (1) individual and (2) mean haematocrit correction and (3) the bias between plasma and DBS concentrations. Results were compared using Deming regression and Bland-Altman analysis. KEY FINDINGS: Nilotinib plasma concentrations ranged from 376 to 2663 µg/l. DBS concentrations ranged from 144 to 1518 µg/l. The slope was 0.56 (95% CI, 0.51 to 0.61) with an intercept of -41.68 µg/l (95% CI, -93.78 to 10.42). Mean differences between calculated and measured plasma concentrations were -14.3% (method 1), -14.0% (method 2) and -0.6% (method 3); differences were within 20% of the mean in 73%, 85% and 80% of the samples, respectively. The slopes were respectively 0.96 (95% CI, 0.86 to 1.06), 0.95 (95% CI, 0.86 to 1.03) and 1.00 (95% CI, 0.91 to 1.09). CONCLUSIONS: Plasma concentrations of nilotinib could be predicted on the basis of DBS. DBS sampling to assess nilotinib concentrations in CML patients seems a suitable alternative for venous sampling.

The impact of type of manual medication cart filling method on the frequency of medication administration errors: a prospective before and after study.

BACKGROUND: The medication cart can be filled using an automated system or a manual method and when using a manual method the medication can be arranged either by round time or by medication name. For the manual methods, it is hypothesized that the latter method would result in a lower frequency of medication administration errors because nurses are forced to read the medication labels, but evidence for this hypothesis is lacking. OBJECTIVES: The aim of this study was to compare the frequency of medication administration errors of two different manual medication cart filling methods, namely arranging medication by round time or by medication name. DESIGN: A prospective, observational study with a before-after design. PARTICIPANTS AND SETTINGS: Eighty-six patients who stayed on an orthopaedic ward in one university medical centre in the Netherlands were included. METHODS: Disguised observation was used to detect medication administration errors. The medication cart filling method in usual care was to fill the cart with medication arranged by round time. The intervention was the implementation of the second medication cart filling method, where the medication cart was filled by arranging medicines by their names. The primary outcome was the frequency of medication administrations with one or more error(s) after the intervention compared with before the intervention. The secondary outcome was the frequency of subtypes of medication administration errors. RESULTS: After the intervention 170 of 740 (23.0%) medication administrations with one or more medication administration error(s) were observed compared to 114 of 589 (19.4%) before the intervention (odds ratio 1.24 [95% confidence interval 0.95-1.62]). The distribution of subtypes of medication administration errors before and after the intervention was statistically significantly different (p<0.001). Analysis of subtypes revealed more omissions and wrong time errors after the intervention than before the intervention. Unauthorized medication errors were detected more frequently before the intervention than after the intervention. CONCLUSION: The frequency of medication administration errors with the medication cart filling method where the medication is arranged by name was not statistically significantly different compared to the medication cart filling method where the medication is arranged by round time.