Prescribing Errors With Low-Molecular-Weight Heparins

BACKGROUND

Low-molecular-weight heparins (LMWHs) are used in the prevention and treatment of venous thromboembolism (VTE). Bleeding is the primary major complication of LMWH therapy, which is associated with dose. The administration of appropriate dosages of LMWHs depends on the patient's risk of VTE, risk of bleeding, bodyweight, and renal function. Therefore, LMWH prescribing is prone to errors. However, no earlier study has explored the frequency of prescribing errors with LMWH.

PURPOSE

The aim of the study was to determine the frequency and determinants of in-hospital LMWH-prescribing errors.

METHODS

A cross-sectional study was conducted to examine the frequency and determinants of LMWH prescribing errors between April and August 2014. We randomly selected 500 patients 18 years and older with at least one LMWH prescription during inpatient hospitalization. A prescribing error was a deviation from the internal hospital guidelines. Logistic regression estimated determinants of prescribing error.

RESULTS

A prescribing error was present with 34% of all LMWH users. The most frequently recorded error was a dose that was not adjusted to body weight and/or renal function (85%). Prophylactic LMWH prescribing in medical wards was associated with a higher risk of prescribing error as compared with surgical wards.

CONCLUSIONS

The frequency of prescribing errors was 34% in a tertiary care hospital. Being a patient with prophylactic LMWH use on a medical ward is a determinant for LMWH prescribing error. Interventions that will lead to better electronic recording of body weight and more awareness among medical doctors may reduce the total number of prescribing errors.

The Influence of Prostaglandin E1 and Use of Inhibitor Percentage on the Correlation between the Multiplate and VerifyNow in Patients on Dual Antiplatelet Therapy

Platelet function tests (PFT), such as the Multiple Electrode Analyzer (Multiplate) and VerifyNow, show little concordance in patients using antiplatelet drugs. A major difference between these tests is the use of prostaglandin E1 (PGE1) to inhibit P2Y1-platelet-receptor activation in VerifyNow and is proposed to be of influence in the discrepancy between these tests. We aimed to investigate whether the presence of PGE1 could provide an explanation for the moderate correlation and concordance between Multiplate and VerifyNow by adding PGE1 to the Multiplate ADP assay, also known as the ADP-high sensitivity (ADP-HS) assay. We also aimed to investigate whether the difference in baseline platelet function as measured by the VerifyNow and Multiplate could (partly) explain the moderate correlation between the tests, by plotting ADP assay results against baseline function as measured by the corresponding device, which is expressed as the 'inhibitor percentage.' Fifty-one patients who underwent percutaneous coronary intervention (PCI) received dual antiplatelet therapy and were considered to have a high risk of ischemic or bleeding complications were included. The addition of 20 µl PGE1 in the Multiplate resulted in a significant reduction in Arbitrary Aggregation Units, but did not improve correlation with the VerifyNow. The correlation between VerifyNow and Multiplate inhibitor percentage was moderate. Based on these results, we concluded that neither PGE1 nor the calculation of the inhibitor percentage greatly influenced the correlation between PFTs.

Insulin-like growth factor (IGF) I down-regulates type 1 IGF receptor (IGF 1R) and reduces the IGF I response in A549 non-small-cell lung cancer and Saos-2/B-10 osteoblastic osteosarcoma cells

The insulin-like growth factor type 1 receptor (IGF 1R) mediates the acute metabolic effects of IGF I as well as IGF I-stimulated cell proliferation and protection from apoptosis. IGF binding proteins (IGFBPs) can modulate these responses. We, therefore, investigated whether intrinsic IGFBPs interfere with IGF I-induced regulation of IGF 1R expression and with the biological response to IGF I in two human tumor cell lines, the non-small-cell lung cancer cell line A549 and the osteoblastic osteosarcoma cell line Saos-2/B-10. We compared the growth rates, IGFBP production, IGF I binding characteristics, IGF 1R protein and mRNA levels, and the acute IGF I response (stimulation of glycogen synthesis) after pretreatment of the cells in serum-free medium with or without added IGF I or medium supplemented with 5% fetal calf serum (FCS). In contrast to A549 cells, which produce IGF I and significant amounts of IGFBPs, survival and proliferation of Saos-2/B-10 cells, which do not produce IGF I or significant amounts of IGFBPs, depended on the addition of exogenous IGF I. IGF I increased the concentration of IGFBP-2 and -3 and decreased the concentration of IGFBP-4 in the medium of A549 cells. As compared to FCS, IGF I pretreatment in both cell lines decreased the number of specific IGF I binding sites, down-regulated total and membrane IGF 1R protein, and largely reduced or abolished the acute IGF I response without affecting IGF 1R mRNA levels. The data suggest that the IGF 1R protein of the two cell lines is translationally and/or posttranslationally down-regulated by its ligand in the presence and in the absence of locally produced IGFBPs and that the cell lines have retained this negative feedback to counteract IGF I stimulation.