Myelofibrosis (MF), polycythemia vera (PV) and essential thrombocythemia (ET) are three classic BCR ABL fusion gene-negative chronic myeloproliferative neoplasms (MPNs). Though rare, it is important to understand the burden of illness of these disorders for public health planning, healthcare insurers and pharmaceutical manufacturers. Therefore, we have described the incidence of MF and prevalence of MF, ET and PV in the United States between 2008 and 2010 based on data from two large health plans. The incidence of primary MF was about 1 per 100 000 per year and did not vary over the study years. The prevalence of PV (44-57 per 100 000) and ET (38-57 per 100 000) was much higher than that of MF (4-6 per 100 000) or subgroups containing MF (post-PV MF = 0.3-0.7 per 100 000; post-ET MF = 0.5-1.1 per 100 000). Additional research using other national databases and/or study designs is needed to substantiate these findings.

Poor medication adherence is associated with a significantly increased risk of fracture versus optimal adherence. Improving medication adherence in patients with osteoporosis may lead to a greater reduction in fracture.

No abstract

Respiratory depression is common in patients recovering from surgery and anaesthesia. Failure to recognise and lack of timely institution of intervention can lead to catastrophic cardiorespiratory arrest, anoxic brain injury, and mortality. Opioid-induced respiratory depression (OIRD) is a common and often under-diagnosed cause of postoperative respiratory depression. Other causes include residual anaesthesia, residual muscle paralysis, concurrent use of other sedatives, splinting from inadequate pain control, and obstructive sleep apnoea. Currently used methods to identify and monitor respiratory safety events in the post-surgical setting have serious limitations leading to lack of universal adoption. New tools and technologies currently under development are expected to improve the prediction of respiratory depression especially in patients requiring opioids to alleviate acute postoperative pain. In this narrative review, we discuss the various causes of postoperative respiratory depression, and highlight the advances in monitoring and early recognition of patients who develop this condition with an emphasis on OIRD.

No abstract

Small interfering RNAs (siRNAs) represent a new class of medicines that are smaller (∼16,000 Da) than biologic therapeutics (>150,000 Da) but much larger than small molecules (<900 Da). Current regulatory guidance on drug-drug interactions (DDIs) from the European Medicines Agency, Food and Drug Administration, and Pharmaceutical and Medical Devices Agency provides no recommendations for oligonucleotide therapeutics including siRNAs; therefore, small molecule guidance documents have historically been applied. Over ∼10 years, in vitro DDI investigations with siRNAs conjugated to a triantennary N-acetylgalactosamine [(GalNAc)-siRNA] ligand have been conducted during nonclinical drug development to elucidate the potential clinical DDI liability. GalNAc siRNAs were evaluated as substrates, inhibitors, or inducers of major cytochrome P450s (P450s) and as substrates and inhibitors of transporters. Aggregate analysis of these data demonstrates a low potential for DDI against P450s. Zero of five, 10, and seven are inducers, time-dependent inhibitors, or substrates, respectively, and nine of 12 do not inhibit any P450 isoform evaluated. Three GalNAc siRNAs inhibited CYP2C8 at supratherapeutic concentrations, and one mildly inhibited CYP2B6. The lowest K i value of 28 mM is >3000-fold above the therapeutic clinical C max at steady state, and importantly no clinical inhibition was projected. Of four GalNAc siRNAs tested none were substrates for transporters and one caused inhibition of P-glycoprotein, calculated not to be clinically relevant. The pharmacological basis for DDIs, including consideration of the target and/or off-target profiles for GalNAc siRNAs, should be made as part of the overall DDI risk assessment. If modulation of the target protein does not interfere with P450s or transporters, then in vitro or clinical investigations into the DDI potential of the GalNAc siRNAs are not warranted. SIGNIFICANCE STATEMENT Recommendations for evaluating DDI potential of small molecule drugs are well established; however, guidance for novel modalities, particularly oligonucleotide-based therapeutics are lacking. Given the paucity of published data in this field, in vitro DDI investigations are often conducted. The aggregate analysis of GalNAc-siRNA data reviewed herein demonstrates that, like new biological entities, these oligonucleotide-based therapeutic drugs are unlikely to result in DDIs; therefore, it is recommended that the need for in vitro or clinical investigations similarly be determined on a case-by-case basis. Given the mechanism of siRNA action, special consideration should be made in cases where there may be a pharmacological basis for DDIs.

Despite limitations of this study, including conventional generalizability issues, and sensitivity and specificity of claims-based diagnoses, results are consistent with other research and provide compelling results of substantial cost burden of fractures related to osteoporosis. Low rates of osteoporosis diagnosis and treatment among patients with costly fragility fractures underscore the opportunity for managed care organizations to initiate comprehensive disease management programs in osteoporosis.

Physicians overestimate patient adherence to PMO therapies. Improving physician awareness of medication non-adherence to PMO therapies may facilitate physician-patient dialogue, with the aim of identifying patient-centered reasons for non-adherence. These discussions are important because patients with poorer adherence have a higher risk of fracture. Future research should focus on reasons for patient non-adherence to osteoporosis regimens and intervention strategies that improve communication between the provider and patient. Findings must be considered within the limitations of this claims database analysis. Some degree of incomplete or incorrect coding may exist, and the presence of a claim for a filled prescription does not indicate that the medication was consumed or taken as prescribed. Patients included in the study are not necessarily representative of all patients being treated for osteoporosis.