Impact of pharmacist counseling to enhance the accessibility of naloxone nasal spray to patients in a community pharmacy setting.

Background: The Centers for Disease Control and Prevention guidelines recommend naloxone for every high-dose opioid prescription; in 2018, only 1 naloxone prescription was dispensed for every 69 high-dose opioid prescriptions. In Virginia, strategies for creating awareness and availability include the REVIVE! training and the standing protocol for pharmacists to dispense naloxone.

Objectives: To evaluate if a proactive offer for counseling by pharmacists improves the percent change of patients who receive a prescription for naloxone nasal spray compared with the previous year's naloxone nasal spray fill history and to determine if the pharmacist's counseling affects a patient's confidence with opioid overdose and naloxone use.

Multi-center evaluation of a commercial Kit for tacrolimus determination by LC/MS/MS.

Objectives: A multi-center evaluation (3 sites) of the LC/MS/MS MassTrak tacrolimus Immunosuppressants Kit (Kit) was undertaken.

Design And Methods: Ten aspects of the analytical performance of the Kit were investigated based on FDA and CLSI guidelines.

Results: The linear analytical range of the procedure was between 0.

12-hour area under the curve cyclosporine concentrations determined by a validated liquid chromatography-mass spectrometry procedure compared with fluorescence polarization immunoassay reveals sirolimus effect on cyclosporine pharmacokinetics.

Liquid chromatographic (LC) procedures have been applied to cyclosporine therapeutic drug monitoring (TDM) since the agent was introduced in 1983. In recent years, the advance to mass spectrometric (MS) detection has enhanced the capability of LC by providing more sensitive and selective detection, a wider analytical range, faster turnaround time, and relative ease of use. Although fluorescence polarization immunoassay (FPIA) is a widely popular technology for cyclosporine TDM, it is compromised by a limited analytical range and lack of selectivity for parent drug.

Is microparticle enzyme-linked immunoassay (MEIA) reliable for use in tacrolimus TDM? Comparison of MEIA to liquid chromatography with mass spectrometric detection using longitudinal trough samples from transplant recipients.

In the larger transplant centers where technical expertise is available, liquid chromatography with mass spectrometric detection (LC-MS) for tacrolimus therapeutic drug monitoring is replacing the popular microparticle enzyme-linked immunoassay (MEIA) as a cost-effective alternative technology. As more labs convert to LC-MS, the accuracy, precision, selectivity, and sensitivity of the tacrolimus MEIA are being challenged, using data from large populations of clinical samples. However, little attention has been paid to how the results of particular procedures may differ within and among individual patients and to how such differences may relate to patients' characteristics or to relevant biochemical parameters.

Validation of a practical liquid chomatography with ultraviolet detection method for quantification of whole-blood everolimus in a clinical TDM laboratory.

Until now, only LC/MS methods for quantification of everolimus have been published. The authors validated an LC/UV method for quantification of everolimus from whole blood. The authors sought to improve on the protocol for sirolimus determination previously reported by French et al.

Analytic aspects of cyclosporine monitoring, on behalf of the IFCC/IATDMCT Joint Working Group.

The use of therapeutic drug monitoring strategies for cyclosporin (CsA) has evolved markedly in recent years since previous consensus guidelines were presented. Apart from the introduction of some new methods, the major change has been the shift away from the traditional predose/trough (C0) sample. The most popular alternative has been shown to be a 2-hour postdose (C2) sample.

International Federation of Clinical Chemistry/International Association of Therapeutic Drug Monitoring and Clinical Toxicology working group on immunosuppressive drug monitoring.

Issues surrounding the measurement and interpretation of immunosuppressive drug concentrations have been summarized in a number of consensus documents. The Scientific Division of the International Federation of Clinical Chemistry has formed a working group in collaboration with the International Association of Therapeutic Drug Monitoring and Clinical Toxicology. This paper sets out the goals of the working group in light of the developments that have occurred in the field of immunosuppressive drug monitoring since the publication of the last consensus documents.

The development of sirolimus: The University of Texas-Houston experience.

The transplant team at The University of Texas-Houston has studied sirolimus from preclinical through pivotal Phase III trials to single-center Phase IV trials as we continue to refine algorithms for sirolimus therapy. The sirolimus/CsA combination produces a marked reduction in the occurrence and severity of acute allograft rejection episodes. A recently completed post hoc median effect analysis of drug blood concentrations displayed by patients in the 2 pivotal Phase III trials documented that the combination displays synergistic interactions.

Simultaneous simple and fast quantification of three major immunosuppressants by liquid chromatography--tandem mass-spectrometry.

Objectives: The aim of the current study was to develop a simple, fast and universal method for quantification of any combination of the three major immunosuppressants sirolimus, tacrolimus and cyclosporin in whole blood, using a LC-tandem mass spectrometer (API-2000, SCIEX, Toronto, Canada).

Methods: 250 microL whole blood was spiked with internal standard (ritonavir), and protein precipitated with 350 microL acetonitrile. The sample was centrifuged and 30 microL aliquot was injected onto the HPLC column, where it underwent an online extraction with ammonium acetate.

Effect of low dose cyclosporine and sirolimus on hepatic drug metabolism in the rat1.

Background: We examined the effect cyclosporine (CsA) and sirolimus (SRL) alone and in combination on hepatic cytochrome P450-mediated metabolism in rats.

Methods: Rats were given 1 mg/kg of CsA or 0.4 mg/kg of SRL alone or in combination via constant intravenous infusion.

Pharmacokinetic interactions augment toxicities of sirolimus/cyclosporine combinations.

This study correlated the dynamic effects of sirolimus (rapamycin; RAPA) and cyclosporine (CsA) alone versus in combination to produce renal dysfunction, myelosuppression, or hyperlipidemia, with their corresponding blood and tissue concentrations. After salt-depleted rats were treated with RAPA (0.4 to 6.

Cytochrome P450 3A9 catalyzes the metabolism of progesterone and other steroid hormones.

The catalytic requirements and the role of P450 3A9, a female-specific isoform of CYP3A from rat brain, in the metabolism of several steroid hormones were studied using recombinant P450 3A9 protein. The optimal steroid hormone hydroxylase activities of P450 3A9 required cholate but not cytochrome b5. P450 3A9 was active in the hydroxylation reactions of testosterone, androstenedione, progesterone and dehydroepiandrosterone (DHEA).

Metabolism of cyclosporine by cytochromes P450 3A9 and 3A4.

The ability of P450 3A9 to transform cyclosporine was studied and compared to that of human P450 3A4. Purified P450 3A4 and P450 3A9 proteins were reconstituted in a system containing potassium phosphate buffer, lipids, NADPH-P450 reductase, and glutathione with NADPH added to initiate the reaction. Cyclosporine was added alone and with or without the inhibitors, ketoconazole or troleandomycin.

A practical guide to the analysis of sirolimus using high-performance liquid chromatography with ultraviolet detection.

Background: Sirolimus, a new immunosuppressive agent, has recently been approved in the United States for use in combination with cyclosporine and corticosteroids in renal allograft transplantation. Therapeutic drug monitoring (TDM) of sirolimus is advocated by the drug's manufacturer in certain patient populations. Given the known pharmacokinetic interaction of sirolimus with cyclosporine and the requirement for patient compliance, physicians may wish to monitor steady-state trough levels of this agent.

Therapeutic drug monitoring of sirolimus: correlations with efficacy and toxicity.

Unlabelled: We sought to examine the potential benefits of therapeutic drug monitoring of sirolimus, a potent immunosuppressive agent that displays a pleiotropic array of side effects.

Methods: A high-performance liquid chromatography (LC) procedure combined with ultraviolet detection (UV) was used to measure serial concentrations of parent compound sirolimus in 150 renal transplant recipients over a period of 4 yr. Drug concentrations in whole blood at trough time, as well as within pharmacokinetic profiles, were correlated with clinical events using contingency tables, logistic regression analysis, and receiver operating characteristic (ROC) curves.

Comparison of steady-state trough sirolimus samples by HPLC and a radioreceptor assay.

Objectives: We have previously identified a minor immunophilin of 52 kDa molecular weight capable of binding tacrolimus and sirolimus. Because immunophilins are capable of binding both parent drug and metabolites and HPLC assays are typically used to assess parent drug in clinical situations, we used this immunophilin in a radioreceptor assay (RRA) to determine if any metabolites not included in the HPLC measurement would bind to the immunophilin and be associated with thrombocytopenia in patients receiving sirolimus.

Design And Methods: We tested 51 steady-state trough whole blood samples from non-thrombocytopenic patients and 51 steady-state trough samples from thrombocytopenic patients and compared them to HPLC measurements of parent drug in the same samples.

The FTY720 story.

The chemical 2-amino-2[2-(4-octylphenyl)ethyl]-1,3,propane diol is one of a class of small-molecule immunosuppressive agents. Better known as FTY720, this compound was chemically synthesized in an effort to minimize the toxic in vivo properties of a structurally related and highly potent immunosuppressive agent, myriocin. FTY720's mechanism of action, although not fully characterized, appears to be unique among immunosuppressants.

Conversion from liquid to solid rapamycin formulations in stable renal allograft transplant recipients.

Sirolimus (rapamycin, RAPA, Rapamunetrade mark) is a potent immunosuppressive agent currently being investigated for prophylaxis against acute rejection episodes in renal transplant recipients. In the present study, stable renal allograft recipients under maintenance therapy with RAPA and cyclosporine (CsA) were converted from the original oil-based liquid RAPA to a solid tablet formulation on a milligram-to-milligram basis, in order to evaluate the pharmacokinetics and safety of this new dosage form. Twelve-hour pharmacokinetic (PK) profiles of both RAPA and CsA were conducted with the final liquid RAPA dose, and at 2, 4, and 8 weeks postconversion to the solid tablet.

Correlation between pretransplantation test dose cyclosporine pharmacokinetic profiles and posttransplantation sirolimus blood levels in renal transplant recipients.

We sought to determine whether pretransplantation test dose pharmacokinetic measurements of cyclosporine (CsA) concentrations would forecast the posttransplantation blood concentrations of sirolimus in renal transplant patients treated de novo with CsA, sirolimus, and prednisone. All 44 renal transplant recipients enrolled in Phase I/II studies of de novo posttransplantation therapy with sirolimus, CsA, and prednisone underwent pretransplantation pharmacokinetic profiling after having received paired intravenous (i.v.