Impact of changing from cyclosporine to tacrolimus on pharmacokinetics of mycophenolic acid in renal transplant recipients with diabetes

Preparation and application of foamed ceramic panels in interior design

A new type of foam ceramics was prepared with fly ash (CFA). Before sintering, the CFA underwent alkali activation, resulting in an even layer of hydroxy sodalite crystals covering the CFA particles. The pre-treatment of the CFA-alkali-activated material caused it to exhibit a reaction in sintering. The foamed ceramics had the best qualities when sintered at 1,300°C; the leaching toxicity studies of a material used in interior design revealed that during sintering.

Association of ABCC2 Haplotypes to Mycophenolic Acid Pharmacokinetics in Stable Kidney Transplant Recipients

Mycophenolic acid exhibits significant interpatient pharmacokinetic variability attributed to factors including race, sex, concurrent medications, and enterohepatic circulation of the mycophenolic acid glucuronide metabolite to mycophenolic acid. This conversion by enterohepatic circulation is mediated by the multidrug resistance-associated protein 2, encoded by ABCC2. This study investigated ABCC2 haplotype associations with mycophenolic acid pharmacokinetics in 147 stable kidney transplant recipients receiving mycophenolic acid in combination with calcineurin inhibitors. The role of the ABCC2 genotypes -24C>T (rs717620), 1249C>T (rs2273697), and 3972C>T (rs3740066) were evaluated in prospective, cross-sectional pharmacokinetic studies of stable recipients receiving mycophenolic acid and either tacrolimus or cyclosporine. Haplotype phenotypic associations with mycophenolic acid pharmacokinetic parameters were computed using THESIAS (v. 3.1). Four ABCC2 haplotypes with estimated frequencies greater than 10% were identified (H1:CGC [wild type], H9:CGT, H2:CAC, H12:TGT). There were no differences in haplotype frequencies by either race or sex. There were significant associations of pharmacokinetic parameters with ABCC2 haplotypes for mycophenolic acid clearance (L/h), mycophenolic acid AUC_0-12h (mg·h/L), and the ratio of mycophenolic acid glucuronide to mycophenolic acid AUC_0-12h . The wild-type haplotype ABCC2 CGC had greater mycophenolic acid AUC_0-12h (P = .017), slower clearance (P = .013), and lower mycophenolic acid glucuronide to mycophenolic acid AUC_0-12h ratio (P = .047) compared with the reduced function ABCC2 haplotype CGT. These differences were most pronounced among patients receiving tacrolimus cotreatment. No phenotypic associations were found with the cyclosporine-mycophenolic acid regimen. Variation in ABCC2 haplotypes contributes to subtherapeutic mycophenolic acid exposure and influences interpatient variability in pharmacokinetic phenotypes based on concurrent calcineurin inhibitor treatment.

Influence of Calcineurin Inhibitor and Sex on Mycophenolic Acid Pharmacokinetics and Adverse Effects Post-Renal Transplant

Tacrolimus or cyclosporine is prescribed with mycophenolic acid posttransplant and contributes to interpatient variability in mycophenolic acid pharmacokinetics and response. Cyclosporine inhibits enterohepatic circulation of the metabolite mycophenolic acid glucuronide, which is not described with tacrolimus. This study investigated mycophenolic acid pharmacokinetics and adverse effects in stable renal transplant recipients and the association with calcineurin inhibitors, sex, and race. Mycophenolic acid and mycophenolic acid glucuronide area under the concentration-time curve from 0 to 12 hours (AUC_0-12h ) and apparent clearance were determined at steady state in 80 patients receiving cyclosporine with mycophenolate mofetil and 67 patients receiving tacrolimus with mycophenolate sodium. Gastrointestinal adverse effects and hematologic parameters were evaluated. Statistical models evaluated mycophenolic acid pharmacokinetics and adverse effects. Mycophenolic acid AUC_0-12h was 1.70-fold greater with tacrolimus (68.9 ± 30.9 mg·h/L) relative to cyclosporine (40.8 ± 17.6 mg·h/L); P < .001. Target mycophenolic acid AUC_0-12h of 30-60 mg·h/L was achieved in 56.3% on cyclosporine compared with 34.3% receiving tacrolimus (P < .001). Mycophenolic acid clearance was 48% slower with tacrolimus (10.6 ± 4.7 L/h) relative to cyclosporine (20.5 ± 10.0 L/h); P < .001. Enterohepatic circulation occurred less frequently with cyclosporine (45%) compared with tacrolimus (78%); P < 0.001; with a 2.9-fold greater mycophenolic acid glucuronide AUC_0-12h to mycophenolic acid AUC_0-12h ratio (P < .001). Race did not affect mycophenolic acid pharmacokinetics. Gastrointestinal adverse effect scores were 2.2-fold higher with tacrolimus (P < .001) and more prominent in women (P = .017). Lymphopenia was more prevalent with tacrolimus (52.2%) than cyclosporine (22.5%); P < 0.001. Calcineurin inhibitors and sex contributed to interpatient variability in mycophenolic acid pharmacokinetics and adverse effects post-renal transplant, which could be attributed to differences in enterohepatic circulation.

Clinical guideline: management of gastroparesis

This guideline presents recommendations for the evaluation and management of patients with gastroparesis. Gastroparesis is identified in clinical practice through the recognition of the clinical symptoms and documentation of delayed gastric emptying. Symptoms from gastroparesis include nausea, vomiting, early satiety, postprandial fullness, bloating, and upper abdominal pain. Management of gastroparesis should include assessment and correction of nutritional state, relief of symptoms, improvement of gastric emptying and, in diabetics, glycemic control. Patient nutritional state should be managed by oral dietary modifications. If oral intake is not adequate, then enteral nutrition via jejunostomy tube needs to be considered. Parenteral nutrition is rarely required when hydration and nutritional state cannot be maintained. Medical treatment entails use of prokinetic and antiemetic therapies. Current approved treatment options, including metoclopramide and gastric electrical stimulation (GES, approved on a humanitarian device exemption), do not adequately address clinical need. Antiemetics have not been specifically tested in gastroparesis, but they may relieve nausea and vomiting. Other medications aimed at symptom relief include unapproved medications or off-label indications, and include domperidone, erythromycin (primarily over a short term), and centrally acting antidepressants used as symptom modulators. GES may relieve symptoms, including weekly vomiting frequency, and the need for nutritional supplementation, based on open-label studies. Second-line approaches include venting gastrostomy or feeding jejunostomy; intrapyloric botulinum toxin injection was not effective in randomized controlled trials. Most of these treatments are based on open-label treatment trials and small numbers. Partial gastrectomy and pyloroplasty should be used rarely, only in carefully selected patients. Attention should be given to the development of new effective therapies for symptomatic control.

Association of mycophenolic acid dose with efficacy and safety events in kidney transplant patients receiving tacrolimus: an analysis of the Mycophenolic acid Observational REnal transplant registry

Background Dose-finding studies for mycophenolic acid (MPA) in tacrolimus-treated kidney transplant patients are lacking.

Methods Data from 901 de novo kidney transplant recipients enrolled in the prospective, non-interventional Mycophenolic acid Observational REnal (MORE) transplant registry were analyzed according to baseline daily MPA dose (<2000, 2000 or >2000 mg).

Results The proportion of patients receiving 2000 and <2000 mg was 77.6% and 19.9% at baseline, 74.5% and 23.3% at month 1, 62.4% and 35.5% at month 3, 48.5% and 50.2% at month 6, and 44.1% and 55.2% at month 12. More patients were maintained on 2000 mg with enteric-coated mycophenolate sodium (EC-MPS) vs. mycophenolate mofetil (month 6, 52.7% vs. 43.0% [p = 0.02]; month 12, 47.3% vs. 39.4% [p = 0.08]). Multivariate modeling showed no significant effect of baseline MPA dose on 12-month risk of biopsy-proven acute rejection, graft loss or estimated GFR, or on safety events including MPA discontinuation other than a higher rate of gastrointestinal adverse events in patients with an initial MPA dose >2000 mg (p = 0.029) vs. 2000 mg.

Conclusions These findings suggest that an initial MPA dose of <2000 mg does not compromise 12-month efficacy in tacrolimus-treated kidney transplants, but controlled trials are required and the lower threshold for MPA dose remains to be defined.

What are the important subsets of gastroparesis?

Gastroparesis is often divided into subsets based on etiology and pathophysiology; however, the utility of these subsets in the diagnosis and treatment of gastro-paresis is not well defined. The objectives are to consider the subsets of gastroparesis from the perspectives of etiology and pathogenesis, pathophysiology, histopathology, and clinical associations, with particular focus on similarities and differences between diabetic and idiopathic gastroparesis and consideration of the potential subset of painful gastroparesis. We conclude that idiopathic and diabetic gastroparesis has similar initial presentations and manifestations, except that idiopathic gastroparesis tends to be associated more frequently with pain. Myopathic disorders are uncommon. Extrinsic denervation was considered the most common etiology; however, with the decline in surgery for peptic ulceration and in-depth study of full-thickness gastric biopsies, the most common intrinsic defects are being recognized in the interstitial cells of Cajal (ICC-opathy) and with immune infiltration and neuronal changes (intrinsic neuropathic gastroparesis). Histomorphological differences at the microscopic level between diabetic and idiopathic gastroparesis are still of unclear significance. Two gastroparesis subsets worthy of special mention, because they are potentially reversible with identification of the cause, are postviral gastroparesis, which has a generally good prognosis, and iatrogenic gastroparesis, especially in patients with non-surgical gastroparesis, such as diabetics exposed to incretins such as pramlintide and exenatide.

A review on therapeutic drug monitoring of immunosuppressant drugs

: Immunosuppressants require therapeutic drug monitoring because of their narrow therapeutic index and significant inter-individual variability in blood concentrations. This variability can be because of factors like drug-nutrient interactions, drug-disease interactions, renal-insufficiency, inflammation and infection, gender, age, polymorphism and liver mass. Drug monitoring is widely practiced especially for cyclosporine, tacrolimus, sirolimus and mycophenolic acid. CYCLOSPORINE: Therapeutic monitoring of immunosuppressive therapy with cyclosporine is a critical requirement because of intra- and inter-patient variability of drug absorption, narrow therapeutic window and drug induced nephrotoxicity. MYCOPHENOLIC ACID MPA: Some reasons for therapeutic drug monitoring of MPA during post-transplant period include: relationship between MPA pharmacokinetic parameters and clinical outcomes, Inter-patient pharmacokinetic variability for MPA despite fixed MMF doses, alternations of MPA pharmacokinetics during the first months after transplantation, drug- drug interaction and influence of kidney function on MPA pharmacokinetic. SIROLIMUS: A recent review of the pharmacokinetics of sirolimus suggested a therapeutic range of 5 to 10 μg l(-1) in whole blood. However, the only consensus guidelines published on the therapeutic monitoring of sirolimus concluded that there was not enough information available about the clinical use of the drug to make recommendations. TACROLIMUS: Sudies have shown, in kidney and liver transplant patients, significant associations of low tacrolimus concentrations with rejection and of high concentrations with nephrotoxicity. Although the feasibility of a limited sampling scheme to predict AUC has been demonstrated, as yet, trough, or pre-dose, whole blood concentration monitoring is still the method of choice.