Pharmacokinetics and pharmacodynamics of systemically administered glucocorticoids

Sequential therapy with cyclophosphamide and mycophenolic acid in patients with progressive immunoglobulin A nephropathy: a long-term follow-up

In progressive immunoglobulin (Ig)A nephropathy (IgAN), cyclophosphamide pulse therapy (CyP), high-dose intravenous immunoglobulins (IVIg) and mycophenolic acid (MPA) have been used to stop progressive loss of renal function, but disease progression may occur after the end of the initial treatment. Here, we report the long-term follow-up of patients with progressive IgAN with MPA as maintenance therapy after CyP (CyP-MPA). In a median observation time of 6·2 years, we analysed the slopes of the loss of renal function of 47 patients with biopsy-proven IgAN and treated with CyP. Thirty-one patients with further progression were treated with MPA maintenance for a median time of 5·2 years. Follow-up was compared with symptomatic therapy and IVIg as historically matched control groups. Median loss of renal function was reduced significantly from 0·9 ml/min to 0·1 ml/min per month with CyP (P < 0·05), and with MPA in patients with a relapse from -0·4 ml/min to -0·1 ml/min per month (P < 0·05) until the end of the study. Proteinuria decreased significantly from 1·6 g/l to 1·0 g/l after CyP, and during MPA treatment to 0·6 g/l (P = 0·001 Friedman test). Median renal survival time was in patients with CyP 10·5 years (range = 3·2-17·8), with CyP-MPA 10·7 years (range = 8·3-13·1), with IVIg 4·7 years (range = 2·6-6·6), and in untreated patients 1·2 years (range = 0·8-1·6; log-rank test P < 0·01). In patients with progressive IgAN, our long-term follow-up observation indicates that sequential CyP-MPA therapy maintains renal survival significantly.

The clinical use of corticosteroids in pregnancy

BACKGROUND

The use of antenatal steroid therapy is common in pregnancy. In early pregnancy, steroids may be used in women for the treatment of recurrent miscarriage or fetal abnormalities such as congenital adrenal hyperplasia. In mid-late pregnancy, the antenatal administration of corticosteroids to expectant mothers in anticipation of preterm birth is one of the most important advances in perinatal medicine; antenatal corticosteroids are now standard care for pregnancies at risk of premature delivery in high- and middle-income countries. The widespread uptake of this therapy is due to a compelling body of evidence demonstrating improved neonatal outcomes following antenatal corticosteroid exposure, stemming most notably from corticosteroid-driven maturation of fetal pulmonary function. As we approach the 50th anniversary of landmark work in this area by Liggins and Howie, it is apparent that much remains to be understood with regards to how we might best apply antenatal corticosteroid therapy to improve pregnancy outcomes at both early and mid to late gestation.

METHODS

Drawing on advances in laboratory science, pre-clinical and clinical studies, we performed a narrative review of the scientific literature to provide a timely update on the benefits, risks and uncertainties regarding antenatal corticosteroid use in pregnancy. Three, well-established therapeutic uses of antenatal steroids, namely recurrent miscarriage, congenital adrenal hyperplasia and preterm birth, were selected to frame the review.

RESULTS

Even the most well-established antenatal steroid therapies lack the comprehensive pharmacokinetic and dose-response data necessary to optimize dosing regimens. New insights into complex, tissue-specific corticosteroid signalling by genomic-dependent and independent mechanisms have not been used to inform corticosteroid treatment strategies. There is growing evidence that some fetal corticosteroid treatments are either ineffective, or may result in adverse outcomes, in addition to lasting epigenetic changes in a variety of homeostatic mechanisms. Nowhere is the need to better understand the intricacies of corticosteroid therapy better conveyed than in the findings of Althabe and colleagues who recently reported an increase in overall neonatal mortality and maternal morbidity in association with antenatal corticosteroid administration in low-resource settings.

CONCLUSIONS

New research to clarify the benefits and potential risks of antenatal corticosteroid therapy is urgently needed, especially with regard to corticosteroid use in low-resource environments. We conclude that there is both significant scope and an urgent need for further research-informed refinement to the use of antenatal corticosteroids in pregnancy.

Attenuation of TNF-α secretion by L-proline-based cyclic dipeptides produced by culture broth of Pseudomonas aeruginosa

To identify small molecule inhibitors of TNF-α, bioassay- and LC-MS-guided chemical investigation on EtOAc extract of Pseudomonas aeruginosa ABS-36 culture broth (EEPA) was performed, which yielded four proline-based cyclic dipeptides, cyclo(Gly-l-Pro) (1), cyclo(l-Pro-l-Phe) (2), cyclo(trans-4-hydroxy-l-Pro-l-Phe) (3) and cyclo(trans-4-hydroxy-l-Pro-l-Leu) (4). Compounds 1 and 3 exhibited potent inhibition of TNF-α release with IC50 values of 4.5 and 14.2μg/mL, respectively, while EEPA showed IC50 of 38.8μg/mL under lipopolysaccharide treated RAW 264.7 cell ELISA assay. Also, marked attenuation of mRNA-expression of TNF-α was shown by all compounds. In vivo testing in rats of EEPA and chemically synthesized 4 validated significant TNF-α reduction with 51% (500mg/kg) and 79% (50mg/kg), respectively. In addition, all compounds exhibited significant diminution of IL-1β and IL-6 mRNA-expression levels and NO production. All samples displayed only weak toxicity to lipopolysaccharide-induced RAW 264.7 cells.

Recurrent nocturnal hypoglycaemia as a cause of morning fatigue in treated Addison's disease--favourable response to dietary management: a case report

BACKGROUND

Addison's disease, or primary adrenal insufficiency, is often associated with reduced well-being and fatigue despite use of currently recommended adrenal hormone replacement. Hypoglycaemia is a known manifestation of glucocorticoid deficiency, but is generally considered rare in adults and not relevant to troubling ongoing symptoms in patients with Addison's disease.

CASE PRESENTATION

A 43 year old woman with a three year history of Addison's disease complained of severe morning fatigue and headaches, despite standard glucocorticoid replacement therapy in the form of thrice daily hydrocortisone and mineralocorticoid replacement with fludrocortisone. Alternative glucocorticoid replacement regimens and the addition of dehydroepiandrosterone replacement therapy had no effect. Nocturnal hypoglycaemia was suspected and a 4-day continuous glucose monitor system (CGMS) revealed hypoglycaemia (interstitial glucose < 2.2 mmol/L) between 0200-0400 h on 3 of 4 days. The patient was counselled to take an evening snack designed to ensure slow absorption of ingested carbohydrates. Nocturnal hypoglycaemia was then absent on follow up CGMS assessment. The patient noted a marked symptomatic improvement in morning symptoms, but with persistent fatigue during the day.

CONCLUSION

Currently, the best strategy for control of non-specific symptoms in treated Addison's disease is unknown, but it may be that investigation for hypoglycaemia and treatment, where necessary, could assist some sufferers to achieve improved wellbeing. A systematic study of this phenomenon in Addison's disease is required.

Drug target molecules to guide immunosuppression

The individual and interindividual variability of response to immunosuppressants combined with the prevailing concept of lifelong immunosuppression following any organ transplantation motivates the search for methods to further individualize such therapy. Traditional therapeutic drug monitoring, adapting dose according to concentrations in blood, targets the pharmacokinetic variability. It has been increasingly recognized, however, that there is also a considerable variability in the response to a given concentration. Attempts to overcome this variability in response include the efforts to identify relevant targets and methods for pharmacodynamic monitoring. For several of the currently used immunosuppressants there is experimental data suggesting markers that are relevant as indicators for individual monitoring of the effects of these drugs. There are also some clinical data to support these approaches; however what is generally missing, are studies that in a prospective manner demonstrates the benefits and effects on outcome. The monitoring of antithymocyte globulin by lymphocyte subset counts is actually the only well established example of pharmacodynamic monitoring. For drugs such as MPA and mTOR inhibitors, there are candidates such as IMPDH activity expression and p70SK6 phosphorylation status, respectively. The monitoring of CNIs using assays for NFAT RGE, either alone or combined with concentration measurements, is already well documented. Even here, some further investigations relating to the categories of organ transplant, combination of immunosuppressants etc. will be requested. Although some further standardization of the assay is warranted and there is a need for specific recommendations of target levels and how to adjust dose, the NFAT RGE approach to pharmacodynamic monitoring of CNIs may be close to implementation in clinical routine.

Pre-emptive 8 mg dexamethasone and 120 mg etoricoxib for pain prevention after periodontal surgery: A randomised controlled clinical trial

Several anti-inflammatory drugs have been used to reduce pain and discomfort after periodontal surgeries. This study evaluates the efficacy of using etoricoxib and dexamethasone for pain prevention after open-flap debridement surgery. In this study, 60 patients who were undergoing open flap debridment surgery were randomly assigned to receive a single dose preoperative medication 1 hour prior to surgery. The patients were divided into three groups. In Group 1, 20 patients were given placebo drug orally. In Group 2, 20 patients were given 8 mg Dexamethasone orally and in Group 3, 20 patients were given 120 mg Etoricoxib orally. Patients were instructed to complete a pain diary hourly for the first 8 hours after each surgery and three times a day on the following 3 days. The four point verbal rating scale (VRS 4) and Numerical rate scale were used to assess discomfort. Post-operative Assessment of Pain and Discomfort showed that persistent discomfort and pain were found to be more in the placebo group compared to dexamethasone and etoricoxib group. The adoption of a preemptive medication protocol using either etoricoxib or dexamethasone may be considered effective for pain and discomfort prevention after open-flap debridement surgeries.

Dexamethasone attenuates the embryotoxic effect of endometriotic peritoneal fluid in a murine model

PURPOSE

The in vitro fertilization (IVF) pregnancy rate of women with advanced stage endometriosis is nearly half that of the general population, suggesting incomplete targeting of the pathophysiology underlying endometriosis-associated infertility. Compelling evidence highlights inflammation as the etiologic link between endometriosis and infertility and a potential target for adjunctive treatment. The objective of this study was to examine the effect of dexamethasone on murine embryos exposed to human endometriotic peritoneal fluid (PF) using the established murine embryo assay model.

METHODS

PF was obtained from women with and without severe endometriosis. Murine embryos were harvested and randomly allocated to five groups of culture media conditions: (1) human tubal fluid (HTF), (2) HTF and 10 % PF from women without endometriosis, (3) HTF and 10 % PF from women with endometriosis (PF-E), (4) HTF with PF-E and 0.01 mcg/mL dexamethasone, and (5) HTF with PF-E and 0.1 mcg/mL dexamethasone. Embryos were cultured in standard conditions and evaluated for blastocyst development.

RESULTS

A total of 266 mouse embryos were cultured. Baseline blastulation rates were 63.6 %. The addition of peritoneal fluid from women with endometriosis decreased the blastocyst development rate to 38.9 % (P = 0.008). The addition of 0.1 mcg/mL of dexamethasone to the culture media restored the blastulation rate to near baseline levels (61.2 %; P = 0.019).

CONCLUSIONS

The results of our in vitro study demonstrate the capacity of dexamethasone to mitigate the deleterious impact of endometriotic PF on embryo development. If confirmed in vivo, dexamethasone may prove a useful adjunct for the treatment of endometriosis-associated infertility.

MORNING SERUM CORTISOL LEVEL AFTER TRANSSPHENOIDAL SURGERY FOR PITUITARY ADENOMA PREDICTS HYPOTHALAMIC-PITUITARY-ADRENAL FUNCTION DESPITE INTRAOPERATIVE DEXAMETHASONE USE

OBJECTIVE

Perioperative glucocorticoid (GC) is rarely needed in patients undergoing transsphenoidal surgery (TSS). We instituted a steroid-sparing protocol in the settings of intraoperative dexamethasone use. We evaluated the safety of using a cut off cortisol level of 14 μg/dL on postoperative day (POD)-1 and -6 after dexamethasone use during the surgery. We also analyzed the efficacy of serial morning cortisol levels for weaning GC replacement.

METHODS

The charts of 48 adult patients who received dexamethasone 4 mg intraoperatively were reviewed. Morning cortisol levels were measured on POD-1. Patients with cortisol ≥14 μg/dL were discharged without CG replacement. Morning cortisol level was checked routinely on POD-6, and GC replacement was initiated when the level was <14 μg/dL. Serial cortisol levels were measured in patients requiring GC after the first postoperative week.

RESULTS

Overall, 67% patients had POD-1 cortisol ≥14 μg/dL and did not require GC on discharge. After POD-6, 83% of patients were not on GC replacement. A cosyntropin stimulation testing (CST) was only performed in 3 patients. There were no hospital admissions for adrenal crisis during the postoperative period.

CONCLUSION

A steroid-sparing protocol with POD-1 and -6 morning cortisol levels can be safely and effectively used in the settings of intraoperative dexamethasone administration. It leads to avoidance of GC in more than two-thirds of patients on discharge and more than 80% of patients after the first postoperative week. We found that dynamic adrenal testing could be omitted in the majority of patients by using serial morning cortisol levels to assess the hypothalamic-pituitary-adrenal (HPA) axis.

Glucocorticoids as an emerging pharmacologic agent for cardiopulmonary resuscitation

Although cardiac arrest (CA) constitutes a major health problem with dismal prognosis, no specific drug therapy has been shown to improve survival to hospital discharge. CA causes adrenal insufficiency which is associated with poor outcome and increased mortality. Adrenal insufficiency may manifest as an inability to increase cortisol secretion during and after cardiopulmonary resuscitation (CPR). Several studies suggest that glucocorticoids during and after CPR seem to confer benefits with respect to return of spontaneous circulation (ROSC) rates and long term survival. They have beneficial hemodynamic effects that may favor their use during CPR and in the early post-resuscitation period. Moreover, they have anti-inflammatory and anti-apoptotic properties that improve organ function by reducing ischemia/reperfusion (I/R) injury. However, glucocorticoid supplementation has shown conflicting results with regard to survival to hospital discharge and neurological outcome. The purpose of this article is to review the pathophysiology of hypothalamic-pituitary-adrenal (HPA) axis during CPR. Furthermore, this article reviews the effects of glucocorticoids use during CRP and the post-resuscitation phase.

Current and novel approaches to children and young people with congenital adrenal hyperplasia and adrenal insufficiency

Congenital adrenal hyperplasia (CAH) represents a group of autosomal recessive conditions leading to glucocorticoid deficiency. CAH is the most common cause of adrenal insufficiency (AI) in the paediatric population. The majority of the other forms of primary and secondary adrenal insufficiency are rare conditions. It is critical to establish the underlying aetiology of each specific condition as a wide range of additional health problems specific to the underlying disorder can be found. Following the introduction of life-saving glucocorticoid replacement sixty years ago, steroid hormone replacement regimes have been refined leading to significant reductions in glucocorticoid doses over the last two decades. These adjustments are made with the aim both of improving the current management of children and young persons and of reducing future health problems in adult life. However despite optimisation of existing glucocorticoid replacement regimens fail to mimic the physiologic circadian rhythm of glucocorticoid secretion, current efforts therefore focus on optimising replacement strategies. In addition, in recent years novel experimental therapies have been developed which target adrenal sex steroid synthesis in patients with CAH aiming to reduce co-morbidities associated with sex steroid excess. These developments will hopefully improve the health status and long-term outcomes in patients with congenital adrenal hyperplasia and adrenal insufficiency.

The Cochrane Library and safety of systemic corticosteroids for acute respiratory conditions in children: an overview of reviews

BACKGROUND

Acute respiratory conditions are a leading cause of childhood morbidity and mortality. Corticosteroids are effective and established treatments in some acute respiratory infections (e.g. croup) and asthma exacerbations; however, their role is controversial in other conditions owing to inconsistent effectiveness or safety concerns (e.g. bronchiolitis, acute wheeze).

OBJECTIVES

To examine clinically relevant short-term safety outcomes related to acute single or recurrent systemic short-term (<2 weeks) corticosteroid use based on systematic reviews of acute respiratory conditions.

METHODS

We searched the Cochrane Database of Systematic Reviews in February 2013 for systematic reviews comparing systemic corticosteroids with placebo for children (aged 0-18 years) with acute asthma, preschool wheezing, bronchiolitis, croup, pharyngitis/tonsillitis or pneumonia. We selected the following outcomes a priori: gastrointestinal (GI) bleeding and abdominal pain; behavioural effects (tremor or hyperactivity, jitteriness, irritability or emotional distress); hypertension; serious adverse events, including death, length of stay in hospital; and relapse leading to hospitalization. One reviewer extracted data and another reviewer independently verified data. Results were combined using Peto odds ratios and risk differences (RD) for dichotomous outcomes and mean differences for continuous outcomes.

MAIN RESULTS

Seven reviews containing 44 relevant randomized controlled trials were included. Three reviews were on asthma and one each on bronchiolitis, croup, wheeze and pharyngitis/tonsillitis. Six trials (2114 patients) assessed GI bleeding and/or abdominal pain and showed no significant differences between corticosteroids and placebo (1.5% vs. 1.8%, respectively). Various behavioural effects and hypertension/blood pressure were measured in four trials each (838 and 1617 patients, respectively), with no significant differences reported. None of the trials reported deaths in any of the treatment groups. Based on 17 trials (2056 patients), there were significantly fewer admissions at day 1 with corticosteroids (risk differences = -0.11, 95% confidence interval -0.18 to -0.05; Peto odds ratios = 0.63, 95% confidence interval 0.52 to 0.78). Based on 16 trials (1502 patients) corticosteroids resulted in over 8 fewer hours in hospital compared with placebo (mean differences = -8.49 hours, 95% confidence interval -1.76 to -3.23). There were significantly fewer relapses leading to hospitalization (13 trials, 1099 patients) with corticosteroids (Peto odds ratios 0.42, 95% confidence interval 0.23 to 0.76). While differences favouring corticosteroids in hospital-related outcomes were restricted to asthma and/or croup, we did not find any increase in hospital admission at day 1, length of stay or re-hospitalization in the other acute respiratory conditions.

AUTHORS' CONCLUSIONS

Practitioners may prescribe systemic corticosteroids in otherwise healthy children when indicated for the management of acute respiratory conditions (i.e. infections or asthma exacerbations) with minimal concern about short-term adverse effects.

Genomic redistribution of GR monomers and dimers mediates transcriptional response to exogenous glucocorticoid in vivo

Glucocorticoids (GCs) are commonly prescribed drugs, but their anti-inflammatory benefits are mitigated by metabolic side effects. Their transcriptional effects, including tissue-specific gene activation and repression, are mediated by the glucocorticoid receptor (GR), which is known to bind as a homodimer to a palindromic DNA sequence. Using ChIP-exo in mouse liver under endogenous corticosterone exposure, we report here that monomeric GR interaction with a half-site motif is more prevalent than homodimer binding. Monomers colocalize with lineage-determining transcription factors in both liver and primary macrophages, and the GR half-site motif drives transcription, suggesting that monomeric binding is fundamental to GR's tissue-specific functions. In response to exogenous GC in vivo, GR dimers assemble on chromatin near ligand-activated genes, concomitant with monomer evacuation of sites near repressed genes. Thus, pharmacological GCs mediate gene expression by favoring GR homodimer occupancy at classic palindromic sites at the expense of monomeric binding. The findings have important implications for improving therapies that target GR.

Regulation of Intracellular Copper by Induction of Endogenous Metallothioneins Improves the Disease Course in a Mouse Model of Amyotrophic Lateral Sclerosis

Mutations in SOD1 cause amyotrophic lateral sclerosis (ALS), an incurable motor neuron disease. The pathogenesis of the disease is poorly understood, but intracellular copper dyshomeostasis has been implicated as a key process in the disease. We recently observed that metallothioneins (MTs) are an excellent target for the modification of copper dyshomeostasis in a mouse model of ALS (SOD1(G93A)). Here, we offer a therapeutic strategy designed to increase the level of endogenous MTs. The upregulation of endogenous MTs by dexamethasone, a synthetic glucocorticoid, significantly improved the disease course and rescued motor neurons in SOD1(G93A) mice, even if the induction was initiated when peak body weight had decreased by 10%. Neuroprotection was associated with the normalization of copper dyshomeostasis, as well as with decreased levels of SOD1(G93A) aggregates. Importantly, these benefits were clearly mediated in a MT-dependent manner, as dexamethasone did not provide any protection when endogenous MTs were abolished from SOD1(G93A) mice. In conclusion, the upregulation of endogenous MTs represents a promising strategy for the treatment of ALS linked to mutant SOD1.

Prednisolone-containing liposomes accumulate in human atherosclerotic macrophages upon intravenous administration

Drug delivery to atherosclerotic plaques via liposomal nanoparticles may improve therapeutic agents' risk-benefit ratios. Our paper details the first clinical studies of a liposomal nanoparticle encapsulating prednisolone (LN-PLP) in atherosclerosis. First, PLP's liposomal encapsulation improved its pharmacokinetic profile in humans (n=13) as attested by an increased plasma half-life of 63h (LN-PLP 1.5mg/kg). Second, intravenously infused LN-PLP appeared in 75% of the macrophages isolated from iliofemoral plaques of patients (n=14) referred for vascular surgery in a randomized, placebo-controlled trial. LN-PLP treatment did however not reduce arterial wall permeability or inflammation in patients with atherosclerotic disease (n=30), as assessed by multimodal imaging in a subsequent randomized, placebo-controlled study. In conclusion, we successfully delivered a long-circulating nanoparticle to atherosclerotic plaque macrophages in patients, whereas prednisolone accumulation in atherosclerotic lesions had no anti-inflammatory effect. Nonetheless, the present study provides guidance for development and imaging-assisted evaluation of future nanomedicine in atherosclerosis.

FROM THE CLINICAL EDITOR

In this study, the authors undertook the first clinical trial using long-circulating liposomal nanoparticle encapsulating prednisolone in patients with atherosclerosis, based on previous animal studies. Despite little evidence of anti-inflammatory effect, the results have provided a starting point for future development of nanomedicine in cardiovascular diseases.

Intra-articular glucocorticoid injections and their effect on hypothalamic-pituitary-adrenal (HPA)-axis function

The use of intra-articular (IA) glucocorticoids for reducing pain and inflammation in patients with osteoarthritis, rheumatoid arthritis, and other inflammatory arthropathies is widespread among primary care physicians, specialists, and non-specialists in the United States. Injectable glucocorticoids have anti-inflammatory and analgesic properties which can be effective in improving clinical parameters such as pain, range of motion, and quality of life. After injection into the IA space, glucocorticoids may be systemically absorbed; the degree of absorption can depend on the size of the joint injected, the injectable glucocorticoid preparation used, the dosage, and the frequency of the injection. The adverse effects of intra-articular glucocorticoid injections (IAGC) can often be overlooked by both the patient and physicians who administer them, in particular the potential deleterious effect on the hypothalamic-pituitary-adrenal (HPA)-axis which can result in adrenal suppression and/or iatrogenic Cushing syndrome. In this paper we provide an overview on the often under-recognized effects of IAGC on HPA-axis function.

Associations of HSD11B1 polymorphisms with tacrolimus concentrations in Chinese renal transplant recipients with prednisone combined therapy

Tacrolimus requires close therapeutic drug monitoring because of its narrow therapeutic index and marked interindividual pharmacokinetic variation. In this study, we investigated the associations of polymorphisms in the gene encoding 11β-hydroxysteroid dehydrogenase type 1 (HSD11B1) with tacrolimus concentrations in Chinese renal transplant recipients during the early posttransplantation stage. A total of 258 renal transplant recipients receiving tacrolimus with prednisone (30 mg) combined therapy were genotyped for HSD11B1 rs846908, rs846910, rs4844880, and CYP3A5*3 polymorphisms. Tacrolimus trough concentrations were determined on days 6-9 after transplantation, measured by a chemiluminescent microparticle immunoassay. Among the CYP3A5 expressers, the dose-adjusted trough concentration (C0/D) of tacrolimus in HSD11B1 rs846908 AA homozygous individuals was considerably lower than found in GG+GA carriers [56.2 (23.9-86.6) versus 76.7 (12.6-220.0) (ng/ml)/(mg/kg), P = 0.0204]; HSD11B1 rs846910 AA homozygotes had a lower tacrolimus C0/D compared with GG+GA carriers [51.2 (23.9-86.6) versus 76.3 (12.6-220.0) (ng/ml)/(mg/kg), P = 0.0367]; carriers with the HSD11B1 rs4844880 AA genotype had a significantly lower tacrolimus C0/D with respect to carriers of TT+TA genotypes [61.3 (23.9-97.5) versus 77.2 (12.6-220.0) (ng/ml)/(mg/kg), P = 0.0002]; the HSD11B1 AA-AA-AA haplotype carriers had a lower tacrolimus C0/D than noncarriers [51.2 (23.9-86.6) versus 76.3 (12.6-220.0) (ng/ml)/(mg/kg), P = 0.0367]. These findings illustrate that the HSD11B1 genotypes are closely correlated with tacrolimus trough concentrations, suggesting that these polymorphisms may be useful for safer dosing of tacrolimus.

JNK and IKKβ phosphorylation is reduced by glucocorticoids in adipose tissue from insulin-resistant rats

OBJECTIVES

Peripheral insulin resistance (IR) is one of the main side effects caused by glucocorticoid (GC)-based therapies, and the molecular mechanisms of GC-induced IR are not yet fully elucidated. Thus, we aimed to investigate the effects of dexamethasone treatment on the main components of insulin and inflammatory signaling in the adipose tissue of rats.

MATERIALS/METHODS

Male Wistar rats received daily injections of dexamethasone (1mg/kg body weight (b.w.), intraperitoneally (i.p.)) for 5 days (DEX), whereas control rats received saline (CTL). The metabolic status was investigated, and the epididymal fat fragments were collected for lipolysis and western blot analyses.

RESULTS

The DEX rats became hyperglycemic, hyperinsulinemic, insulin resistant and glucose intolerant, compared with the CTL rats (P<0.05). The basal glycerol release in the fat fragments was 1.5-fold higher in the DEX rats (P<0.05). The phosphorylation of protein kinase B (PKB) at ser(473) decreased by 44%, whereas, the phosphorylation of insulin receptor substrate (IRS)-1 at ser(307) increased by 93% in the adipose tissue of the DEX rats after an oral bolus of glucose (P<0.05). The basal phosphorylation of c-jun-N-terminal kinase (JNK) and inhibitor of nuclear factor kappa-B (IKKβ) proteins was reduced by 46% and 58%, respectively, in the adipose tissue of the DEX rats (P<0.05). This was paralleled with a significant reduction (47%) in the glucocorticoid receptor (GR) protein content in the adipose tissue of the DEX rats (P<0.05).

CONCLUSION

The insulin-resistant status of rats induced by dexamethasone administration have PKB and IRS-1 activity attenuated in epididymal fat without increases in the phosphorylation of the proinflammatory signals JNK and IKKβ.

Strongyloides stercoralis infection in marmosets: replication of complicated and uncomplicated human disease and parasite biology

BACKGROUND

Strongyloides stercoralis can undergo an alternative autoinfective life cycle in the host, which, in some individuals can lead to a lethal infection. However, due to a number of factors, such as, the majority of those infected are from low-income backgrounds and the limitation in experimental models for studying human S. stercoralis, strongyloidiasis remains neglected. Improved knowledge of animal models that are susceptible to this parasite is needed in order to investigate the immunological mechanisms involved during infection and in particular to further understand the natural history of the autoinfective cycle.

METHODS

Callithrix penicillata were inoculated subcutaneously with 100 (n = 2), 300 (n = 4) or 500 (n = 9) third-stage infective larvae (L3i) of S. stercoralis of human origin. Three marmosets received smaller inocula (i.e., one received 100 and two received 300 L3i) to ensure a greater capacity to withstand the infection after immunosuppression, which was triggered by administration of dexamethasone during early patency. Qualitative faecal analyses began at 7 days post-infection (DPI), and semi-quantitative tests were also performed for the dexamethasone-treated primates and the three matched controls. During the necropsies, specimens of S. stercoralis were recovered and tissue fragments were processed for histopathology.

RESULTS

The mean prepatency and patency periods were 16.1 ± 3.0 and 161.1 ± 72.2 DPI, respectively. The marmosets typically tolerated the infection well, but immunosuppressed individuals exhibited higher numbers of larvae in the faeces and progressive clinical deterioration with late disseminated infection. In these cases, the number of females recovered was significantly higher than the number of inoculated L3i. Large quantities of larvae were observed migrating through the host tissues, and histopathology revealed pulmonary and intestinal injuries consistent with those observed in human strongyloidiasis.

CONCLUSIONS

Both complicated and uncomplicated strongyloidiasis occur in C. penicillata that is described as a susceptible small non-human primate model for S. stercoralis. This host permits the maintenance of a human strain of the parasite in the laboratory and can be useful for experimental investigations of strongyloidiasis. In parallel, we discuss data related to the autoinfective cycle that provides new insights into the biology of S. stercoralis.

Comparison of different glucocorticoid regimens in the management of classical congenital adrenal hyperplasia due to 21-hydroxylase deficiency

BACKGROUND

There are recommendations regarding the total dose of hydrocortisone to be administered in the treatment of classical congenital adrenal hyperplasia (CAH) to achieve the twin objectives of glucocorticoid replacement and control of hyperandrogenism. However, there is evidence gap regarding the breakup, timing and type of the steroid regimen.

OBJECTIVES

Efficacy of three different glucocorticoid regimens having the same total dose of steroid, differing in either the timing or type of evening steroid administered, in achieving biochemical control of the disease was assessed.

MATERIALS AND METHODS

The study was done in 13 prepubertal children with classical CAH over a 6-month period with 2 months devoted to each regimen. We used a prospective cross-over design using 10-15 mg/m(2) total dose of hydrocortisone. Two-fifths of the total dose of hydrocortisone was administered in the morning and one-fifth of the total dose was administered at noon in all the regimens. The regimens differed in the timing of the evening dose of hydrocortisone, 06.00-07.00 pm in regimen 1 and 09.00-10.00 pm in regimen 2. The third regimen had the evening dose of hydrocortisone replaced by an equivalent dose of prednisolone suspension which was administered at 10.00 pm. Serum 17-hydroxyprogesterone and testosterone levels were compared to assess the efficacy of treatment regimens.

RESULTS

The three different regimens were found to be similar in their ability to control 17-hydroxyprogesterone and testosterone levels. The percentage of patients with predefined criteria for biochemically controlled disease was similar in all the three regimens. However, there was a trend toward better control of 17-hydroxyprogesterone levels in patients receiving evening dose of prednisolone.

CONCLUSIONS

There is no significant advantage in administering the hydrocortisone dose late at night in patients with classical CAH.

Inhaled budesonide and oral dexamethasone prevent acute mountain sickness

BACKGROUND

This double-blind, randomized controlled trial aimed to investigate inhaled budesonide and oral dexamethasone compared with placebo for their prophylactic efficacy against acute mountain sickness after acute high-altitude exposure.

METHODS

There were 138 healthy young male lowland residents recruited and randomly assigned to receive inhaled budesonide (200 μg, twice a day [bid]), oral dexamethasone (4 mg, bid), or placebo (46 in each group). They traveled to 3900 m altitude from 400 m by car. Medication started 1 day before high-altitude exposure and continued until the third day of exposure. Primary outcome measure was the incidence of acute mountain sickness after exposure.

RESULTS

One hundred twenty-four subjects completed the study (42, 39, and 43 in the budesonide, dexamethasone, and placebo groups, respectively). Demographic characteristics were comparable among the 3 groups. After high-altitude exposure, significantly fewer participants in the budesonide (23.81%) and dexamethasone (30.77%) groups developed acute mountain sickness compared with participants receiving placebo (60.46%) (P = .0006 and P = .0071, respectively). Both the budesonide and dexamethasone groups had lower heart rate and higher pulse oxygen saturation (SpO2) than the placebo group at altitude. Only the budesonide group demonstrated less deterioration in forced vital capacity and sleep quality than the placebo group. Four subjects in the dexamethasone group reported adverse reactions.

CONCLUSIONS

Both inhaled budesonide (200 μg, bid) and oral dexamethasone (4 mg, bid) were effective for the prevention of acute mountain sickness, especially its severe form, compared with placebo. Budesonide caused fewer adverse reactions than dexamethasone.

Natural products in medicine: transformational outcome of synthetic chemistry

This review brings to the forefront key synthetic modifications on natural products (NPs) that have yielded successful drugs. The emphasis is placed on the power of targeted chemical transformations in enhancing the therapeutic value of NPs through optimization of pharmacokinetics, stability, potency, and/or selectivity. Multiple classes of NPs such as macrolides, opioids, steroids, and β-lactams used to treat a variety of conditions such as cancers, infections, inflammation are exemplified. Molecular modeling or X-ray structures of NP/protein complexes supporting the observed boost in therapeutic value of the modified NPs are also discussed. Significant advancement in synthetic chemistry, in structure determination, and in the understanding of factors controlling pharmacokinetics can now better position drug discovery teams to undertake NPs as valuable leads. We hope that the beneficial NPs synthetic modifications outlined here will reignite medicinal chemists' interest in NPs and their derivatives.

Targeting glucocorticoid side effects: selective glucocorticoid receptor modulator or glucocorticoid-induced leucine zipper? A perspective

Glucocorticoids (GCs) are steroid hormones that are necessary for life and important in health and disease. They regulate crucial homeostatic functions, including metabolism, cell growth, and development. Although GCs are regulated by circadian rhythm, increased production is associated with stress. Synthetic GCs are a valuable resource for anti-inflammatory and immunosuppressive therapy. Natural and synthetic GCs transduce signals mainly through GC receptor (GR) activation. Extensive research has explored the downstream targets of the GR, and optimization of GC therapy has required collaborative efforts. One highly promising approach involves new dissociative GR modulators. Because transrepression and transactivation of GR genes induce beneficial and adverse effects, respectively, this approach favors transrepression. Another approach involves the use of GC-dependent genes to generate proteins to mediate therapeutic GC effects. In a third approach, drug discovery is used to identify agents that selectively target GR isoforms to obtain differential gene transcription and effects. In this review, we focus on mechanisms of GR function compatible with the use of dissociative drugs. We highlight GC-induced leucine zipper (GILZ), a gene cloned in our laboratory, as a mediator of GC anti-inflammatory and immunosuppressive effects, to outline our perspective on the future of GC therapy.

Effects of acute cortisol administration on perceptual priming of trauma-related material

Intrusive memories are a hallmark symptom of posttraumatic stress disorder (PTSD). They reflect excessive and uncontrolled retrieval of the traumatic memory. Acute elevations of cortisol are known to impair the retrieval of already stored memory information. Thus, continuous cortisol administration might help in reducing intrusive memories in PTSD. Strong perceptual priming for neutral stimuli associated with a "traumatic" context has been shown to be one important learning mechanism that leads to intrusive memories. However, the memory modulating effects of cortisol have only been shown for explicit declarative memory processes. Thus, in our double blind, placebo controlled study we aimed to investigate whether cortisol influences perceptual priming of neutral stimuli that appeared in a "traumatic" context. Two groups of healthy volunteers (N = 160) watched either neutral or "traumatic" picture stories on a computer screen. Neutral objects were presented in between the pictures. Memory for these neutral objects was tested after 24 hours with a perceptual priming task and an explicit memory task. Prior to memory testing half of the participants in each group received 25 mg of cortisol, the other half received placebo. In the placebo group participants in the "traumatic" stories condition showed more perceptual priming for the neutral objects than participants in the neutral stories condition, indicating a strong perceptual priming effect for neutral stimuli presented in a "traumatic" context. In the cortisol group this effect was not present: Participants in the neutral stories and participants in the "traumatic" stories condition in the cortisol group showed comparable priming effects for the neutral objects. Our findings show that cortisol inhibits perceptual priming for neutral stimuli that appeared in a "traumatic" context. These findings indicate that cortisol influences PTSD-relevant memory processes and thus further support the idea that administration of cortisol might be an effective treatment strategy in reducing intrusive reexperiencing.

Improving outcomes in patients with adrenal insufficiency: a review of current and future treatments

INTRODUCTION

Adrenal insufficiency is a rare but life-threatening disease. Conventional therapy consists of glucocorticoid replacement using hydrocortisone administered two or three times daily. Although such therapy extends life expectancy, mortality is not normalized, and quality of life remains poor. This failure to restore normal health is thought to be due to the inability of conventional glucocorticoid replacement therapy to normalize total cortisol exposure and to respond to the increased need for glucocorticoids during illness and stress. Also, current management regimens do not restore or replicate the intrinsic circadian rhythm of cortisol secretion.

AREAS COVERED

This narrative review was based on a PubMed and Medline search of all English-language articles on the safety and efficacy of glucocorticoid replacement therapy in patients with adrenal insufficiency. Based on this search we discuss current treatment strategies in terms of the failure to maintain or normalize metabolism and quality of life in patients with adrenal insufficiency. The rationale for, and technology behind, the development of modified-release preparations of hydrocortisone are described, together with the evidence suggesting that hydrocortisone preparations that mimic the physiological circadian pattern of cortisol release are more effective than conventional glucocorticoid replacement therapies.

CONCLUSIONS

Modified-release hydrocortisone treatments for patients with adrenal insufficiency more closely mimic the physiological circadian pattern of cortisol secretion than conventional twice or thrice daily treatment. The available evidence suggests that these modified-release preparations should improve metabolic outcomes and quality of life.

Is dexamethasone an effective alternative to oral prednisone in the treatment of pediatric asthma exacerbations?

BACKGROUND

A short course of systemic corticosteroids is an important therapy in the treatment of pediatric asthma exacerbations. Although a 5-day course of oral prednisone or prednisolone has become the most commonly used regimen, dexamethasone has also been used for a shorter duration (1-2 days) with potential for improvement in compliance and palatability. We reviewed the literature to determine if there is sufficient evidence that dexamethasone can be used as an effective alternative in the treatment of pediatric asthma exacerbations in the inpatient setting.

METHODS

A Medline search was conducted on the use of dexamethasone in the treatment of asthma exacerbations in children. The studies selected were clinical trials comparing the efficacy of dexamethasone with prednisone. Meta-analysis was performed examining physician revisitation rates and symptomatic return to baseline.

RESULTS

Six completed pediatric clinical trials met the inclusion criteria. All of the pediatric trials found that prednisone is not superior to dexamethasone in treating mild to moderate asthma exacerbations. Meta-analysis demonstrated homogeneity between the dexamethasone and prednisone groups when examining symptomatic return to baseline and unplanned physician revisits after the initial emergency department encounter. Some studies found potential additional benefits of dexamethasone, including improved compliance and less vomiting.

CONCLUSIONS

The current literature suggests that dexamethasone can be used as an effective alternative to prednisone in the treatment of mild to moderate acute asthma exacerbations in children, with the added benefits of improved compliance, palatability, and cost. However, more research is needed to examine the role of dexamethasone in hospitalized children.

Glucocorticoids and fetal programming part 1: Outcomes

Fetal development is a critical period for shaping the lifelong health of an individual. However, the fetus is susceptible to internal and external stimuli that can lead to adverse long-term health consequences. Glucocorticoids are an important developmental switch, driving changes in gene regulation that are necessary for normal growth and maturation. The fetal hypothalamic-pituitary-adrenal (HPA) axis is particularly susceptible to long-term programming by glucocorticoids; these effects can persist throughout the life of an organism. Dysfunction of the HPA axis as a result of fetal programming has been associated with impaired brain growth, altered behaviour and increased susceptibility to chronic disease (such as metabolic and cardiovascular disease). Moreover, the effects of glucocorticoid-mediated programming are evident in subsequent generations, and transmission of these changes can occur through both maternal and paternal lineages.

Using physiologically-based pharmacokinetic-guided "body-on-a-chip" systems to predict mammalian response to drug and chemical exposure

The continued development of in vitro systems that accurately emulate human response to drugs or chemical agents will impact drug development, our understanding of chemical toxicity, and enhance our ability to respond to threats from chemical or biological agents. A promising technology is to build microscale replicas of humans that capture essential elements of physiology, pharmacology, and/or toxicology (microphysiological systems). Here, we review progress on systems for microscale models of mammalian systems that include two or more integrated cellular components. These systems are described as a "body-on-a-chip", and utilize the concept of physiologically-based pharmacokinetic (PBPK) modeling in the design. These microscale systems can also be used as model systems to predict whole-body responses to drugs as well as study the mechanism of action of drugs using PBPK analysis. In this review, we provide examples of various approaches to construct such systems with a focus on their physiological usefulness and various approaches to measure responses (e.g. chemical, electrical, or mechanical force and cellular viability and morphology). While the goal is to predict human response, other mammalian cell types can be utilized with the same principle to predict animal response. These systems will be evaluated on their potential to be physiologically accurate, to provide effective and efficient platform for analytics with accessibility to a wide range of users, for ease of incorporation of analytics, functional for weeks to months, and the ability to replicate previously observed human responses.

Changes in blood glucose and cortisol levels after epidural or shoulder intra-articular glucocorticoid injections in diabetic or nondiabetic patients

OBJECTIVE

The aim of this study was to investigate the changes in blood glucose and cortisol levels after glucocorticoid injections into the epidural space or the glenohumeral joint in patients with or without diabetes.

DESIGN

Twenty-nine patients with sciatic or shoulder pain were included. Fasting plasma glucose and cortisol levels were measured at baseline. After glucocorticoid injection, the levels were measured again after 1, 7, and 21 days. The patients were divided into four subgroups according to the presence of diabetes and site of injection.

RESULTS

In all subgroups, fasting plasma glucose levels were significantly higher 1 day after injection but returned to baseline 7 days after the injection. Compared with baseline, cortisol levels were markedly reduced 1 and 7 days after the injection. For both the diabetic and nondiabetic subjects, this drop was significantly larger in the epidural injection than the glenohumeral joint injection. At 21 days after injection, cortisol levels returned to baseline in all subgroups except in the diabetic patients treated with epidural injections.

CONCLUSIONS

These findings indicate a need for caution when using local glucocorticoid injection therapy in diabetic patients, most notably when an epidural injection is given. It is also recommended that diabetic patients take more time off before receiving a succeeding epidural glucocorticoid injection.

A myelopoiesis gene signature during remission in anti-neutrophil cytoplasm antibody-associated vasculitis does not predict relapses but seems to reflect ongoing prednisolone therapy

A myelopoiesis gene signature in circulating leucocytes, exemplified by increased myeloperoxidase (MPO) and proteinase 3 (PR3) mRNA levels, has been reported in patients with active anti-neutrophil cytoplasm antibody-associated vasculitis (AAV), and to a lesser extent during remission. We hypothesized that this signature could predict disease relapse. mRNA levels of PR3, MPO, selected myelopoiesis transcription factors [CCAAT/enhancer binding protein α (CEBP-α), CCAAT/enhancer binding protein β (CEBP-β), SPI1/PU.1-related transcription factor (SPIB), spleen focus forming virus proviral integration oncogene, PU.1 homologue (SPI1)] and microRNAs (miRNAs) from patient and control peripheral blood mononuclear cells (PBMC) and polymorphonuclear cells (PMN) were analysed and associated with clinical data. Patients in stable remission had higher mRNA levels for PR3 (PBMC, PMN) and MPO (PBMC). PR3 and SPIB mRNA correlated positively in controls but negatively in patient PBMC. Statistically significant correlations existed between PR3 mRNA and several miRNAs in controls, but not in patients. PR3/MPO mRNA levels were not associated with previous or future relapses, but correlated with steroid treatment. Prednisolone doses were negatively linked to SPIB and miR-155-5p, miR-339-5p (PBMC) and to miR-221, miR-361 and miR-505 (PMN). PR3 mRNA in PBMC correlated with time since last flare, blood leucocyte count and estimated glomerular filtration rate. Our results show that elevated leucocyte PR3 mRNA levels in AAV patients in remission do not predict relapse. The origin seems multi-factorial, but to an important extent explainable by prednisolone action. Gene signatures in patients with AAV undergoing steroid treatment should therefore be interpreted accordingly.

Challenges in the diagnosis and management of autoimmune hepatitis

BACKGROUND

Autoimmune hepatitis has diverse clinical phenotypes and outcomes that challenge current diagnostic criteria and management algorithms.

OBJECTIVES

To highlight the major difficulties in diagnosis and management, describe the efforts to ease them and encourage further progress in problem solving.

METHODS

The MEDLINE database was reviewed for published experiences from 1984 to 2013.

RESULTS

Acute or acute severe (fulminant) hepatitis, asymptomatic mild disease, and histological findings of centrilobular necrosis or bile duct injury can confound diagnosis and treatment. Continuation of conventional therapy until normal liver test results and liver tissue reduces the frequency of relapse, but does not prevent its occurrence. Problematic patients can be identified using mathematical models, clinical phenotype, serological markers and the speed of improvement after treatment; however, their recognition and treatment are inconsistent. Mycophenolate mofetil can rescue patients with azathioprine intolerance but is less effective for refractory disease. Budesonide in combination with azathioprine can be used frontline, but is effective primarily in noncirrhotic, uncomplicated disease. Molecular and cellular interventions are feasible but largely unevaluated.

DISCUSSION

Resolution of the current challenges requires revision of diagnostic criteria, characterization of biological markers that reflect pathogenic pathways, development of dynamic indexes based on changes in disease behaviour, and introduction of new pharmacological, molecular and cellular interventions that have undergone rigorous evaluation.

CONCLUSION

These challenges reflect important remediable deficiencies in current management.

Corticosteroids in the treatment of acute exacerbations of chronic obstructive pulmonary disease

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a chronic and progressive disease that affects an estimated 10% of the world's population over the age of 40 years. Worldwide, COPD ranks in the top ten for causes of disability and death. Given the significant impact of this disease, it is important to note that acute exacerbations of COPD (AECOPD) are by far the most costly and devastating aspect of disease management. Systemic steroids have long been a standard for the treatment of AECOPD; however, the optimal strategy for dosing and administration of these medications continues to be debated.

OBJECTIVE

To review the use of corticosteroids in the treatment of acute exacerbations of COPD.

MATERIALS AND METHODS

Literature was identified through PubMed Medline (1950-February 2014) and Embase (1950-February 2014) utilizing the search terms corticosteroids, COPD, chronic bronchitis, emphysema, and exacerbation. All reference citations from identified publications were reviewed for possible inclusion. All identified randomized, placebo-controlled trials, meta-analyses, and systematic reviews evaluating the efficacy of systemic corticosteroids in the treatment of AECOPD were reviewed and summarized.

RESULTS

The administration of corticosteroids in the treatment of AECOPD was assessed. In comparison to placebo, systemic corticosteroids improve airflow, decrease the rate of treatment failure and risk of relapse, and may improve symptoms and decrease the length of hospital stay. Therefore, corticosteroids are recommended by all major guidelines in the treatment of AECOPD. Existing literature suggests that low-dose oral corticosteroids are as efficacious as high-dose, intravenous corticosteroid regimens, while minimizing adverse effects. Recent data suggest that shorter durations of corticosteroid therapy are as efficacious as the traditional treatment durations currently recommended by guidelines.

CONCLUSION

Systemic corticosteroids are efficacious in the treatment of AECOPD and considered a standard of care for patients experiencing an AECOPD. Therefore, systemic corticosteroids should be administered to all patients experiencing AECOPD severe enough to seek emergent medical care. The lowest effective dose and shortest duration of therapy should be considered.

Steroid-free and steroid withdrawal protocols in heart transplantation: the review of literature

Corticosteroids (CSs) are still the mainstay of induction, rescue, and maintenance in heart transplantation (HTx). However, their use is associated with significant and well-documented side effects usually related to the dose administered and the duration of therapy. Moreover, CSs interfere with the recipient's quality of life and with the active process of graft tolerance. Physicians have been exploring ways to avoid or reduce CSs in association with other immunosuppressive drugs, minimizing side effects and costs. The regimens are classified as steroid-free or steroid withdrawal protocols. The studies analyzed in this review come to similar conclusions as benefits and adverse consequences: steroid-free protocols should be advisable and mandatory in pediatric patients, insulin-dependent diabetes mellitus (IDDM), presence of infection, familial metabolic disorders/obesity, severe osteoporosis, and in the elderly. On the other hand, steroid withdrawal can be successfully achieved in 50-80%, with late better than early withdrawal, no increase in rejection-related mortality, no adverse impact on survival, and probably a better quality of live. Safety and efficacy can certainly be improved by an individualized approach to the transplant recipient.

Dual-release Hydrocortisone in Addison's Disease - A Review of the Literature

In patients with adrenal insufficiency, glucocorticoids (GCs) are insufficiently secreted and GC replacement is essential for health and, indeed, life. Despite GC-replacement therapy, patients with adrenal insufficiency have a greater cardiovascular risk than the general population, and suffer from impaired health-related quality of life. Although the aim of the replacement GC therapy is to reproduce as much as possible the physiological pattern of cortisol secretion by the normal adrenal gland, the pharmacokinetics of available oral immediate-release hydrocortisone or cortisone make it impossible to fully mimic the cortisol rhythm. Therefore, there is an unmet clinical need for the development of novel pharmaceutical preparations of hydrocortisone, in order to guarantee a more physiological serum cortisol concentration time-profile, and to improve the long-term outcome in patients under GC substitution therapy.

Monitoring prednisolone and prednisone in saliva: a population pharmacokinetic approach in healthy volunteers

BACKGROUND

Prednisolone (PLN) is a widely used corticosteroid in a variety of immune-mediated diseases. Treatment regimes generally consist of empirically derived treatment doses, whereas therapeutic response among patients is highly variable. Drug monitoring of serum PLN levels might support a more rational approach to dose selection, yet is invasive and laborious. In analogy to cortisol, salivary PLN may offer a good alternative for serum PLN, being a representative approximation of free serum PLN. The aims of this study were to evaluate the correlation between free serum and salivary PLN levels and to quantify this relationship within a population pharmacokinetic model.

METHODS

PLN and prednisone (PN) concentrations were measured in 396 samples from 19 healthy volunteers after oral ingestion of 80 mg PLN. Measurements in serum, ultrafiltrate, and saliva were performed with a recently validated liquid chromatography tandem mass spectrometry method. Population pharmacokinetic analysis was performed with nonlinear mixed effect modeling using NONMEM.

RESULTS

Salivary PLN levels correlated well with free serum PLN levels (r = 0.931, P < 0.01). A weaker correlation was found for PN (r = 0.318, P < 0.01), which may be explained by the finding that salivary PN levels mainly seemed to consist of PLN enzymatically converted to PN. Total and free serum PLN concentrations decreased over time after drug administration and showed a nonlinear mutual relationship, consistent with concentration-dependent protein binding. Modeled PLN pharmacokinetics corresponded with previous reports. Low to moderate interindividual variability was found for V/F and CL/F (coefficients of variation were 13.8% and 14.6%, respectively). Free and salivary PLN showed a nonlinear relationship with total PLN. An equation predicting free serum levels from salivary levels was successfully derived from the data.

CONCLUSIONS

This study is the first to describe the relationship between salivary and (free) serum PLN using a population pharmacokinetic model. Salivary PLN was found to be a reliable predictor of free and total serum PLN in healthy volunteers. The results of this study encourage further exploration of the use of saliva as a noninvasive and feasible method for drug monitoring of PLN.

Review article: The prevention and reversal of hepatic fibrosis in autoimmune hepatitis

BACKGROUND

Immunosuppressive treatment of autoimmune hepatitis can prevent or reverse hepatic fibrosis, but these anti-fibrotic effects are inconsistent secondary gains.

AIM

To describe the anti-fibrotic effects of current therapies for autoimmune hepatitis, discuss the pathogenic mechanisms of hepatic fibrosis that might be targeted by anti-fibrotic interventions, indicate the non-invasive diagnostic tests of hepatic fibrosis that must be validated in autoimmune hepatitis and to suggest promising treatment opportunities.

METHODS

Studies cited in PubMed from 1972 to 2013 for autoimmune hepatitis, hepatic fibrosis, cirrhosis, anti-fibrotic therapy and non-invasive tests of hepatic fibrosis were selected.

RESULTS

Hepatic fibrosis improves in 53-57% of corticosteroid-treated patients with autoimmune hepatitis; progressive fibrosis slows or is prevented in 79%; and cirrhosis may be reversed. Progressive hepatic fibrosis is associated with liver inflammation, and the inability to fully suppress inflammatory activity within 12 months is associated with progression to cirrhosis (54%) and death or need for liver transplantation (15%). Liver tissue examination remains the gold standard for assessing hepatic fibrosis, but laboratory and radiological tests may be useful non-invasive methods to measure the fibrotic response. Severe liver inflammation can confound radiological assessments, and the preferred non-invasive test in autoimmune hepatitis is uncertain. Individualised treatment adjustments and adjunctive anti-fibrotic therapies are poised for study in this disease.

CONCLUSIONS

The prevention and reversal of hepatic fibrosis are achievable objectives in autoimmune hepatitis. Strategies that evaluate individualised therapies adjusted to the rapidity and completeness of the inflammatory response, and the use of adjunctive anti-fibrotic interventions, must be evaluated.

Routine drug and food interactions during antihelminthic treatment of neurocysticercosis: a reason for the variable efficacy of albendazole and praziquantel?

Neurocysticercosis (NC) or infection of the central nervous system with Taenia solium larvae is a leading cause of preventable seizures and epilepsy in endemic regions across the globe. Albendazole and praziquantel are commonly used antihelminthic agents to treat NC; however, viable cysts persist in the majority of patients, putting them at risk for future seizures and other neurological complications. Because of their pharmacokinetic profiles, albendazole and praziquantel have the potential to interact with many different drugs. During antihelminthic treatment, antiepileptic drugs and corticosteroids are commonly co-administered to manage seizures and cerebral edema; however, the most commonly used agents from these drug classes are known to significantly alter plasma concentrations of albendazole and praziquantel. The overarching issue with drug interactions during the treatment of NC is whether or not they have clinical relevance, as the plasma concentrations of albendazole and praziquantel have not been directly linked with eradication of viable cysts. Future studies should attempt to evaluate the validity of a causal relationship between antihelminthic plasma concentrations and outcomes so that drug interactions can be better understood and managed and so that treatment can be optimized.

Cytochrome P450 enzyme regulation by glucocorticoids and consequences in terms of drug interaction

INTRODUCTION

Due to their multiple effects, glucocorticoids (GCs) have versatile medical uses. They can regulate many xenobiotic-metabolizing enzymes of the cytochrome P450 (CYP) superfamily, and thus, influence pharmacotherapy.

AREAS COVERED

The aim of this paper is to summarize the molecular effects of GCs on CYP as well as the available clinical evidence on drug-drug interactions (DDIs) between GCs and other drugs in which GCs influence the metabolism of other medicines through modifying CYP activity. We used the factographic database DRUGDEX® along with bibliographic searches.

EXPERT OPINION

Most of the literature reported CYP3A4 induction by GCs, but this was not proved in all research. As the conclusions on these DDIs are conflicting, there are several issues to be considered like the dosage of GCs, the length of GCs treatment and concomitant therapy, all of which can have an additive inducing effect. Further, in designing a DDI study, crossover studies are preferred. A literature search of the abovementioned information resources provided dissimilar results.