Several reasons why ketamine as a neuroplastic agent may have failed to prevent postoperative delirium: Implications for future protocols

Ketamine exerts anti-inflammatory, neuroprotective and neuroplastic activity, therefore it may counteract the neurotoxic processes underlying postoperative delirium. However, the majority of studies in this field failed. We identified several pharmacological reasons why these studies may have failed, together with suggestions of how to remediate them. Among them, the interaction with intravenous general anesthetics exerting the opposite effect on GABA interneurons than ketamine may be of principal importance. We suggest biomarkers which may elucidate the influence of this interaction on the different steps of neuroplastic pathways. We hypothesize that administering ketamine before or after general anesthesia could both prevent the interactions and strengthen the effect of ketamine by timing surgery within the climax of ketamine-induced neuroplastic changes or by stabilizing AMPA receptors. It is vital to deal with these questions because the protocols of ongoing studies are based again on the administration of ketamine during general anesthesia (the major identified pitfall).

Structure-based virtual screening discovers novel kidney-type glutaminase inhibitors

Glutaminase (GLS) serves a critical bioenergetic role for malignant tumor growth and has become a valuable therapeutic target for cancer treatment. Herein, we performed a structure-based virtual screening to discover novel GLS inhibitors and provide information for developing new GLS inhibitors. We identified critical pharmacological interactions in the GLS1 binding site by analyzing the known GLS1 inhibitors and selected potential inhibitors based on their docking score and pharmacological interactions. The inhibitory effects of compounds were further confirmed by enzymatic and cell viability assays. We treated colorectal cancer and triple-negative breast cancer cells with the selected candidates and measured the inhibitory efficacy of hit compounds on cell viability. In total, we identified three GLS1 inhibitors. The compounds identified from our structure-based virtual screening methodology exhibited great anticancer potential as a lead targeting glutamine metabolism.

Interactions of clinical relevance associated with concurrent administration of prescription drug and food or medicinal plants: a systematic review protocol

BACKGROUND

An inadequate combination of prescription drugs with food or medicinal plants could cause adverse effects in patients or produce negative therapeutic results. Therefore, this generic systematic review protocol aims to identify and synthesize the literature on clinical characteristics and safety issues of these types of pharmacological interactions occurring in children, adolescents, adults, pregnant/lactating women, and older adults.

METHODS/DESIGN

This generic protocol follows the stated guidelines from the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols (PRISMA-P) statement. A literature search will be performed in PubMed, Scopus, and Virtual Health Library (VHL) electronic databases from 1960 till present for studies reporting clinical characteristics and safety issues associated with pharmacological interactions occurring between prescription drugs and food or medicinal plants in participants from birth-age to ≥ 65-year-old, including pregnant/lactating women. Lateral searching will be carried out in PubMed via related citation. Two reviewers will carry out an independent evaluation of eligible studies as well as the corresponding data extraction of the selected ones. Subsequently, the methodological quality evaluation of the selected articles will be completed using the corresponding Joanna Briggs Institute Checklists. Moreover, the quality of evidence will be graded according to the criteria of the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) Working Group. Quantitative research in humans comprising clinical trials and clinical, comparative and, observational studies will be included. The main outcomes of this protocol involve reported potential food-drug and herb-drug interactions, associated safety issues, and adverse reactions along with the generic name of the prescribed drug and the scientific name of the food and medicinal plants involved in these types of pharmacological interactions. Finally, findings extracted from the selected studies will be summarized in a narrative synthesis.

DISCUSSION

This generic systematic review protocol seeks to synthesize and critically evaluate current knowledge besides to identify any comprehension gaps in the concurrent administration of prescription drugs with food and herbs. By achieving a better understanding of this topic, this information will allow healthcare professionals to develop useful strategies to recognize, manage, and prevent these types of pharmacological interactions at different age stages, including pregnant/lactating women.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42018117308.

Multi-target antidiabetic mechanisms of mexicanolides from Swietenia humilis

BACKGROUND

Swietenia humilis seeds are consumed in Mexico to treat type 2 diabetes; the antihyperglycemic effect of this species was previously demonstrated and related to the presence of tetranortriterpenoids of the mexicanolide class.

PURPOSE AND STUDY DESIGN

The present investigation was conducted to determine the mechanism of action of selected mexicanolides, including 2-hydroxy-destigloyl-6-deoxyswietenine acetate (1), methyl-2-hydroxy-3-β-tigloyloxy-1-oxomeliac-8(30)-enate (2) and humilinolide H (3), using in vivo experiments with hyperglycemic mice, and cell-based models.

METHODS

Nicotinamide-streptozotocin hyperglycemic mice (50-130 mg/kg, i.p.) were used to build antihyperglycemic drug-response curves using an oral glucose tolerance test model. In vitro studies were carried out on INSE1, H4IIE and C2C12 cells to assess insulin secretion, glucose-6-phosphatase inhibition, glucose uptake and mitochondrial bioenergetics, respectively.

RESULTS

The combination of the decoction of S. humilis or 2-hydroxy-destigloyl-6-deoxyswietenine acetate (mexicanolide 1) with glibenclamide resulted in a reduction of the antihyperglycemic effect while a significant increase was observed when they were dosed with metformin. These effects were related to K_ATP SUR blockade, insulin secretion in INSE1 cells, and modulation of 5-HT₂ receptors. Furthermore, mexicanolides 1-3 inhibited glucose-phosphatase in H4IIE cells, and enhanced glucose uptake and spare respiratory capacity in C2C12 myotubes.

CONCLUSION

S. humilis mexicanolides interact with pharmacological targets at pancreas (K_ATP channels), liver (glucose-6-phosphatase), and skeletal muscle (mitochondria and possibly glucose transporters) to modulate glucose homeostasis, and could be a promising resource to treat type 2 diabetes.

Influence of 25-hydroxyvitamin D3 and 1,25-dihydroxyvitamin D3 on expression of P-glycoprotein and cytochrome P450 3A in sheep

In order to improve calcium and phosphorus balance, beef cattle and dairy cows can be supplemented with vitamin D. However, different vitamin D metabolites have been shown to increase expression of P-glycoprotein (P-gp, MDR1, ABCB1) and cytochrome P450 3A (CYP3A) in rodents as well as in cell culture systems. As such interferences might have an impact on pharmacokinetics of some drugs widely-used in veterinary medicine, we investigated the expression of P-gp, CYP3A, vitamin D receptor (VDR), pregnane X receptor (PXR) and retinoid X receptor α (RXRα) in sheep either treated orally with 6μg/kg body weight (BW) 25-hydroxyvitamin D₃ (OHD₃) for ten days before sacrifice or 12h after intravenous injection of 0.5μg/kg BW 1,25-dihydroxyvitamin D₃ (1,25- (OH)₂D₃). Down-regulation of ruminal, jejunal and hepatic, but not renal P-gp could be found with 25-OHD₃ supplementation. Interestingly, this effect on P-gp was not observed in tissues from 1,25-(OH)₂D₃-treated sheep. In contrast, 1,25-(OH)₂D₃ induced a significant up-regulation of renal and jejunal CYP3A expression, while 25-OHD₃ had no impact. Renal expression of VDR and PXR was also increased by treatment with 1,25-(OH)₂D₃, while jejunal PXR expression was only stimulated in sheep supplemented with 25-OHD₃. Either treatments increased renal, but not ruminal, jejunal or hepatic expression of RXRα. These results demonstrate that the impact of large doses of vitamin D metabolites on different target organs and potential interactions with other medications should be further investigated in vitro and in vivo to understand the effects of vitamin D metabolites on metabolism and excretion pathways in livestock.

Metabolic complete response with vinflunine as second-line therapy in a kidney-transplanted patient with advanced urothelial carcinoma: a case report

Background

Patients undergone kidney transplantation present higher risk of Urothelial Carcinoma (UC) development and represent a subgroup of special interest. To date, vinflunine is the only drug approved in Europe for the treatment of advanced UC after failure of platinum-based chemotherapy. However, to our knowledge, no data on the concomitant administration of vinflunine and immunosuppressive agents are available.

Case presentation

The patient, a 45 years old Caucasian male, presented poorly differentiated UC of the bladder recurred after initial cystectomy with abdominal lymphadenopathies evidenced by FDG-PET/CT. Previously, at the age of 22, he had post-glomerulonephritis renal failure and underwent kidney transplantation from deceased donor. Since then, he has been in treatment with immunosuppressive therapy. At the time of UC recurrence, he was on treatment with cyclosporine. After progression to platinum-based chemotherapy, he received second-line therapy with vinflunine resulting in a complete metabolic response after two cycles. However, despite several dose reductions, the patient experienced severe hematologic toxicity. The pharmacological interaction between vinflunine and cyclosporine, both metabolized by CYP 3A4, may explain the excellent result and the concomitant severe toxicity.

Conclusions

Vinflunine is active on UC developed in kidney transplanted patients. However, special attention should be paid to concomitant administration with immunosuppressive agents that could result in increased toxicity.

Pharmacological interaction between valproic acid and carbapenem: what about levels in pediatrics?

Valproic acid (VPA) is the most commonly used antiepileptic drug in pediatric patients, but its major drawback is its multiple pharmacological interactions.

OBJECTIVE

To study children who had been simultaneously treated with carbapenems and valproic acid, considering drug levels, pharmacological interactions and clinical follow-up.

MATERIAL AND METHODS

Retrospective study of children who simultaneously received treatment with VPA and carbapenems between January 2003 and December 2011. Demographic variables, indication of treatment, dose, VPA plasma levels, interactions, clinical manifestations and medical management were analyzed.

RESULTS

28 children with concomitant treatment with both drugs were included in the study. 64.3% were males. 78.6% of the interactions were observed in the Intensive Care Unit. 60.7% of children had been previously treated VPA and its major indication were generalized seizures. Basal plasma levels of VPA were recorded in 53% and at 24 h after admittance in 60%. "40% of basal VPA levels were below therapeutic range prior to the administration of carbapenem. After the introduction of carbapenem 88% of level determinations were below therapeutic range". 54.5% of the patients that were chronically receiving VPA and had good control of epilepsy before admission had seizures during the coadministration. One patient that was on VPA before admission but with bad control of epilepsy worsened, and one patient that acutely received VPA did not achieve seizure freedom. In these cases it was necessary to either increase VPA dose or change to a different antiepileptic drug.

CONCLUSIONS

Little is known about the mechanism of pharmacologic interactions between carbapenems and VPA, but it leads to a reduction in plasma levels that may cause a loss of seizure control, so simultaneous use of both drugs should be avoided when possible. If not, VPA levels should be monitored.