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Antimicrobial Agents and Chemotherapy Oct 2023Accumulating evidence supports the use of higher doses of rifampicin for tuberculosis (TB) treatment. Rifampicin is a potent inducer of metabolic enzymes and drug...
Accumulating evidence supports the use of higher doses of rifampicin for tuberculosis (TB) treatment. Rifampicin is a potent inducer of metabolic enzymes and drug transporters, resulting in clinically relevant drug interactions. To assess the drug interaction potential of higher doses of rifampicin, we compared the effect of high-dose rifampicin (40 mg/kg daily, RIF40) and standard-dose rifampicin (10 mg/kg daily, RIF10) on the activities of major cytochrome P450 (CYP) enzymes and P-glycoprotein (P-gp). In this open-label, single-arm, two-period, fixed-order phenotyping cocktail study, adult participants with pulmonary TB received RIF10 (days 1-15), followed by RIF40 (days 16-30). A single dose of selective substrates (probe drugs) was administered orally on days 15 and 30: caffeine (CYP1A2), tolbutamide (CYP2C9), omeprazole (CYP2C19), dextromethorphan (CYP2D6), midazolam (CYP3A), and digoxin (P-gp). Intensive pharmacokinetic blood sampling was performed over 24 hours after probe drug intake. In all, 25 participants completed the study. Geometric mean ratios (90% confidence interval) of the total exposure (area under the concentration versus time curve, RIF40 versus RIF10) for each of the probe drugs were as follows: caffeine, 105% (96%-115%); tolbutamide, 80% (74%-86%); omeprazole, 55% (47%-65%); dextromethorphan, 77% (68%-86%); midazolam, 62% (49%-78%), and 117% (105%-130%) for digoxin. In summary, high-dose rifampicin resulted in no additional effect on CYP1A2, mild additional induction of CYP2C9, CYP2C19, CYP2D6, and CYP3A, and marginal inhibition of P-gp. Existing recommendations on managing drug interactions with rifampicin can remain unchanged for the majority of co-administered drugs when using high-dose rifampicin. Clinical Trials registration number NCT04525235.
Topics: Adult; Humans; Cytochrome P-450 CYP1A2; Midazolam; Cytochrome P-450 CYP2D6; Caffeine; Rifampin; Cytochrome P-450 CYP2C19; Cytochrome P-450 CYP3A; Dextromethorphan; Tolbutamide; Cytochrome P-450 CYP2C9; Cytochrome P-450 Enzyme System; Omeprazole; Drug Interactions; Tuberculosis, Pulmonary; Digoxin
PubMed: 37768317
DOI: 10.1128/aac.00683-23 -
Membranes Sep 2023High levels of oxidative stress are implicated in hypoxia, a physiological response to low levels of oxygen. Evidence supports a connection between this response and...
High levels of oxidative stress are implicated in hypoxia, a physiological response to low levels of oxygen. Evidence supports a connection between this response and depression. Previous studies indicate that tryptophan hydroxylase can be negatively affected in hypoxia, impairing serotonin synthesis and downstream pathways. Some studies also hypothesize that increasing hypoxia-inducible factor-1 (HIF-1) levels may be a new therapeutic modality for depression. Hence, this study delved into the influence of hypoxia on the cellular response to drugs designed to act in depression. By the induction of hypoxia in SH-SY5Y cells through a hypoxia incubator chamber or Cobalt Chloride treatment, the effect of Mirtazapine, an antidepressant, and other drugs that interact with serotonin receptors (TCB-2, Dextromethorphan, Ketamine, Quetiapine, Scopolamine, Celecoxib, and Lamotrigine) on SH-SY5Y cellular viability and morphology was explored. The selection of drugs was initially conducted by literature search, focusing on compounds with established potential for employment in depression therapy. Subsequently, we employed in silico approaches to forecast their ability to traverse the blood-brain barrier (BBB). This step was particularly pertinent as we aimed to assess their viability for inducing potential antidepressant effects. The effect of these drugs in hypoxia under the inhibition of HIF-1 by Echinomycin was also tested. Our results revealed that all the potential repurposed drugs promoted cell viability, especially when hypoxia was chemically induced. When combined with Echinomycin, all drugs decreased cellular viability, possibly by the inability to interact with HIF-1.
PubMed: 37755222
DOI: 10.3390/membranes13090800 -
Biomedicine & Pharmacotherapy =... Nov 2023The analgesic effects of sigma-1 antagonists are undisputed, but the effects of sigma-1 agonists on pain are not well studied. Here, we used a mouse model to show that...
The analgesic effects of sigma-1 antagonists are undisputed, but the effects of sigma-1 agonists on pain are not well studied. Here, we used a mouse model to show that the administration of the sigma-1 agonists dextromethorphan (a widely used antitussive drug), PRE-084 (a standard sigma-1 ligand), and pridopidine (a selective drug being investigated in clinical trials for the treatment of neurodegenerative diseases) enhances PGE2-induced mechanical hyperalgesia. Superficial plantar incision induced transient weight-bearing asymmetry at early time points, but the mice appeared to recover at 24 h, despite noticeable edema and infiltration of neutrophils (a well-known cellular source of PGE2) at the injured site. Sigma-1 agonists induced a relapse of weight bearing asymmetry in a manner dependent on the presence of neutrophils. The effects of sigma-1 agonists were all reversed by administration of the sigma-1 antagonist BD-1063 in wild-type mice, and were absent in sigma-1 knockout mice, supporting the selectivity of the effects observed. The proalgesic effects of sigma-1 agonism were also abolished by the TRP antagonist ruthenium red and by in vivo resiniferatoxin ablation of TRPV1 + peripheral sensory neurons. Therefore, sigma-1 agonism exacerbates pain-like responses in mice with a mild inflammatory state through the action of TRPV1 + nociceptors. We also show that sigma-1 receptors are present in most (if not all) mouse and human DRG neurons. If our findings translate to humans, further studies will be needed to investigate potential proalgesic effects induced by sigma-1 agonism in patients treated with sigma-1 agonists.
PubMed: 37729726
DOI: 10.1016/j.biopha.2023.115534 -
Journal of Pharmacy & Bioallied Sciences 2023This study was done to evaluate the knowledge of community pharmacists-working in Saudi Arabia-regarding over-the-counter opioid-related and opioid-containing...
OBJECTIVES
This study was done to evaluate the knowledge of community pharmacists-working in Saudi Arabia-regarding over-the-counter opioid-related and opioid-containing medications.
MATERIALS AND METHODS
A quantitative cross-sectional study was conducted using an online questionnaire that was distributed through social media and taken to the community pharmacists in person. A total of 101 responders were reached in a period of around 3 weeks.
RESULTS
Most of the pharmacists working in community pharmacies in Saudi Arabia are non-Saudi (85.15%), males (88.12%), and the majority are holders of bachelor's degrees (85.15%). More than half of the participants spend a considerably sufficient time with the patient 6-10 minutes (60.4%). The availability of a private counseling room in community pharmacies is significantly low (21.78%). Only (69.41%) of participants always counsel the patient before dispensing opioid-related medications. Most of the participants (84.76%) believe that all over-the-counter opioid-related and opioid-containing medications should be restricted to avoid drug abuse.
CONCLUSION
A little neglect from pharmacists' side regarding dispensing such medications was observed; thus, there is a significant need to raise their awareness regarding over-the-counter opioid abuse.
PubMed: 37705858
DOI: 10.4103/jpbs.jpbs_349_23 -
Arquivos de Neuro-psiquiatria Aug 2023The spectrum of neuropsychiatric phenomena observed in amyotrophic lateral sclerosis (ALS) is wide and not fully understood. Disorders of laughter and crying stand among...
Definitions, phenomenology, diagnosis, and management of the disorders of laughter and crying in amyotrophic lateral sclerosis (ALS): Consensus from ALS and Motor Neuron Disease Scientific Department of the Brazilian Academy of Neurology.
The spectrum of neuropsychiatric phenomena observed in amyotrophic lateral sclerosis (ALS) is wide and not fully understood. Disorders of laughter and crying stand among the most common manifestations. The aim of this study is to report the results of an educational consensus organized by the Brazilian Academy of Neurology to evaluate the definitions, phenomenology, diagnosis, and management of the disorders of laughter and crying in ALS patients. Twelve members of the Brazilian Academy of Neurology - considered to be experts in the field - were recruited to answer 12 questions about the subject. After exchanging revisions, a first draft was prepared. A face-to-face meeting was held in Fortaleza, Brazil on 9.23.22 to discuss it. The revised version was subsequently emailed to all members of the ALS Scientific Department from the Brazilian Academy of Neurology and the final revised version submitted for publication. The prevalence of pseudobulbar affect/pathological laughter and crying (PBA/PLC) in ALS patients from 15 combined studies and 3906 patients was 27.4% ( = 1070), ranging from 11.4% to 71%. Bulbar onset is a risk factor but there are limited studies evaluating the differences in prevalence among the different motor neuron diseases subtypes, including patients with and without frontotemporal dementia. Antidepressants and a combination of dextromethorphan and quinidine (not available in Brazil) are possible therapeutic options. This group of panelists acknowledge the multiple gaps in the current literature and reinforces the need for further studies.
Topics: Humans; Amyotrophic Lateral Sclerosis; Brazil; Laughter; Consensus; Crying; Motor Neuron Disease; Neurology
PubMed: 37647907
DOI: 10.1055/s-0043-1771176 -
The Journal of Clinical Psychiatry Aug 2023Among the greatest unmet needs in major depressive disorder (MDD) is a lack of effective pharmacotherapies for patients who do not respond to first- and second-line...
Among the greatest unmet needs in major depressive disorder (MDD) is a lack of effective pharmacotherapies for patients who do not respond to first- and second-line antidepressant medications. After decades of muted progress, optimism regarding the future of MDD therapy rose after scientists serendipitously uncovered the antidepressant effects of ketamine. The discovery of ketamine's antidepressant effects inspired the search for related newer medications, such as -ketamine. Orally administered NMDA antagonists have also demonstrated considerable promise in recently concluded, late-stage clinical trials. Researchers evaluating an extended-release combination of bupropion (105 mg) and dextromethorphan (45 mg) found that recipients experienced a decline in MADRS total score. Neurosteroids, such as brexanolone and zuranolone, appear to represent another class of antidepressants. These drugs appear to modulate GABA neurotransmission, which has long been known to be a pathway for drugs that are used to treat insomnia and anxiety. After nearly 50 years of legal injunctions against their use, psychedelic drugs have attracted interest among researchers seeking alternative antidepressants. Psilocybin, derived from mushrooms, remains under investigation for its benefits in treatment-resistant depression.
Topics: Humans; Depressive Disorder, Major; Ketamine; Antidepressive Agents; Hallucinogens; Depressive Disorder, Treatment-Resistant
PubMed: 37585245
DOI: 10.4088/JCP.mulmdd3048sho -
PloS One 2023The objection of this study was to investigate the effects of vindoline(VDL) on the cytochrome P450 (CYP 450) isoforms (CYP1A2, 2B, 2C11, 2D1 and 3A) in rats. Firstly,...
The objection of this study was to investigate the effects of vindoline(VDL) on the cytochrome P450 (CYP 450) isoforms (CYP1A2, 2B, 2C11, 2D1 and 3A) in rats. Firstly, the rats were randomly divided into VDL pretreatment group and blank group, each group had six rats. VDL pretreatment group was administrated VDL (20 mg·kg-1) by oral gavage for fifteen days consecutively, and the equivalent CMC-Na solution without VDL was given to the blank group by gavage. Secondly, a cocktail of caffeine, bupropion, diclofenac, dextromethorphan and midazolam was then administered on the sixteenth day. Finally, blood samples were collected at the specified time point, and the plasma concentration of the probe drug was determined by UHPLC-QTOF-MS/MS. The effects of VDL on the activity of these CYP enzymes in rats were evaluated by pharmacokinetic parameters. VDL pretreatment group compared with the blank group, accelerated the metabolism of diclofenac, and weakened the metabolism of caffeine. These results suggested that VDL could induce the activity of CYP2C11, and inhibits the activity of CYP1A2, but had no significant effects on CYP2B, CYP2D1 and CYP3A. The results in this study can provide beneficial information for the later clinical application of VDL.
Topics: Rats; Animals; Cytochrome P-450 CYP1A2; Catharanthus; Caffeine; Tandem Mass Spectrometry; Diclofenac; Cytochrome P-450 Enzyme System; Cytochrome P-450 CYP3A
PubMed: 37535556
DOI: 10.1371/journal.pone.0289656 -
Brain Stimulation 2023Transcranial ultrasound stimulation (TUS) is a novel non-invasive brain stimulation technique with high depth penetrance and spatial resolution. Theta-burst TUS (tbTUS)... (Randomized Controlled Trial)
Randomized Controlled Trial
BACKGROUND
Transcranial ultrasound stimulation (TUS) is a novel non-invasive brain stimulation technique with high depth penetrance and spatial resolution. Theta-burst TUS (tbTUS) is a plasticity-inducing protocol which increases motor cortical excitability for up to 30 min following 80s of sonication. While this protocol may have therapeutic potential for the treatment of psychiatric and neurological disorders, the mechanisms of action of TUS remain unclear.
OBJECTIVE
We conducted the first pharmacological study to examine the mechanisms of TUS in human primary motor cortex. By administering brain-active drugs with known mechanisms of action, we aimed to elucidate the mechanisms of tbTUS.
METHODS
Fourteen healthy subjects participated in a within-subjects randomized, double-blind, cross-over study with five visits. At each visit, one of four study drugs (carbamazepine - Na channel blocker, nimodipine - L-type Ca channel blocker, lorazepam - positive allosteric modulator of gamma-aminobutyric acid (GABA) type A receptor, dextromethorphan - N-methyl-d-aspartate receptor antagonist) or placebo was administered in random order, followed by tbTUS.
RESULTS
The plasticity effects of tbTUS on motor cortex excitability measured by motor-evoked potential amplitudes elicited by transcranial magnetic stimulation were reduced by all study drugs compared to placebo.
CONCLUSION
tbTUS may induce NMDA-dependent synaptic plasticity since the effects are blocked by increased GABA receptor activities and voltage-gated Na and Ca channels blockers. These results are consistent with the hypotheses that tbTUS induced long-term potentiation-like mechanisms and that TUS involves activation of mechanosensitive Na and Ca channels. Alternatively, non-specific pharmacologically induced changes in excitatory/inhibitory balance might have interfered with the effects of tbTUS.
Topics: Humans; Motor Cortex; Cross-Over Studies; Neuronal Plasticity; Long-Term Potentiation; Evoked Potentials, Motor; Transcranial Magnetic Stimulation
PubMed: 37524296
DOI: 10.1016/j.brs.2023.07.056 -
Urology Case Reports Sep 2023Both guaifenesin and dextromethorphan are routinely available nonprescription medications that are also common drugs of abuse amongst young adults. We describe a...
Both guaifenesin and dextromethorphan are routinely available nonprescription medications that are also common drugs of abuse amongst young adults. We describe a presentation of guaifenesin and dextromethorphan misuse resulting in acute renal failure due to bilateral nephrolithiasis. The patient underwent placement of bilateral ureteral stents but again formed small renal stones bilaterally. While most renal calculi are not drug-induced, this case highlights the potential for nephrolithiasis after guaifenesin and dextromethorphan ingestion. It suggests that in this combination ingestion multiple mechanisms lead to a prolonged period of nephrolith formation.
PubMed: 37455782
DOI: 10.1016/j.eucr.2023.102481 -
Molecular Metabolism Sep 2023Dextromethorphan (DXM) is a commonly used antitussive medication with positive effects in people with type 2 diabetes mellitus, since it increases glucose tolerance and...
OBJECTIVE
Dextromethorphan (DXM) is a commonly used antitussive medication with positive effects in people with type 2 diabetes mellitus, since it increases glucose tolerance and protects pancreatic islets from cell death. However, its use as an antidiabetic medication is limited due to its central nervous side effects and potential use as a recreational drug. Therefore, we recently modified DXM chemically to reduce its blood-brain barrier (BBB) penetration and central side effects. However, our best compound interacted with the cardiac potassium channel hERG (human ether-à-go-go-related gene product) and the μ-opioid receptor (MOR). Thus, the goal of this study was to reduce the interaction of our compound with these targets, while maintaining its beneficial properties.
METHODS
Receptor and channel binding assays were conducted to evaluate the drug safety of our DXM derivative. Pancreatic islets were used to investigate the effect of the compound on insulin secretion and islet cell survival. Via liquor collection from the brain and a behavioral assay, we analyzed the BBB permeability. By performing intraperitoneal and oral glucose tolerance tests as well as pharmacokinetic analyses, the antidiabetic potential and elimination half-life were investigated, respectively. To analyze the islet cell-protective effect, we used fluorescence microscopy as well as flow cytometric analyses.
RESULTS
Here, we report the design and synthesis of an optimized, orally available BBB-impermeable DXM derivative with lesser binding to hERG and MOR than previous ones. We also show that the new compound substantially enhances glucose-stimulated insulin secretion (GSIS) from mouse and human islets and glucose tolerance in mice as well as protects pancreatic islets from cell death induced by reactive oxygen species and that it amplifies the effects of tirzepatide on GSIS and islet cell viability.
CONCLUSIONS
We succeeded to design and synthesize a novel morphinan derivative that is BBB-impermeable, glucose-lowering and islet cell-protective and has good drug safety despite its morphinan and imidazole structures.
Topics: Mice; Humans; Animals; Diabetes Mellitus, Type 2; Insulin; Morphinans; Islets of Langerhans; Glucose; Hypoglycemic Agents; Oxidative Stress
PubMed: 37451343
DOI: 10.1016/j.molmet.2023.101775