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Pharmaceuticals (Basel, Switzerland) Oct 2023Huntington's Disease (HD) is a severely debilitating neurodegenerative disorder in which sufferers exhibit different combinations of movement disorders, dementia, and... (Review)
Review
Huntington's Disease (HD) is a severely debilitating neurodegenerative disorder in which sufferers exhibit different combinations of movement disorders, dementia, and behavioral or psychiatric abnormalities. The disorder is a result of a trinucleotide repeat expansion mutation that is inherited in an autosomal dominant manner. While there is currently no treatment to alter the course of HD, there are medications that lessen abnormal movement and psychiatric symptoms. ClinicalTrials.gov was searched to identify drugs that are currently in or have completed phase III drug trials for the treatment of HD. The described phase III trials were further limited to interventional studies that were recruiting, active not recruiting, or completed. In addition, all studies must have posted an update within the past year. PubMed was used to gather further information on these interventional studies. Of the nine clinical trials that met these criteria, eight involved the following drugs: metformin, dextromethorphan/quinidine, deutetrabenazine, valbenazine, Cellavita HD, pridopidine, SAGE-718, and RO7234292 (RG6042). Of these drug treatments, four are already FDA approved. This systematic review provides a resource that summarizes the present therapies for treating this devastating condition that are currently in phase III clinical trials in the United States.
PubMed: 38004378
DOI: 10.3390/ph16111513 -
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 -
Frontiers in Pharmacology 2023Vortioxetine is a novel anti-major depression disorder drug with a high safety profile compared with other similar drugs. However, little research has been done on...
Vortioxetine is a novel anti-major depression disorder drug with a high safety profile compared with other similar drugs. However, little research has been done on drug-drug interactions (DDI) about vortioxetine. In this paper, the inhibitory effect of vortioxetine on cytochrome P450 (CYP450) and the type of inhibitory mechanism were investigated in human and rat liver microsomes. We set up an incubation system of 200 μL to measure the metabolism of probe substrates at the present of vortioxetine at 37°C. The concentrations of the metabolites of probe substrates were all measured by ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method. It was found no time-dependent inhibition (TDI) of vortioxetine through determination of half-maximal inhibitory concentration (IC) shift values. The enzymes and metabolites involved in this experiment in human and rats were as follows: CYP3A4/CYP3A (midazolam); CYP2B6/CYP2B (bupropion); CYP2D6/CYP2D (dextromethorphan); CYP2C8/CYP2C-1 (amodiaquine); CYP2C9/CYP2C-2 (losartan); and CYP2C19/CYP2C-3 (mephenytoin). We found that vortioxetine competitively inhibited CYP2C19 and CYP2D6 in human liver microsomes (HLMs) with inhibition constant (K) values of 2.17 μM and 9.37 μM, respectively. It was noncompetitive inhibition for CYP3A4 and CYP2C8, and its K values were 7.26 μM and 6.96 μM, respectively. For CYP2B6 and CYP2C9, vortioxetine exhibited the mixed inhibition with K values were 8.55 μM and 4.17 μM, respectively. In RLMs, the type of vortioxetine inhibition was uncompetitive for CYP3A and CYP2D (K = 4.41 and 100.9 μM). The inhibition type was competitive inhibition, including CYP2B and CYP2C-2 (K = 2.87 and 0.12 μM). The inhibition types of CYP2C-1 and CYP2C-3 (K = 39.91 and 4.23 μM) were mixed inhibition and noncompetitive inhibition, respectively. The study of the above mechanism will provide guidance for the safe clinical use of vortioxetine so that the occurrence of DDI can be avoided.
PubMed: 37790811
DOI: 10.3389/fphar.2023.1199548 -
Hospital Pharmacy Aug 2023Dextromethorphan is a distant derivative of morphine, used as an antitussive agent indicated in standard care for various infections and respiratory conditions ranging...
Dextromethorphan is a distant derivative of morphine, used as an antitussive agent indicated in standard care for various infections and respiratory conditions ranging from the common cold (rhinoviruses) to severe acute respiratory illness (SARI). Being a derivative of morphine, a natural central nervous system (CNS) depressant, dextromethorphan produces little to no action on CNS when ingested in the prescription dosage. We present a case of a 64-year-old female patient, a known case of ischemic heart disease post angioplasty and stenting to the left anterior descending artery (LAD), with heart failure with reduced ejection fraction (HFrEF), diabetes, hypertension, chronic kidney disease, and hypothyroidism who developed extrapyramidal symptoms post dextromethorphan administration. The incidence of dextromethorphan-induced dystonia is unknown, and the literature review suggests 4 case reports indicating dextromethorphan-induced dystonia, and each of those reports is a case of either accidental overdose or overdose in substance abuse disorder. No cases of these CNS side effects are described among adults with a therapeutic dose of dextromethorphan. This case report serves to sensitize the clinician about this rare occurrence.
PubMed: 37360212
DOI: 10.1177/00185787221150918 -
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 -
Expert Opinion on Emerging Drugs Jun 2024Agitation, psychosis, and apathy are prevalent and highly distressing neuropsychiatric symptoms (NPS) of Alzheimer's disease (AD) that have been linked to numerous... (Review)
Review
INTRODUCTION
Agitation, psychosis, and apathy are prevalent and highly distressing neuropsychiatric symptoms (NPS) of Alzheimer's disease (AD) that have been linked to numerous negative outcomes, including increased mortality, worsened cognitive decline, and caregiver burden. Current treatments for AD-associated agitation, namely atypical antipsychotics, provide some benefits but may increase the risk of serious adverse events and death. Meanwhile, no pharmacotherapies have been approved by regulatory agencies for the treatment of psychosis or apathy in AD. Over the past decade, many new and repurposed drugs have emerged as potential therapeutic options for managing these challenging NPS.
AREAS COVERED
This review aims to provide a comprehensive summary of pharmacotherapies that have recently been investigated in phase 2 and 3 clinical trials for the treatment of agitation, psychosis, or apathy in AD.
EXPERT OPINION
Novel atypical antipsychotics, serotonergic antidepressants, cannabinoids, and dextromethorphan combination drugs have shown promising results for alleviating agitation. Pimavanserin appears to be the most effective emerging therapy for psychosis, while methylphenidate has demonstrated good efficacy for apathy. Further research on biomarkers of NPS severity and treatment response, as well as continued improvements in methodological approaches are needed to advance the field.
PubMed: 38822731
DOI: 10.1080/14728214.2024.2363215 -
American Journal of TherapeuticsMajor depressive disorder (MDD) affects millions of people and is the leading cause of disability worldwide. Patients report decreased quality of life and ability to...
BACKGROUND
Major depressive disorder (MDD) affects millions of people and is the leading cause of disability worldwide. Patients report decreased quality of life and ability to perform activities of daily living. It is estimated that the current standard of care, which includes pharmacologic therapy with a selective serotonin reuptake inhibitor, is effective in 40%-60%. Additional treatment options are warranted. The combination of dextromethorphan (DEX) and bupropion (BUP) (Auveulty) was approved for treatment in 2022. This unique combination offers an interesting mechanism of action and favorable onset of action for patients with MDD.
PHARMACODYNAMICS AND PHARMACOKINETICS
The mechanism of action of DEX-BUP when used in combination is unique. DEX is a noncompetitive N-methyl-d-aspartate receptor antagonist rapidly metabolized through the CYP450 2D6. BUP is an aminoketone and CYP2D6 inhibitor, which results in increased plasma levels of DEX through competitive CYP2D6 inhibition.
CLINICAL TRIALS
In a phase 2 clinical study, the efficacy of DEX-BUP was compared with BUP alone in patients with clinically diagnosed MDD. At baseline, participants had moderate-to-severe depression using the Montgomery-Asberg Depression Rating Scale (MADRS) and Clinical Global Impressions Severity (CGI-S) scales. There was a significant overall reduction in MADRS and CGI-S scores in the treatment group compared with the BUP monotherapy with improvement observed as early as week 1 of treatment. Later, a phase 3 study was conducted comparing DEX-BUP 45 mg/105 mg with placebo in patients with moderate-to-severe MDD. Similarly, MADRS and CGI-S scores were significantly reduced in the treatment group. Adverse effects were similar in all groups.
THERAPEUTIC ADVANCE
Clinical response to first line treatment options for MDD are reported to be 40%-60%. Availability of additional treatment options, particularly those with reduced time to efficacy, may improve overall treatment and patient quality of life. DEX-BUP is a combination option that has been shown to improve depression symptoms as early as 1 week after initiation.
Topics: Humans; Depressive Disorder, Major; Bupropion; Dextromethorphan; Activities of Daily Living; Quality of Life
PubMed: 38231578
DOI: 10.1097/MJT.0000000000001699 -
Pediatric Pulmonology Aug 2023To determine objective and subjective endpoints most suitable for evaluating antitussive efficacy of dextromethorphan hydrobromide (DXM) in children. Spontaneous... (Randomized Controlled Trial)
Randomized Controlled Trial
OBJECTIVE
To determine objective and subjective endpoints most suitable for evaluating antitussive efficacy of dextromethorphan hydrobromide (DXM) in children. Spontaneous resolution of acute cough and large placebo effects are impediments to evaluating antitussive efficacy. Another impediment is paucity of age-appropriate, validated cough assessment tools.
METHODS
This was a multiple-dose, double-blind, placebo-controlled, randomized, pilot clinical study in children, aged 6-11 years, with cough due to the common cold. Eligible subjects met entry criteria and qualified by completing a run-in period where coughs were recorded with a cough monitor after they were dosed with sweet syrup. They were subsequently randomized to receive DXM or placebo over 4 days. Coughs were recorded during the initial 24 h; subjective assessments of cough severity and frequency were self-reported daily during treatment.
RESULTS
Data from 128 evaluable subjects (67 DXM; 61 placebo) were analyzed. Total coughs over 24-hours (primary endpoint) and cough frequency during daytime were reduced by 21.0% and 25.5%, respectively, with DXM relative to placebo. Also, greater reductions in cough severity and frequency were self-reported with DXM. These findings were statistically significant and medically relevant. No effects were detected between treatments for nighttime cough rates or impact of cough on sleep. Multiple doses of DXM and placebo were generally well-tolerated.
CONCLUSION
Evidence of DXM antitussive efficacy was shown in children using objective and subjective assessment tools validated in pediatric populations. Diurnal variation of cough frequency over 24 h reduced the assay sensitivity needed to detect treatment differences at nighttime, as coughs/hour decreased during sleep for both groups.
Topics: Child; Humans; Antitussive Agents; Cough; Dextromethorphan; Common Cold; Self Report; Double-Blind Method
PubMed: 37232330
DOI: 10.1002/ppul.26416 -
European Journal of Clinical... Jun 2024Linezolid is a commonly used antibiotic in the clinical treatment of gram-positive bacterial infections. The impacts of drug interactions on the pharmacokinetics of... (Review)
Review
OBJECTIVES
Linezolid is a commonly used antibiotic in the clinical treatment of gram-positive bacterial infections. The impacts of drug interactions on the pharmacokinetics of linezolid are often overlooked. This manuscript aims to review the medications that affect the pharmacokinetics of linezolid.
METHODS
In accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we queried the PubMed, Embase, and Cochrane Library for publications from database establishment to November 3, 2023, using the search terms: "Linezolid" and "interaction," or "interact," or "drug-drug interaction," or "co-treatment," or "cotreatment," or "combined," or "combination."
RESULTS
A total of 24 articles were included. Among the reported medication interactions, rifampicin, levothyroxine, venlafaxine, and phenobarbital could reduce the concentration of linezolid; clarithromycin, digoxin, cyclosporine, proton pump inhibitors, and amiodarone could increase the concentration of linezolid, while aztreonam, phenylpropanolamine, dextromethorphan, antioxidant vitamins, and magnesium-containing antacids had no significant effects on linezolid pharmacokinetics. The ratio of mean (ROM) of linezolid AUC in co-treatment with rifampicin to monotherapy was 0.67 (95%CI 0.58-0.77) and 0.63 (95%CI 0.43-0.91), respectively, in 2 studies, and co-treatment with 500 mg clarithromycin to monotherapy was 1.81 (95%CI 1.49-2.13).
CONCLUSIONS
This systematic review found that numerous drugs have an impact on the pharmacokinetics of linezolid, and the purported main mechanism may be that linezolid is the substrate of P-glycoprotein. In clinical practice, it is prudent to pay attention to the changes in linezolid pharmacokinetics caused by interactions. Conducting therapeutic drug monitoring (TDM) is beneficial to improve efficacy and reduce adverse reactions of linezolid.
Topics: Drug Interactions; Linezolid; Humans; Anti-Bacterial Agents
PubMed: 38421436
DOI: 10.1007/s00228-024-03652-2 -
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