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Cureus Apr 2024Stiff Person Syndrome (SPS) is a rare autoimmune condition marked by extremely painful muscle spasms, stiffness, and rigidity throughout the body. Its rarity often...
Stiff Person Syndrome (SPS) is a rare autoimmune condition marked by extremely painful muscle spasms, stiffness, and rigidity throughout the body. Its rarity often translates to limited treatment options for patients and, occasionally, challenges in obtaining a definitive diagnosis. SPS also impacts patients' mental health, social and economic involvement, and overall quality of life. A 43-year-old man was initially being seen for lumbar radicular pain. A clinical diagnosis of SPS was made by a neurologist and confirmed by in-clinic follow-ups and anti-glutamic acid decarboxylase (anti-GAD) antibody testing. The Pain Management doctor agreed with this diagnosis and offered intravenous (IV) ketamine treatment, which he has found to positively impact the treatment of similar disorders. After an initial 10-day infusion, the patient reported improvement in pain and function. For almost two years, the patient received intravenous immunoglobulin (IVIg) and IV ketamine treatments to manage their condition and maintain pain control as well as quality of life. When the patient's symptoms began worsening after IVIg infusions, the decision to withdraw IVIg infusions and continue ketamine infusions was made. After discontinuing IVIg infusions, the patient reported improvement in function and pain level and continues to receive monthly two-day ketamine boosters. Outside of the infusions, the patient was able to discontinue the use of fentanyl patches and continued taking ketamine lozenges, oxycodone-acetaminophen, and dextromethorphan for at-home pain management. The patient's symptoms continue to be managed effectively with their current regimen, enabling their return to work and experiencing an enhanced quality of life. This case illustrates the potential benefits of IV ketamine treatment for patients with treatment-resistant SPS and similar neurologic and autoimmune disorders. Understanding and examining treatment alternatives for rare syndromes is crucial for achieving optimal patient outcomes. Additionally, documenting such cases offers valuable insights into the mechanism of ketamine, extending beyond these syndromes.
PubMed: 38817534
DOI: 10.7759/cureus.59397 -
Biopharmaceutics & Drug Disposition Jun 2024The United States Food and Drug Administration guidelines for the bioequivalence (BE) testing of the generic drug products suggests that there should be an equal...
Evaluating gender effect in the generic bioequivalence studies by physiologically based pharmacokinetic modeling - A case study of dextromethorphan modified release tablets.
The United States Food and Drug Administration guidelines for the bioequivalence (BE) testing of the generic drug products suggests that there should be an equal proportion of male and female population in the BE study. Despite this requirement, many generic drug companies do not maintain the suggested proportion of female population in their studies. Several socio-economic and cultural factors lead to lower participation of the females in the BE studies. More recently, the regulatory agencies across the globe are requesting the generic drug companies to demonstrate the performance of their drug products in the under-represented sex via additional studies. In this work, we describe the case of Dextromethorphan modified release tablets where the gender effect on the product performance was evaluated by physiologically based pharmacokinetic (PBPK) modeling approach. We have compared the drug product's performance by population simulations considering four different scenarios. The data from all-male population (from in house Pharmacokinetic [PK] BE studies) was considered as a reference and other scenarios were compared against the all-male population data. In the first scenario, we made a comparison between all-male (100% male) vs all-female (100% female) population. Second scenario was as per agency's requirements-equal proportion of male and female in the BE study. As an extreme scenario, 100% male vs 30:70 male:female was considered (higher females than males in the BE studies). Finally, as a more realistic scenario, 100% male versus 70:30 male:female was considered (lower females than males in the BE studies). Population PK followed by virtual BE was employed to demonstrate the similarity/differences in the drug product performance between the sexes. This approach can be potentially utilized to seek BE study waivers thus saving cost and accelerating the entry of the generic products to the market.
Topics: Therapeutic Equivalency; Dextromethorphan; Humans; Male; Female; Drugs, Generic; Models, Biological; Tablets; Delayed-Action Preparations; Sex Factors; Adult
PubMed: 38776407
DOI: 10.1002/bdd.2389 -
Organic Letters May 2024()-1-(4-Methoxybenzyl)-1,2,3,4,5,6,7,8-octahydroisoquinoline (()-1-(4-methoxybenzyl)-OHIQ) is the key intermediate of the nonopioid antitussive dextromethorphan. In this...
()-1-(4-Methoxybenzyl)-1,2,3,4,5,6,7,8-octahydroisoquinoline (()-1-(4-methoxybenzyl)-OHIQ) is the key intermediate of the nonopioid antitussive dextromethorphan. In this study, ()-IR61-V69Y/P123A/W179G/F182I/L212V (M4) was identified with a 766-fold improvement in catalytic efficiency compared with wide-type IR61 through enzyme engineering. M4 could completely convert 200 mM of 1-(4-methoxybenzyl)-3,4,5,6,7,8-hexahydroisoquinoline into ()-1-(4-methoxybenzyl)-OHIQ in 77% isolated yield, with >99% enantiomeric excess and a high space-time yield of 542 g L day, demonstrating a great potential for the synthesis of dextromethorphan intermediate in industrial applications.
Topics: Dextromethorphan; Molecular Structure; Oxidoreductases; Imines; Stereoisomerism; Antitussive Agents; Protein Engineering
PubMed: 38747552
DOI: 10.1021/acs.orglett.4c01079 -
BMJ Supportive & Palliative Care May 2024
PubMed: 38744449
DOI: 10.1136/spcare-2024-004917 -
Turkish Journal of Pharmaceutical... May 2024The aim of this study was to develop a simple, accurate, and precise method for the estimation of bupropion and dextromethorphan in a fixed-dose combination of tablets...
OBJECTIVES
The aim of this study was to develop a simple, accurate, and precise method for the estimation of bupropion and dextromethorphan in a fixed-dose combination of tablets and robust high-performance liquid chromatography for assay analysis of such a fixed combination.
MATERIALS AND METHODS
Chromatographic analysis was performed and separations were achieved on a Denali C18 150 × 4.6 mm, 5 micron using a mobile phase composition of acid and acetonitrile in the ratio of 600:400 (), flow rate of 1.0 mL/min, injection volume is 10 µL and run time of 6 min in isocratic elution. Ultraviolet (UV) detection was performed at a wavelength of 221 nm. The temperature was maintained at 30 °C. Well-resolved peaks were observed with a high number of theoretical plates, lower tailing factor, and reproducible relative retention time. The method was validated, and all validation parameters were found to be within the acceptance limits.
RESULTS
A simple, accurate, and precise method has been developed for estimating bupropion and dextromethorphan in a fixed dose combination of tablets. The optimized method included the following parameters: column temperature of 30 °C, 40% acetonitrile as the mobile phase, and flow rate of 1.0 mL/min. Retention times were 2.25 min and 3.12 min for bupropion and dextromethorphan, respectively. The method was found to be linear in the range of 17.5-105 µg/mL [for R < 0.999) and 7.5-45 µg/mL (for R > 0.999] for bupropion and dextromethorphan, respectively. Both active pharmaceutical ingredients dissolved more than 90% within 5 min.
CONCLUSION
The current study describes a new, simple, reliable, and economical elution reversed-phase high performance liquid chromatography method for estimating bupropion and dextromethorphan in a fixed combination tablet dosage form. The forced degradation studies were conducted using several degradation conditions such as acidic, alkali, oxidation, thermal, UV, and neutral conditions; the proposed method was effectively employed from the resolution of sample peaks. To the best of our knowledge, no such detailed and stability-indicating method has been reported for a fixed tablet dosage form.
PubMed: 38742814
DOI: 10.4274/tjps.galenos.2023.87522 -
Analytical Methods : Advancing Methods... May 2024Dextromethorphan (DXM) is a widely utilized central antitussive agent, which is frequently abused by individuals seeking its recreational effect. But DXM overdose can...
Dextromethorphan (DXM) is a widely utilized central antitussive agent, which is frequently abused by individuals seeking its recreational effect. But DXM overdose can cause some adverse effects, including brain damage, loss of consciousness, and cardiac arrhythmias, and hence its detection is significant. Herein, an electrochemical sensor based on a Cu-coordinated molecularly imprinted polymer (Cu-MIP) was fabricated for its detection. For constructing the sensor, nitrogen-doped carbon nanosheets (CCNs) were prepared through calcining chitin under an argon atmosphere, and molybdenum disulfide (MoS) was allowed to grow on their surface. Subsequently, the obtained MoS/CCNs composite was employed to modify a glassy carbon electrode (GCE), and the Cu-MIP was electrodeposited on the electrode in a Cu-1,10-phenanthroline (Cu-Phen) solution containing DXM, where Cu played a role in facilitating electron transfer and binding DXM. Due to the large specific surface area, good electrocatalytic properties and recognition of the resulting composite, the resulting Cu-MIP/MoS/CCNs/GCE showed high selectivity and sensitivity. Under optimized experimental conditions, the peak current of DXM and its concentration exhibited a good linear relationship over the concentration range of 0.1-100 μM, and the limit of detection (S/N = 3) was 0.02 μM. Furthermore, the electrochemical sensor presented good stability, and it was successfully used for the determination of DXM in pharmaceutical, human serum and urine samples.
Topics: Molybdenum; Disulfides; Dextromethorphan; Copper; Electrochemical Techniques; Carbon; Molecularly Imprinted Polymers; Chitin; Humans; Limit of Detection; Electrodes; Antitussive Agents
PubMed: 38738557
DOI: 10.1039/d4ay00549j -
American Journal of Veterinary Research May 2024Develop a cytochrome P450 (CYP) phenotyping cocktail for dogs using specific substrates for hepatic P450 enzymes CYP2B11, CYP2D15, and CYP3A12 and determine whether...
OBJECTIVE
Develop a cytochrome P450 (CYP) phenotyping cocktail for dogs using specific substrates for hepatic P450 enzymes CYP2B11, CYP2D15, and CYP3A12 and determine whether alternative sampling methods (saliva and urine) or single time point samples could be used instead of multiple blood sampling.
ANIMALS
12 healthy client-owned dogs (8 females and 4 males) from February 2019 to May 2019.
METHODS
In a randomized crossover study, dogs received oral administration of the probe drug bupropion (75 mg), dextromethorphan (30 mg), or omeprazole (40 mg) alone or as a 3-drug combination (Program in Individualized Medicine [PrIMe] cocktail) to evaluate simultaneous phenotyping of CYP2B11, CYP2D15, and CYP3A12. Pharmacokinetic profiles for the probe drugs and metabolites were determined using plasma, saliva, and urine. Dogs received probe drugs alone or combined. Pharmacokinetic profiles up to 6 hours postdose for the probe drugs and metabolites were determined using plasma, saliva, and urine.
RESULTS
The PrIMe cocktail was well tolerated. There was no statistically significant interaction between the probe drugs when administered together. Single time point plasma metabolic ratios at 4 hours postdose for all probe drugs strongly correlated with the corresponding area under the plasma concentration-versus-time curve (AUC) ratios. Saliva AUC metabolic ratios for CYP3A12 and CYP2D15 and 6-hour urine for CYP2B11 and CYP2D15 were correlated with plasma AUC ratios.
CONCLUSIONS
The PrIMe cocktail can be used for simultaneous CYP phenotyping using plasma 4-hour single time point sample metabolic ratios. Saliva and urine sampling are suitable for specific CYPs.
CLINICAL RELEVANCE
The PrIMe cocktail has potential as a useful tool in dogs to detect clinically important CYP-mediated drug-drug interactions, identify novel pharmacogenes, determine the drug-metabolizing phenotype of individual dogs, aid in individualized dose selection, and evaluate the effects of various physiological states on drug metabolism.
PubMed: 38718826
DOI: 10.2460/ajvr.24.02.0049 -
Clinical and Translational Science May 2024St. John's wort (SJW) extract, a herbal medicine with antidepressant effects, is a potent inducer of intestinal and/or hepatic cytochrome P450 (CYP) enzymes and...
St. John's wort (SJW) extract, a herbal medicine with antidepressant effects, is a potent inducer of intestinal and/or hepatic cytochrome P450 (CYP) enzymes and P-glycoprotein (P-gp), which can cause clinically relevant drug interactions. It is currently not known whether SJW can also induce P-gp activity at the human blood-brain barrier (BBB), which may potentially lead to decreased brain exposure and efficacy of certain central nervous system (CNS)-targeted P-gp substrate drugs. In this study, we used a combination of positron emission tomography (PET) imaging and cocktail phenotyping to gain a comprehensive picture on the effect of SJW on central and peripheral P-gp and CYP activities. Before and after treatment of healthy volunteers (n = 10) with SJW extract with a high hyperforin content (3-6%) for 12-19 days (1800 mg/day), the activity of P-gp at the BBB was assessed by means of PET imaging with the P-gp substrate [C]metoclopramide and the activity of peripheral P-gp and CYPs was assessed by administering a low-dose phenotyping cocktail (caffeine, omeprazole, dextromethorphan, and midazolam or fexofenadine). SJW significantly increased peripheral P-gp, CYP3A, and CYP2C19 activity. Conversely, no significant changes in the peripheral metabolism, brain distribution, and P-gp-mediated efflux of [C]metoclopramide across the BBB were observed following the treatment with SJW extract. Our data suggest that SJW does not lead to significant P-gp induction at the human BBB despite its ability to induce peripheral P-gp and CYPs. Simultaneous intake of SJW with CNS-targeted P-gp substrate drugs is not expected to lead to P-gp-mediated drug interactions at the BBB.
Topics: Humans; Hypericum; Blood-Brain Barrier; Phloroglucinol; Plant Extracts; Male; Adult; Positron-Emission Tomography; Terpenes; Female; Young Adult; ATP Binding Cassette Transporter, Subfamily B, Member 1; ATP Binding Cassette Transporter, Subfamily B; Bridged Bicyclo Compounds; Terfenadine; Cytochrome P-450 Enzyme System; Healthy Volunteers
PubMed: 38700454
DOI: 10.1111/cts.13804 -
The Science of the Total Environment Jul 2024The misuse of antitussives preparations is a continuing problem in the world, and imply that they might have potential new psychoactive substances (NPS) activity....
The misuse of antitussives preparations is a continuing problem in the world, and imply that they might have potential new psychoactive substances (NPS) activity. However, few study focus on their ecological toxicity towards fish. In the present study, the machine learning (ML) methods gcForest and random forest (RF) were employed to predict NPS activity in 30 antitussives. The potential toxic target, mode of action (MOA), acute toxicity and chronic toxicity to fish were further investigated. The results showed that both gcForest and RF achieved optimal performance when utilizing combined features of molecular fingerprint (MF) and molecular descriptor (MD), with area under the curve (AUC) = 0.99, accuracy >0.94 and f1 score > 0.94, and were applied to screen the NPS activity in antitussives. A total of 15 antitussives exhibited potential NPS activity, including frequently-used substances like codeine and dextromethorphan. The binding affinity of these antitussives with zebrafish dopamine transporter (zDAT) was high, and even surpassing that of some traditional narcotics and NPS. Some antitussives formed hydrogen bonds or salt bridges with aspartate (Asp) 95, tyrosine (Tyr) 171 of zDAT. For the ecotoxicity, the MOA of these 15 antitussives in fish was predicted as narcosis. The prenoxdiazin, pholcodine, codeine, dextromethorphan and dextrorphan exhibited very toxic/toxic to fish. It was necessary to pay close attention to the ecotoxicity of these antitussives. In this study, the integration of ML, molecular docking and ECOSAR approaches are powerful tools for understanding the toxicity profiles and ecological hazards posed by new pollutants.
Topics: Animals; Water Pollutants, Chemical; Psychotropic Drugs; Zebrafish; Fishes; Machine Learning
PubMed: 38692322
DOI: 10.1016/j.scitotenv.2024.172872