Effects of green tea extracts on the pharmacokinetics of quetiapine in rats

From garden to madness: herbal products and psychotic experiences

Psychotic symptoms, characterized by hallucinations, delusions, and cognitive disturbances, are associated with various psychiatric and neurological disorders. This manuscript explores two cases of acute psychotic episodes triggered by the regular consumption of herbal products. The cases highlight the need for increased awareness of the potential toxic side effects of herbal products. The impact of herbal ingredients like maca and matcha on neurotransmitter activity is explored, shedding light on the underlying mechanisms leading to psychosis. The manuscript highlights the need to report both the benefits and risks of herbal products, challenging the misconception that they are inherently safe.

Changing Trends Towards Herbal Supplements: An Insight into Safety and Herb-drug Interaction

Herbs have been used as sustenance and medicine for a very long time, often in conjunction with other prescribed medications. Even though they are thought to be natural and secure, many of these herbs can interact with other medications and cause potentially dangerous adverse effects or decrease the benefits of the medication. The complex and diverse pharmacological functions carried out by the active ingredients in herbs unavoidably alter the pharmacokinetics of chemical drugs when administered in vivo. Drug transporter expression has a direct impact on how medications are absorbed, distributed, metabolized, and excreted in living organisms. Changes in substrate pharmacokinetics can affect the effectiveness and toxicity of a drug when the active ingredients of a herb inhibit or stimulate the expression of transporters. By reviewing published clinical and preclinical studies, this review aims to raise awareness of herbdrug interactions and discuss their evidence-based mechanisms and clinical consequences. More clinical information on herb-drug interactions is required to make choices regarding patient safety as the incidence and severity of herb-drug interactions are rising due to an increase in the use of herbal preparations globally.This review seeks to increase understanding of herb-drug interactions and explore their evidence-based mechanisms and clinical implications by reviewing published clinical and preclinical studies. The incidence and severity of herb-drug interactions are on the rise due to an increase in the use of herbal preparations worldwide, necessitating the need for more clinical data on these interactions in order to make decisions regarding patient safety. Healthcare workers and patients will become more alert to potential interactions as their knowledge of pharmacokinetic herb-drug interactions grows. The study's objective is to raise readers' awareness of possible interactions between herbal supplements and prescription medications who regularly take them.

Brain Targeting of Quetiapine Fumarate via Intranasal Delivery of Loaded Lipospheres: Fabrication, In-Vitro Evaluation, Optimization, and In-Vivo Assessment

A liposphere system for intranasal delivery of quetiapine fumarate (QTF) was created to assess the potential for enhanced drug delivery. We investigated the effects of particle size, entrapment effectiveness, poly dispersibility index, and pluronic incorporation percentage on these variables. The optimal formula was examined using a TEM, and investigations into DSC, XRD, and FTIR were made. Optimized liposphere formulation in vitro dissolution investigation with a mean diameter of 294.4 ± 18.2 nm revealed about 80% drug release in 6 h. The intranasal injection of QTF-loaded lipospheres showed a shorter T_max compared to that of intranasal and oral suspension, per the findings of an in vivo tissue distribution investigation in Wistar mice. Lipospheres were able to achieve higher drug transport efficiency (DTE %) and direct nose-to-brain drug transfer (DTP %). A potentially effective method for delivering QTF to specific brain regions is the liposphere system.

Central Composite Optimization of Glycerosomes for the Enhanced Oral Bioavailability and Brain Delivery of Quetiapine Fumarate

This study aimed to formulate and statistically optimize glycerosomal formulations of Quetiapine fumarate (QTF) to increase its oral bioavailability and enhance its brain delivery. The study was designed using a Central composite rotatable design using Design-Expert^® software. The independent variables in the study were glycerol % w/v and cholesterol % w/v, while the dependent variables were vesicle size (VS), zeta potential (ZP), and entrapment efficiency percent (EE%). The numerical optimization process resulted in an optimum formula composed of 29.645 (w/v%) glycerol, 0.8 (w/v%) cholesterol, and 5 (w/v%) lecithin. It showed a vesicle size of 290.4 nm, zeta potential of −34.58, and entrapment efficiency of 80.85%. The optimum formula was further characterized for DSC, XRD, TEM, in-vitro release, the effect of aging, and pharmacokinetic study. DSC thermogram confirmed the compatibility of the drug with the ingredients. XRD revealed the encapsulation of the drug in the glycerosomal nanovesicles. TEM image revealed spherical vesicles with no aggregates. Additionally, it showed enhanced drug release when compared to a drug suspension and also exhibited good stability for one month. Moreover, it showed higher brain C_max, AUC_0–24, and AUC_0–∞ and plasma AUC_0–24 and AUC_0–∞ in comparison to drug suspension. It showed brain and plasma bioavailability enhancement of 153.15 and 179.85%, respectively, compared to the drug suspension. So, the optimum glycerosomal formula may be regarded as a promising carrier to enhance the oral bioavailability and brain delivery of Quetiapine fumarate.

Effects of sedative psychotropic drugs combined with oxycodone on respiratory depression in the rat

Following a decision to require label warnings for concurrent use of opioids and benzodiazepines and increased risk of respiratory depression and death, the US Food and Drug Administratioin (FDA) recognized that other sedative psychotropic drugs may be substituted for benzodiazepines and be used concurrently with opioids. In some cases, data on the ability of these alternatives to depress respiration alone or in conjunction with an opioid are lacking. A nonclinical in vivo model was developed that could detect worsening respiratory depression when a benzodiazepine (diazepam) was used in combination with an opioid (oxycodone) compared to the opioid alone based on an increased arterial partial pressure of carbon dioxide (pCO2 ). The current study used that model to assess the impact on respiration of non-benzodiazepine sedative psychotropic drugs representative of different drug classes (clozapine, quetiapine, risperidone, zolpidem, trazodone, carisoprodol, cyclobenzaprine, mirtazapine, topiramate, paroxetine, duloxetine, ramelteon, and suvorexant) administered alone and with oxycodone. At clinically relevant exposures, paroxetine, trazodone, and quetiapine given with oxycodone significantly increased pCO2 above the oxycodone effect. Analyses indicated that most pCO2 interaction effects were due to pharmacokinetic interactions resulting in increased oxycodone exposure. Increased pCO2 recorded with oxycodone-paroxetine co-administration exceeded expected effects from only drug exposure suggesting another mechanism for the increased pharmacodynamic response. This study identified drug-drug interaction effects depressing respiration in an animal model when quetiapine or paroxetine were co-administered with oxycodone. Clinical pharmacodynamic drug interaction studies are being conducted with these drugs to assess translatability of these findings.

Inhibition effect of epigallocatechin-3-gallate on the pharmacokinetics of calcineurin inhibitors, tacrolimus, and cyclosporine A, in rats

BACKGROUND

Epigallocatechin-3-gallate (EGCG) is the most biologically active catechin of green tea. Tacrolimus (TAC) and cyclosporine A (CsA) are immunosuppressive agents commonly used in clinical organ transplantation. The present study investigated the effect of EGCG on the pharmacokinetics of TAC and CsA in rats and its underlying mechanisms.

RESEARCH DESIGN AND METHODS

Either TAC or CsA was administered to rats intravenously or orally with or without concomitant EGCG. Polymerase Chain Reaction and Western Blot were used to determine the effect of EGCG on drug-metabolizing enzymes (DMEs), drug transporters (DTs) and nuclear receptors (NRs).

RESULTS

The C_max and AUC of TAC were reduced, and V/F and CL/F of TAC were enhanced after co-administration of EGCG. EGCG increased the Cmax, AUC of CsA at 3 ~ 30 mg∙kg-1 dosages, while decreased those parameters at the dosage of 100 mg∙kg-1. EGCG inhibited the mRNA and protein expressions of DMEs and DTs, such as CYP3A1, A2, UGT1A1, Mdr1 and Mrp2, but upregulated the expressions of Car, Pxr and Fxr.

CONCLUSIONS

These results revealed consumption of high dose EGCG may cause a significant alteration in pharmacokinetics of TAC and distribution/elimination profiles of CsA through the regulation of DMEs, DTs and NRs.

Comparative Physicochemical and Pharmacokinetic Properties of Quetiapine and Its Active Metabolite Norquetiapine

Quetiapine (QTP) is an atypical antipsychotic drug commonly used to treat several psychiatric disorders and is metabolized into the active metabolite norquetiapine (NQTP). This study was designed to evaluate and compare the physicochemical properties, metabolic stability, brain distribution, and pharmacokinetics of QTP and NQTP. Compared to QTP, NQTP had a higher pK_a, solubility, and rat liver microsomal stability, optimal log D and similar log P values. For pharmacokinetic evaluation, QTP and NQTP were administered orally and intravenously to rats at various doses. The plasma QTP and NQTP concentrations in rats were determined by a fully-validated liquid-chromatography tandem mass spectrometry (LC-MS/MS). Over the investigated dosing range, both QTP and NQTP showed linear pharmacokinetics. Following oral administration of the same dose, the area under the concentration-time curve (AUC_0-∞) and maximum serum concentration (C_max) were larger after NQTP administration compared to QTP administration. In addition, NQTP had a greater absolute oral bioavailability compared to QTP (15.6% vs. 0.63%, respectively). The brain-to-plasma concentration ratio was greater after NQTP administration compared to the QTP and NQTP ratios after QTP administration. NQTP administration results in increased systemic exposure and brain distribution compared to QTP administration. Future studies are needed to evaluate the pharmacologic and toxicologic effects of increased NQTP exposures.