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Investigating herb–drug interactions: the effect of Citrus aurantium fruit extract on the pharmacokinetics of amiodarone in rats

Rodrigues, Márcio; Alves, Gilberto; Falcão, Amílcar
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
86.26%
Citrus aurantium extract has been largely used in weight loss and sports performance dietary supplements. However, the safety of C. aurantium-containing products has been questioned mainly due to the association of its use with adverse events in the cardiovascular system. Therefore, this work aimed to assess the potential for herb–drug interactions among a standardized C. aurantium extract (GMP certificate) and amiodarone (narrow therapeutic index drug) in rats. In a first pharmacokinetic study, rats were simultaneously co-administered with a single-dose of C. aurantium (164 mg/kg, p.o.) and amiodarone (50 mg/kg, p.o.); in a second study, rats were pre-treated during 14 days with C. aurantium (164 mg/kg/day, p.o.) and received amiodarone (50 mg/kg, p.o.) on the 15th day. Rats of the control groups received the corresponding volume of vehicle. Overall, after analysis of the pharmacokinetic data, it deserves to be highlighted the significant increase of the peak plasma concentration of amiodarone in rats pre-treated with C. aurantium extract, while the extent of systemic exposure was comparable between both groups. This paper reports, for the first time, data on the potential of herb–drug interaction between C. aurantium extract and amiodarone. However...

Fitoterápicos e potenciais interações medicamentosas na terapia do câncer; Possible herb-drug interactions in cancer treatment

FUKUMASU, Heidge; LATORRE, Andréia Oliveira; BRACCI, Natália; GÓRNIAK, Silvana Lima; DAGLI, Maria Lúcia Zaidan
Fonte: Sociedade Brasileira de Toxicologia; São Paulo Publicador: Sociedade Brasileira de Toxicologia; São Paulo
Tipo: Artigo de Revista Científica
POR
Relevância na Pesquisa
96.39%
Atualmente o tratamento dos cânceres, em sua grande maioria, é considerado como um dos problemas mais desafiadores da medicina. A partir do momento que a neoplasia primária metastatiza pelo corpo do hospedeiro o prognóstico se torna extremamente ruim, sendo a quimioterapia antineoplásica a principal forma de tratamento neste estágio. Uma vantagem deste tratamento é o de atingir as metástases disseminadas pelo corpo. Entretanto, há desvantagens importantes a serem consideradas principalmente aquelas relacionadas aos seus efeitos colaterais, pois em sua grande maioria estes medicamentos apresentam baixo índice terapêutico, ou seja, dose terapêutica muito próxima a dose tóxica. Por outro lado. vários fitoterápicos têm surgido com o propósito de tratar câncer, aumentando seu consumo no mundo ocidental. Embora algumas destas plantas tenham apresentado efeitos antineoplásicos em estudos pré-clínicos, é importante ressaltar que quando consumidas simultaneamente com os medicamentos convencionais prescritos podem causar intoxicações devido à interações medicamentosas. Desta maneira, o objetivo desta revisão alertar que o consumo destas formulações à base de plantas em conjunto com quimioterápicos antineoplásicos pode acarretar em interações medicamentosas...

Simultaneous interstitial pneumonitis and cardiomyopathy induced by venlafaxine

Ferreira,Pedro Gonçalo; Costa,Susana; Dias,Nuno; Ferreira,António Jorge; Franco,Fátima
Fonte: Sociedade Brasileira de Pneumologia e Tisiologia Publicador: Sociedade Brasileira de Pneumologia e Tisiologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2014 EN
Relevância na Pesquisa
66.14%
Venlafaxine is a serotonin-norepinephrine reuptake inhibitor used as an antidepressant. Interindividual variability and herb-drug interactions can lead to drug-induced toxicity. We report the case of a 35-year-old female patient diagnosed with synchronous pneumonitis and acute cardiomyopathy attributed to venlafaxine. The patient sought medical attention due to dyspnea and dry cough that started three months after initiating treatment with venlafaxine for depression. The patient was concomitantly taking Centella asiatica and Fucus vesiculosus as phytotherapeutic agents. Chest CT angiography and chest X-ray revealed parenchymal lung disease (diffuse micronodules and focal ground-glass opacities) and simultaneous dilated cardiomyopathy. Ecocardiography revealed a left ventricular ejection fraction (LVEF) of 21%. A thorough investigation was carried out, including BAL, imaging studies, autoimmune testing, right heart catheterization, and myocardial biopsy. After excluding other etiologies and applying the Naranjo Adverse Drug Reaction Probability Scale, a diagnosis of synchronous pneumonitis/cardiomyopathy associated with venlafaxine was assumed. The herbal supplements taken by the patient have a known potential to inhibit cytochrome P450 enzyme complex...

Clinical risk management of herb–drug interactions

De Smet, Peter A G M
Fonte: Blackwell Science Inc Publicador: Blackwell Science Inc
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
66.23%
The concomitant use of conventional and herbal medicines can lead to clinically relevant herb–drug interactions. Clinical risk management offers a systematic approach to minimize the untoward consequences of these interactions by paying attention to: (i) risk identification and assessment; (ii) development and execution of risk reduction strategies; and (iii) evaluation of risk reduction strategies. This paper reviews which steps should be explored or taken in these domains to improve the clinical risk management of adverse herb–drug interactions.

Evaluation of Chinese-Herbal-Medicine-Induced Herb-Drug Interactions: Focusing on Organic Anion Transporter 1

Lin, Chang-Ching; Fan, Hsien-Yuan; Kuo, Chien-Wen; Pao, Li-Heng
Fonte: Hindawi Publishing Corporation Publicador: Hindawi Publishing Corporation
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
66.27%
The consumption of Chinese herbal medicines (CHMs) is increasing exponentially. Many patients utilize CHMs concomitantly with prescription drugs in great frequency. Herb-drug interaction has hence become an important focus of study. Transporter-mediated herb-drug interactions have the potential to seriously influence drug efficacy and toxicity. Since organic anion transporter 1 (OAT1) is crucial in renal active secretion and drug-drug interactions, the possibility of modulation of OAT1-mediated drug transport should be seriously concerned. Sixty-three clinically used CHMs were evaluated in the study. An hOAT1-overexpressing cell line was used for the in vitro CHMs screening, and the effective candidates were administered to Wistar rats to access renal hemodynamics. The regulation of OAT1 mRNA expression was also examined for further evidence of CHMs affecting OAT1-mediated transport. Among all the 63 CHMs, formulae Gui Zhi Fu Ling Wan (GZ) and Chia Wei Hsiao Yao San (CW) exhibited significant inhibitions on hOAT1-mediated [3H]-PAH uptake in vitro and PAH clearance and net secretion in vivo. Moreover, GZ showed concentration-dependent manners both in vitro and in vivo, and the decrease of rOAT1 mRNA expression indicated that GZ not only inhibited function of OAT1 but also suppressed expression of OAT1.

Investigation of herb-drug interactions with ginkgo biloba in women receiving hormonal treatment for early breast cancer

Vardy, Janette; Dhillon, Haryana M; Clarke, Stephen J; Olesen, Inger; Leslie, Felicity; Warby, Anne; Beith, Jane; Sullivan, Anne; Hamilton, Anne; Beale, Philip; Rittau, Anneliese; McLachlan, Andrew J
Fonte: Springer International Publishing AG Publicador: Springer International Publishing AG
Tipo: Artigo de Revista Científica
Publicado em 22/03/2013 EN
Relevância na Pesquisa
66.06%
Women receiving treatment for breast cancer commonly ingest herbal medicines. Little is known about the potential for herb-drug interactions in this population. The aim of this study is to investigate the effect of ginkgo biloba co-administration on the pharmacokinetics of tamoxifen, anastrozole and letrozole. This was a prospective open-label cross-over study in 60 women with early stage breast cancer taking either tamoxifen, anastrozole or letrozole (n=20/group). Participants received ginkgo biloba (EGb 761) for 3 weeks (120 mg twice daily). Trough concentrations of drugs were measured before and after ginkgo biloba treatment using LC-MS/MS. Toxicities were graded according to National Cancer Institute Common Terminology Criteria for Adverse Events. Trough concentrations before and after treatment with ginkgo biloba were not significantly different for tamoxifen (93.5 ± 29.0, 86.5 ± 25.3 ng/mL; p=0.16), letrozole (91.1 ± 50.4, 89.6 ± 52.14 ng/mL; p=0.60) or anastrozole (29.1 ± 8.6, 29.1 ± 7.6 ng/mL; p=0.97). Ginkgo biloba was well tolerated, with no difference in toxicity during ginkgo biloba. Co-administration of ginkgo biloba does not significantly affect the pharmacokinetics of tamoxifen, anastrozole or letrozole. There was no difference in the toxicity profile of hormone therapy with ginkgo biloba use in women with early stage breast cancer.

The Evaluation of CP-001 (a Standardized Herbal Mixture of Houttuynia cordata, Rehmannia glutinosa, Betula platyphylla, and Rubus coreanus) for Cytochrome P450-Related Herb-Drug Interactions

Yoo, Hye Hyun; Kim, Sun-A; Kim, In Sook; Ko, Seong-Gyu
Fonte: Hindawi Publishing Corporation Publicador: Hindawi Publishing Corporation
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
66.12%
In the present study, the effect of CP-001, a standardized herbal mixture of Houttuynia cordata, Rehmannia glutinosa, Betula platyphylla, and Rubus coreanus, on cytochrome P450 (CYP) enzyme-mediated drug metabolism was investigated in vitro to evaluate the potential for herb-drug interactions. CP-001 was tested at concentrations of 1, 3, 10, 30, and 100 μg/mL. A CYP-specific substrate mixture was incubated with CP-001 in human liver microsomes, and the metabolites generated by each CYP-specific metabolic reaction were measured by liquid chromatography-tandem mass spectrometry. CP-001 seemed to slightly inhibit some CYP isozymes, but the IC50 values for all CYP isozymes were greater than 100 μg/mL. Furthermore, CP-001 did not exhibit time-dependent CYP inhibitory activities, indicating that it does not act as a mechanism-based inactivator of CYP enzymes. In conclusion, the effects of CP-001 on CYP isozyme activities were negligible at the concentrations tested. Therefore, the likelihood of herbal mixture-drug interaction is considered minimal.

A Systematic Approach to Evaluate Herb-Drug Interaction Mechanisms: Investigation of Milk Thistle Extracts and Eight Isolated Constituents as CYP3A Inhibitors

Brantley, Scott J.; Graf, Tyler N.; Oberlies, Nicholas H.; Paine, Mary F.
Fonte: The American Society for Pharmacology and Experimental Therapeutics Publicador: The American Society for Pharmacology and Experimental Therapeutics
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
56.25%
Despite increasing recognition of potential untoward interactions between herbal products and conventional medications, a standard system for prospective assessment of these interactions remains elusive. This information gap was addressed by evaluating the drug interaction liability of the model herbal product milk thistle (Silybum marianum) with the CYP3A probe substrate midazolam. The inhibitory effects of commercially available milk thistle extracts and isolated constituents on midazolam 1′-hydroxylation were screened using human liver and intestinal microsomes. Relative to vehicle, the extract silymarin and constituents silybin A, isosilybin A, isosilybin B, and silychristin at 100 μM demonstrated >50% inhibition of CYP3A activity with at least one microsomal preparation, prompting IC50 determination. The IC50s for isosilybin B and silychristin were ∼60 and 90 μM, respectively, whereas those for the remaining constituents were >100 μM. Extracts and constituents that contained the 1,4-dioxane moiety demonstrated a >1.5-fold shift in IC50 when tested as potential mechanism-based inhibitors. The semipurified extract, silibinin, and the two associated constituents (silybin A and silybin B) demonstrated mechanism-based inhibition of recombinant CYP3A4 (KI...

Herb–Drug Interactions: Challenges and Opportunities for Improved Predictions

Brantley, Scott J.; Argikar, Aneesh A.; Lin, Yvonne S.; Nagar, Swati; Paine, Mary F.
Fonte: The American Society for Pharmacology and Experimental Therapeutics Publicador: The American Society for Pharmacology and Experimental Therapeutics
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
66.37%
Supported by a usage history that predates written records and the perception that “natural” ensures safety, herbal products have increasingly been incorporated into Western health care. Consumers often self-administer these products concomitantly with conventional medications without informing their health care provider(s). Such herb–drug combinations can produce untoward effects when the herbal product perturbs the activity of drug metabolizing enzymes and/or transporters. Despite increasing recognition of these types of herb–drug interactions, a standard system for interaction prediction and evaluation is nonexistent. Consequently, the mechanisms underlying herb–drug interactions remain an understudied area of pharmacotherapy. Evaluation of herbal product interaction liability is challenging due to variability in herbal product composition, uncertainty of the causative constituents, and often scant knowledge of causative constituent pharmacokinetics. These limitations are confounded further by the varying perspectives concerning herbal product regulation. Systematic evaluation of herbal product drug interaction liability, as is routine for new drugs under development, necessitates identifying individual constituents from herbal products and characterizing the interaction potential of such constituents. Integration of this information into in silico models that estimate the pharmacokinetics of individual constituents should facilitate prospective identification of herb–drug interactions. These concepts are highlighted with the exemplar herbal products milk thistle and resveratrol. Implementation of this methodology should help provide definitive information to both consumers and clinicians about the risk of adding herbal products to conventional pharmacotherapeutic regimens.

Physiologically Based Pharmacokinetic Modeling Framework for Quantitative Prediction of an Herb–Drug Interaction

Brantley, S J; Gufford, B T; Dua, R; Fediuk, D J; Graf, T N; Scarlett, Y V; Frederick, K S; Fisher, M B; Oberlies, N H; Paine, M F
Fonte: Nature Publishing Group Publicador: Nature Publishing Group
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
56.3%
Herb–drug interaction predictions remain challenging. Physiologically based pharmacokinetic (PBPK) modeling was used to improve prediction accuracy of potential herb–drug interactions using the semipurified milk thistle preparation, silibinin, as an exemplar herbal product. Interactions between silibinin constituents and the probe substrates warfarin (CYP2C9) and midazolam (CYP3A) were simulated. A low silibinin dose (160 mg/day × 14 days) was predicted to increase midazolam area under the curve (AUC) by 1%, which was corroborated with external data; a higher dose (1,650 mg/day × 7 days) was predicted to increase midazolam and (S)-warfarin AUC by 5% and 4%, respectively. A proof-of-concept clinical study confirmed minimal interaction between high-dose silibinin and both midazolam and (S)-warfarin (9 and 13% increase in AUC, respectively). Unexpectedly, (R)-warfarin AUC decreased (by 15%), but this is unlikely to be clinically important. Application of this PBPK modeling framework to other herb–drug interactions could facilitate development of guidelines for quantitative prediction of clinically relevant interactions.

Herbal medicines in Brazil: pharmacokinetic profile and potential herb-drug interactions

Mazzari, Andre L. D. A.; Prieto, Jose M.
Fonte: Frontiers Media S.A. Publicador: Frontiers Media S.A.
Tipo: Artigo de Revista Científica
Publicado em 09/07/2014 EN
Relevância na Pesquisa
66.34%
A plethora of active compounds found in herbal medicines can serve as substrate for enzymes involved in the metabolism of xenobiotics. When a medicinal plant is co-administered with a conventional drug and little or no information is known about the pharmacokinetics of the plant metabolites, there is an increased risk of potential herb-drug interactions. Moreover, genetic polymorphisms in a population may act to predispose individuals to adverse reactions. The use of herbal medicines is rapidly increasing in many countries, particularly Brazil where the vast biodiversity is a potential source of new and more affordable treatments for numerous conditions. Accordingly, the Brazilian Unified Public Health System (SUS) produced a list of 71 plant species of interest, which could be made available to the population in the near future. Physicians at SUS prescribe a number of essential drugs and should herbal medicines be added to this system the chance of herb-drug interactions further increases. A review of the effects of these medicinal plants on Phase 1 and Phase 2 metabolic mechanisms and the transporter P-glycoprotein was conducted. The results have shown that approximately half of these medicinal plants lack any pharmacokinetic data. Moreover...

Inhibition of Major Drug Metabolizing CYPs by Common Herbal Medicines used by HIV/AIDS Patients in Africa– Implications for Herb-Drug Interactions

Awortwe, Charles; Bouic, Patrick J.; Masimirembwa, Collen M.; Rosenkranz, Bernd
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /07/2014 EN
Relevância na Pesquisa
66.1%
The purpose of this study was to evaluate the potential risk of common herbal medicines used by HIV-infected patients in Africa for herb-drug interactions (HDI). High throughput screening assays consisting of recombinant Cytochrome P450 enzymes (CYPs) and fluorescent probes, and parallel artificial membrane permeability assays (PAMPA) were used. The potential of herbal medicines to cause HDI was ranked according to FDA guidelines for reversible inhibition and categorization of time dependent inhibition was based on the normalized ratio. CYPs 1A2 and 3A4 were most inhibited by the herbal extracts. H. hemerocallidea (IC50 = 0.63 μg/mL and 58 μg/mL) and E. purpurea (IC50 = 20 μg/mL and 12 μg/mL) were the potent inhibitors of CYPs 1A2 and 3A4 respectively. L. frutescens and H. hemerocallidea showed clear time dependent inhibition on CYP3A4. Furthermore, the inhibitory effect of both H. hemerocallidea and L. frutescens before and after PAMPA were identical. The results indicate potential HDI of H. hemerocallidea, L. frutescens and E. purpurea with substrates of the affected enzymes if maximum in vivo concentration is achieved.

Application of Caco-2 Cell Line in Herb-Drug Interaction Studies: Current Approaches and Challenges

Awortwe, C.; Fasinu, P.S.; Rosenkranz, B.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em //2014 EN
Relevância na Pesquisa
56.32%
The Caco-2 model is employed in pre-clinical investigations to predict the likely gastrointestinal permeability of drugs because it expresses cytochrome P450 enzymes, transporters, microvilli and enterocytes of identical characteristics to the human small intestine. The FDA recommends this model as integral component of the Biopharmaceutics Classification System (BCS). Most dedicated laboratories use the Caco-2 cell line to screen new chemical entities through prediction of its solubility, bioavailability and the possibility of drug-drug or herb-drug interactions in the gut lumen. However, challenges in the inherent characteristics of Caco-2 cell and inter-laboratory protocol variations have resulted to generation of irreproducible data. These limitations affect the extrapolation of data from pre-clinical research to clinical studies involving drug-drug and herb-drug interactions. This review addresses some of these caveats and enumerates the plausible current and future approaches to reduce the anomalies associated with Caco-2 cell line investigations focusing on its application in herb-drug interactions.

Pharmacogenomics and Herb-Drug Interactions: Merge of Future and Tradition

Liu, Mou-Ze; Zhang, Yue-Li; Zeng, Mei-Zi; He, Fa-Zhong; Luo, Zhi-Ying; Luo, Jian-Quan; Wen, Jia-Gen; Chen, Xiao-Ping; Zhou, Hong-Hao; Zhang, Wei
Fonte: Hindawi Publishing Corporation Publicador: Hindawi Publishing Corporation
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
66.35%
The worldwide using of herb products and the increasing potential herb-drug interaction issue has raised enthusiasm on discovering the underlying mechanisms. Previous review indicated that the interactions may be mediated by metabolism enzymes and transporters in pharmacokinetic pathways. On the other hand, an increasing number of studies found that genetic variations showed some influence on herb-drug interaction effects whereas these genetic factors did not draw much attention in history. We highlight that pharmacogenomics may involve the pharmacokinetic or pharmacodynamic pathways to affect herb-drug interaction. We are here to make an updated review focused on some common herb-drug interactions in association with genetic variations, with the aim to help safe use of herbal medicines in different individuals in the clinic.

Potential herb-drug interactions found in a community pharmacy patients; Potenciais interações plantas - medicamentos encontradas em utentes de uma farmácia comunitária

Batista, C.; Pinho, C.; Castel-Branco, M.; Caramona, M.; Figueiredo, I.
Fonte: Edições Universitárias Lusófonas Publicador: Edições Universitárias Lusófonas
Tipo: Artigo de Revista Científica
ENG; POR
Relevância na Pesquisa
86.27%
Phytotherapy has always played a leading role in therapeutics. However, a strong knowledge of the risk-benefit relationship of herbal products by patients and health professionals is necessary. The goals of this study were to characterize the consumption pattern of medicinal plants in patients in a community pharmacy, identify potential herb-drug interactions, and establish a list of recommendations for health professionals and/or patients in order to prevent/minimize negative outcomes arising from these interactions. In a sample of 25 patients, 24 cases of potential herb-drug interactions were detected. Most of the cases corresponded to the simultaneous use of a conventional medication with Ginkgo. The recommendation list involved monitoring the effectiveness and safety of conventional therapy associated with the use of medicinal plants, with particular focus on clinical and laboratory monitoring of the occurrence of bleeding, blood pressure, glycaemia and liver function. The results indicate that there is still a lack of knowledge about the possible risks of herbal products, which may adversely affect patient’s health. The pharmacist is in prime position to raise awareness in the population, avoiding harmful situations for the patient's health.; A fitoterapia desempenha um papel preponderante ao nível da terapêutica. Mas só um forte conhecimento da relação benefício-risco dos produtos à base de plantas...

Screening Ingredients from Herbs against Pregnane X Receptor in the Study of Inductive Herb-Drug Interactions: Combining Pharmacophore and Docking-Based Rank Aggregation

Cui, Zhijie; Kang, Hong; Tang, Kailin; Liu, Qi; Cao, Zhiwei; Zhu, Ruixin
Fonte: Hindawi Publishing Corporation Publicador: Hindawi Publishing Corporation
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
66.51%
The issue of herb-drug interactions has been widely reported. Herbal ingredients can activate nuclear receptors and further induce the gene expression alteration of drug-metabolizing enzyme and/or transporter. Therefore, the herb-drug interaction will happen when the herbs and drugs are coadministered. This kind of interaction is called inductive herb-drug interactions. Pregnane X Receptor (PXR) and drug-metabolizing target genes are involved in most of inductive herb-drug interactions. To predict this kind of herb-drug interaction, the protocol could be simplified to only screen agonists of PXR from herbs because the relations of drugs with their metabolizing enzymes are well studied. Here, a combinational in silico strategy of pharmacophore modelling and docking-based rank aggregation (DRA) was employed to identify PXR's agonists. Firstly, 305 ingredients were screened out from 820 ingredients as candidate agonists of PXR with our pharmacophore model. Secondly, DRA was used to rerank the result of pharmacophore filtering. To validate our prediction, a curated herb-drug interaction database was built, which recorded 380 herb-drug interactions. Finally, among the top 10 herb ingredients from the ranking list, 6 ingredients were reported to involve in herb-drug interactions. The accuracy of our method is higher than other traditional methods. The strategy could be extended to studies on other inductive herb-drug interactions.

Clinical assessment of CYP2D6-mediated herb-drug interactions in humans: Effects of milk thistle, black cohosh, goldenseal, kava kava, St. John's wort, and Echinacea

Gurley, Bill J.; Swain, Ashley; Hubbard, Martha A.; Williams, D. Keith; Barone, Gary; Hartsfield, Faith; Tong, Yudong; Carrier, Danielle J.; Cheboyina, Shreekar; Battu, Sunil K.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /07/2008 EN
Relevância na Pesquisa
66.15%
Cytochrome P450 2D6 (CYP2D6), an important CYP isoform with regard to drug-drug interactions, accounts for the metabolism of ∼30% of all medications. To date, few studies have assessed the effects of botanical supplementation on human CYP2D6 activity in vivo. Six botanical extracts were evaluated in three separate studies (2 extracts per study), each incorporating 18 healthy volunteers (9 females). Subjects were randomized to receive a standardized botanical extract for 14 days on separate occasions. A 30-day washout period was interposed between each supplementation phase. In study 1, subjects received milk thistle (Silybum marianum) and black cohosh (Cimicifuga racemosa). In study 2, kava kava (Piper methysticum), and goldenseal (Hydrastis canadensis) extracts were administered, and in study 3 subjects received St. John's wort (Hypericum perforatum) and Echinacea (Echinacea purpurea). The CYP2D6 substrate, debrisoquine (5 mg), was administered before and at the end of supplementation. Pre- and post-supplementation phenotypic trait measurements were determined for CYP2D6 using 8-hour debrisoquine urinary recovery ratios (DURR). Comparisons of pre- and post-supplementation DURR revealed significant inhibition (∼50%) of CYP2D6 activity for goldenseal...

Gauging the clinical significance of P-glycoprotein-mediated herb-drug interactions: Comparative effects of St. John's wort, echinacea, clarithromycin, and rifampin on digoxin pharmacokinetics

Gurley, Bill J.; Swain, Ashley; Williams, D. Keith; Barone, Gary; Battu, Sunil Kumar
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /07/2008 EN
Relevância na Pesquisa
66.21%
Concomitant administration of botanical supplements with drugs that are P-glycoprotein (P-gp) substrates may produce clinically significant herb-drug interactions. This study evaluated the effects of St. John's wort and Echinacea on the pharmacokinetics of digoxin, a recognized P-gp substrate. Eighteen healthy volunteers were randomly assigned to receive a standardized St. John's wort (300 mg three times daily) or Echinacea (267 mg three times daily) supplement for 14 days, followed by a 30-day washout period. Subjects were also randomized to receive rifampin (300 mg twice daily, 7 days) and clarithromycin (500 mg twice daily, 7 days) as positive controls for P-gp induction and inhibition, respectively. Digoxin (Lanoxin® 0.25 mg) was administered orally before and after each supplementation and control period. Serial digoxin plasma concentrations were obtained over 24 hours and analyzed by chemiluminescent immunoassay. Comparisons of AUC(0-3), AUC(0-24), T1/2, and Cmax, were used to assess the effects of St. John's wort, Echinacea, rifampin, and clarithromycin on digoxin disposition. St. John's wort and rifampin both produced significant reductions (p<0.05) in AUC(0-3), AUC(0-24), and Cmax, while clarithromycin increased these parameters significantly (p<0.05). Echinacea supplementation did not affect digoxin pharmacokinetics. Clinically significant P-gp-mediated herb-drug interactions are more likely to occur with St. John's wort than with Echinacea.

Herb-drug interactions among commonly used psychoactive substances by healthcare students

Coelho, André; Caetano, Liliana Aranha
Fonte: Instituto Politécnico de Lisboa Publicador: Instituto Politécnico de Lisboa
Tipo: Conferência ou Objeto de Conferência
Publicado em /05/2014 POR
Relevância na Pesquisa
96.25%
The concurrent use of herbs and/or nutritional supplements with psychoactive effect and prescription medications is common among college students. College students are a particularly vulnerable population, for they are under less social/familiar surveillance and seek greater independence, as well as under greater intellectual effort, stress, anxiety and depression, which predispose them to a higher consumption of psychoactive substances. Herbs, vitamins, and other dietary supplements may influence the effects of prescription and nonprescription drugs leading to adverse consequences, by increasing the potential for interactions. However, documented interactions between herbal medicinal products and prescribed drugs are rare. Objective: determine the prevalence of concomitant use of psychoactive substances among healthcare students in the Lisbon School of Health Technology, Portugal, in order to assess the risk of potential herb-drug interactions.

Herbal medicines supplied by community pharmacies in Lagos, Nigeria: pharmacists´ knowledge

Oshikoya,Kazeem A.; Oreagba,Ibrahim A.; Ogunleye,Olayinka O.; Oluwa,Rashidat; Senbanjo,Idowu O.; Olayemi,Sunday O.
Fonte: Pharmacy Practice (Internet) Publicador: Pharmacy Practice (Internet)
Tipo: info:eu-repo/semantics/article; journal article; info:eu-repo/semantics/publishedVersion Formato: text/html; application/pdf
Publicado em 01/12/2013 ENG
Relevância na Pesquisa
66.21%
Background: The use of herbal medicines is on the increase globally and they are usually supplied in pharmacies as non-prescription medicines. Pharmacists are, therefore, responsible for educating and informing the consumers about rational use of herbal medicines. Objectives: To evaluate the knowledge of pharmacists in Lagos, Nigeria with regards to the herbal medicines they supplied by their pharmacies. Methods: Pharmacists in charge of randomly selected 140 community pharmacies from 20 Local Government Areas in Lagos were required to fill out a self-administered questionnaire. We gathered information on their knowledge of the indications, adverse effects, potential drug-herb interactions and contraindications of the herbal medicines they supply in their pharmacies. Results: Of the 140 questionnaires distributed, 103 (72.9%) participants completed the questionnaire appropriately. The majority (74; 71.8%) of the participants were males and 36-50 years (56; 54.4%). The pharmacies supplied mostly Yoyo cleanser bitters® (101; 98.5%), ginseng (97; 98.5%), Jobelyn® (91; 88.3%), Ciklavit® (68; 66.6%), gingko (66; 64.1%), herbal tea (66; 64.1%), and Aloe vera (57; 55.3%). The pharmacists self-rated their knowledge of herbal medicines mostly as fair (39%) and good (42%)...