Interactions Between Herbal Medicines and Prescribed Drugs

Herb-drug interactions: an overview of systematic reviews

OBJECTIVES

The aim of this overview of systematic reviews (SRs) is to evaluate critically the evidence regarding interactions between herbal medicinal products (HMPs) and synthetic drugs.

METHODS

Four electronic databases were searched to identify relevant SRs.

RESULTS

Forty-six SRs of 46 different HMPs met our inclusion criteria. The vast majority of SRs were of poor methodological quality. The majority of these HMPs were not associated with severe herb-drug interactions. Serious herb-drug interactions were noted for Hypericum perforatum and Viscum album. The most severe interactions resulted in transplant rejection, delayed emergence from anaesthesia, cardiovascular collapse, renal and liver toxicity, cardiotoxicity, bradycardia, hypovolaemic shock, inflammatory reactions with organ fibrosis and death. Moderately severe interactions were noted for Ginkgo biloba, Panax ginseng, Piper methysticum, Serenoa repens and Camellia sinensis. The most commonly interacting drugs were antiplatelet agents and anticoagulants.

CONCLUSION

The majority of the HMPs evaluated in SRs were not associated with drug interactions with serious consequences. However, the poor quality and the scarcity of the primary data prevent firm conclusions.

Hypericum perforatum: pharmacokinetic, mechanism of action, tolerability, and clinical drug-drug interactions

Hypericum perforatum (HP) belongs to the Hypericaceae family and is one of the oldest used and most extensively investigated medicinal herbs. The medicinal form comprises the leaves and flowering tops of which the primary ingredients of interest are naphthodianthrones, xanthones, flavonoids, phloroglucinols (e.g. hyperforin), and hypericin. Although several constituents elicit pharmacological effects that are consistent with HP's antidepressant activity, no single mechanism of action underlying these effects has thus far been found. Various clinical trials have shown that HP has a comparable antidepressant efficacy as some currently used antidepressant drugs in the treatment of mild/moderate depression. Interestingly, low-hyperforin-content preparations are effective in the treatment of depression. Moreover, HP is also used to treat certain forms of anxiety. However, HP can induce various cytochrome P450s isozymes and/or P-glycoprotein, of which many drugs are substrates and which are the main origin of HP-drug interactions. Here, we analyse the existing evidence describing the clinical consequence of HP-drug interactions. Although some of the reported interactions are based on findings from in vitro studies, the clinical importance of which remain to be demonstrated, others are based on case reports where causality can, in some cases, be determined to reveal clinically significant interactions that suggest caution, consideration, and disclosure of potential interactions prior to informed use of HP.

Complementary or alternative medicine in cancer care-myths and realities

Complementary therapies are adjuncts to mainstream care, used primarily for symptom control and to enhance physical and emotional strength during and after mainstream cancer treatment. These therapies are rational, noninvasive and evidence-based that have been subjected to study to determine their value, document the problems they aim to ameliorate and define the circumstances under which they are beneficial. By contrast, 'alternative' therapies are generally promoted as such-for use as actual antitumour treatments. Typically they lack biological plausibility and scientific evidence of safety and efficacy, and many are outright fraudulent. Combining the helpful complementary therapies with mainstream oncology care to address patients' physical, psychological and spiritual needs constitutes the practice of integrative oncology. By providing patients' nonpharmacological treatment modalities that reduce symptom burden and improve quality of life, physicians enable patients to have an active role in their care, which in turn improves the physician-patient relationship, the quality of cancer care and the well-being of patients and their families.

Pharmacogenetics of clinical response to risperidone

Despite risperidone's proven safety and efficacy, existing pharmacogenetic knowledge could be applied to improve its clinical use. The present work aims to summarize the information about genetic polymorphisms affecting risperidone adverse reactions and efficacy during routine clinical practice. The most relevant genes involved in the metabolism of the drug (i.e., CYP2D6, CYP3A and ABCB1) appear to have the greatest potential to predict differences in plasma concentrations of the drug and its interactions, but also relate to side effects, such as neuroleptic syndrome, weight gain or polydipsia. Other genes that have been found in association at least twice with any adverse reactions including metabolic changes, extrapyramidal symptoms or prolactine increase are: 5HT2A; 5HT2C; 5HT6; DRD2; DRD3; and BDNF. Some of these genes (5HTR2A, DRD2 and DRD3), along with 5-HTTLPR and COMT, have also been reported to be related with negative clinical outcomes. However, there is not yet enough evidence to support their routine screening during clinical practice.

The classification and application of toxic Chinese materia medica

Many important drugs in the Chinese materia medica (CMM) are known to be toxic, and it has long been recognized in classical Chinese medical theory that toxicity can arise directly from the components of a single CMM or may be induced by an interaction between combined CMM. Traditional Chinese Medicine presents a unique set of pharmaceutical theories that include particular methods for processing, combining and decocting, and these techniques contribute to reducing toxicity as well as enhancing efficacy. The current classification of toxic CMM drugs, traditional methods for processing toxic CMM and the prohibited use of certain combinations, is based on traditional experience and ancient texts and monographs, but accumulating evidence increasingly supports their use to eliminate or reduce toxicity. Modern methods are now being used to evaluate the safety of CMM; however, a new system for describing the toxicity of Chinese herbal medicines may need to be established to take into account those herbs whose toxicity is delayed or otherwise hidden, and which have not been incorporated into the traditional classification. This review explains the existing classification and justifies it where appropriate, using experimental results often originally published in Chinese and previously not available outside China.

Piperine activates human pregnane X receptor to induce the expression of cytochrome P450 3A4 and multidrug resistance protein 1

Activation of the pregnane X receptor (PXR) and subsequently its target genes, including those encoding drug transporters and metabolizing enzymes, while playing substantial roles in xenobiotic detoxification, might cause undesired drug-drug interactions. Recently, an increased awareness has been given to dietary components for potential induction of diet-drug interactions through activation of PXR. Here, we studied, whether piperine (PIP), a major component extracted from the widely-used daily spice black pepper, could induce PXR-mediated expression of cytochrome P450 3A4 (CYP3A4) and multidrug resistance protein 1 (MDR1). Our results showed that PIP activated human PXR (hPXR)-mediated CYP3A4 and MDR1 expression in human hepatocytes, intestine cells, and a mouse model; PIP activated hPXR by recruiting its coactivator SRC-1 in both cellular and cell-free systems; PIP bound to the hPXR ligand binding domain in a competitive ligand binding assay in vitro. The dichotomous effects of PIP on induction of CYP3A4 and MDR1 expression observed here and inhibition of their activity reported elsewhere challenges the potential use of PIP as a bioavailability enhancer and suggests that caution should be taken in PIP consumption during drug treatment in patients, particularly those who favor daily pepper spice or rely on certain pepper remedies.

A review of potential harmful interactions between anticoagulant/antiplatelet agents and Chinese herbal medicines

Background

The risks attributed to drug-herb interactions, even when known, are often ignored or underestimated, especially for those involving anti-clotting drugs and Chinese medicines. The aim of this study was to structurally search and evaluate the existing evidence-based data associated with potential drug interactions between anticoagulant/antiplatelet drugs and Chinese herbal medicines (CHMs) and evaluate the documented mechanisms, consequences, and/or severity of interactions.

Methodology and Findings

Information related to anticoagulant/antiplatelet drug-CHM interactions was retrieved from eight interaction-based textbooks, four web resources and available primary biomedical literature. The primary literature searches were conducted in English and/or Chinese from January 2000 through December 2011 using the secondary databases (e.g., PubMed, Airiti Library, China Journal full-text database). The search terms included the corresponding medical subject headings and key words. Herbs or natural products not used as a single entity CHM or in Chinese Medicinal Prescriptions were excluded from further review. The corresponding mechanisms and severity ratings of interactions were retrieved using MicroMedex®, Lexicomp® and Natural Medicines Comprehensive Database®. Finally, we found 90 single entity CHMs contributed to 306 documented drug-CHM interactions. A total of 194 (63.4%) interactions were verified for its evidence describing possible mechanisms and severity. Of them, 155 interactions (79.9%) were attributable to pharmacodynamic interactions, and almost all were rated as moderate to severe interactions. The major consequences of these interactions were increased bleeding risks due to the additive anticoagulant or antiplatelet effects of the CHMs, specifically danshen, dong quai, ginger, ginkgo, licorice, and turmeric.

Conclusions/Significance

Conventional anticoagulants and antiplatelet drugs were documented to have harmful interactions with some commonly used single entity CHMs. For those patients who are taking conventional anti-clotting medications with CHMs for cardiovascular or cerebrovascular diseases, the potential risks of increased bleeding due to drug-CHM interactions should not be ignored.

The Use of Complementary and Alternative Medicine in Chronic Pain Patients in Singapore: A Single-Centre Study

Introduction: The use of complementary and alternative medicine (CAM) in Singapore for a variety of conditions has been reported to be high. However in Asian chronic pain patients, there is no data on their use of CAM and its perceived benefits. Materials and Methods: A cross-sectional survey of 210 patients was carried out in Pain Management Centre. Patients were interviewed directly on their use of CAM. The outcomes were prevalence of CAM use, the types of CAM used, the perceived efficacy and factors influencing its use. Results: The prevalence of CAM users in chronic pain is 84%. The most common class of CAM is traditional Chinese medicine (68%) the subset of which, acupuncture, was most frequently utilised (49% of patients using CAM). In univariate analyses, ethnicity was significantly linked to CAM use but not gender, age, education level and income (P = 0.027). Specifically for neck pain, it was significant that patients were more likely to see a chiropractor, to use massage, to take take vitamins and ginseng to alleviate their symptoms. With upper limb pain, it was the use of Tui na, massage and seeing a TCM practitioner. For abdominal pain, it was the use of herbal medicines. The majority felt that CAM helped with their pain (72%) although less expressed satisfaction with CAM (64%). Reasons for using CAM included: having more control over their pain; fewer side effects; safety and lower costs compared to conventional medicine. Conclusion: The use of CAM in chronic pain patients is higher than the general population. Most felt that it improved their pain. As part of multimodal therapy, CAM may have a role in the management of chronic pain. Key words: Acupuncture, CAM, Chiropracter, Efficacy

Phytomedicines for prevention and treatment of mental health disorders

Herbal medicines supported by evidence of safety and efficacy in the treatment of anxiety, insomnia, fatigue, cognitive enhancement, mental focus, and sexual function are useful as monotherapies, multiherb combinations, and as adjuncts to prescription psychotropics. Relevant mechanisms of action and clinical guidelines for herbs in common use can assist clinicians who want to enhance treatment outcomes by integrating phytomedicinals into their treatment regimens. Research is needed to strengthen the evidence base and to expand the range of disorders that can be treated with herbal extracts. Studies of herbal genomic effects may lead to more targeted and effective treatments.

Ginkgo biloba: indications, mechanisms, and safety

Ginkgo biloba special extract (EGb761) is used in most randomized control trials. Indications include cognition and memory in Alzheimer disease, age-associated dementia, cerebral insufficiency, intermittent claudication, schizophrenia, and multi-infarct dementia. Dosages range from 80 to 720 mg/d for durations of 2 weeks to 2 years. Mechanisms of action include increasing cerebral blood flow, antioxidant and antiinflammatory effects, with antiplatelet effects attributed to flavone and terpene lactones. Possible interactions with monoamine oxidase inhibitors, alprazolam, haloperidol, warfarin, and nifedipine have been reported. Optimal dosage/duration, dose-response characteristics, drug interactions, bioavailability, long-term effects, and optimal intervention timing should be the focus of future work.

Ginkgo biloba Extract for Patients with Early Diabetic Nephropathy: A Systematic Review

Objectives. To evaluate the effectiveness and safety of a Ginkgo biloba extract for patients with early diabetic nephropathy. Methods. Randomised controlled trials (RCTs) conducted on adults with early diabetic nephropathy which used Gingko biloba extract were included. The major databases were searched, and manufacturers of Gingko biloba products were contacted for information on any published or unpublished studies. Two authors independently extracted the data from the included studies. Data analysis was conducted using Review Manager 5.0 software. Results. Sixteen RCTs were included. Ginkgo biloba extract decreased the urinary albumin excretion rate (UAER), fasting blood glucose (FBG), serum creatinine (SCR), and blood urea nitrogen (BUN). The extract also improved hemorheology. The methodological quality in the included studies was low. The explicit generation of the allocation sequence was described in only 6 trials. None of the included trials were confirmed to use blinding. Three studies had observed adverse events. One study using angiotensin-converting enzyme inhibitor (ACEi) reported mild cough in both groups. No serious adverse effects were reported. Conclusions. Gingko biloba extract is a valuable drug which has prospect in treating early diabetic nephropathy, especially with high UAER baseline level. The safety for early diabetic nephropathy is uncertain. Long-term, double-blinded RCTs with large sample sizes are still needed to provide stronger evidence.

Complementary and alternative medicine use by pediatric specialty outpatients

OBJECTIVE

Complementary and alternative medicine (CAM) use is high among children and youth with chronic illnesses. The objective of this study was to assess the prevalence and patterns of CAM use in 10 subspecialty clinics in Canada and to compare CAM use between 2 geographically diverse locations.

METHODS

This survey was carried out at 1 Children's Hospital in western Canada (Edmonton) and 1 Children's Hospital in central Canada (Ottawa). Questionnaires were completed by parents in either French or English.

RESULTS

Although demographic characteristics of the 2 populations were similar, CAM use at the western hospital was 71% (n = 704) compared with 42% (n = 222) at the central hospital (P < .0001). Most respondents agreed or strongly agreed that they feel comfortable discussing CAM in their clinic. The most common CAM products currently used were multivitamins/minerals, herbal products, and homeopathic remedies. The most common CAM practices currently used were massage, chiropractic, relaxation, and aromatherapy. Eighty adverse effects were reported, and 55 (68.8%) of these were self-assessed as minor.

CONCLUSIONS

Results of this study indicate that CAM use is high among pediatric specialty clinic outpatients and is much greater in the western than in the central hospital. Most respondents felt that their CAM use was helpful with few or no harms associated. Many patients, using CAM alongside their conventional medicines, are still not discussing their CAM use with their physicians and are increasing the likelihood for potential interactions and preventable harms.

Vietnamese traditional medicine from a pharmacist's perspective

Traditional medicine plays an important role in the healthcare system of Vietnam. Vietnamese traditional medicine (VTM) is underpinned by the oriental philosophy and theory of healing. VTM is largely influenced by traditional Chinese medicine, but differs to a certain extent. VTM is largely not evidence-based from a clinical perspective but subclinical research data from the past decades support the traditional use of many herbal VTM drugs. For safe use, knowledge of the occurrence of adverse reactions and herb-drug interactions is necessary. The Vietnamese government supports further development of VTM in a scientific way and integration of VTM with Western medicine. This article first gives an overview of the general aspects of VTM (historical perspective, regulatory aspects, comparison with traditional Chinese medicine, philosophical background, the Vietnamese market situation, quality assurance and formulations), and subsequently focuses on its safe and effective use in Vietnamese clinical pharmacy and medical practice.

Ethical implications of the increasing use of complementary and alternative medicine

BACKGROUND

The increasing demand for complementary and alternative medicine (CAM) raises ethical questions about specific aspects of both CAM and conventional medicine (COM).

METHODS

The present article provides a critical survey of the most important ethical aspects in the current debate about CAM.

RESULTS

The relevant ethical issues arise mainly in 4 main areas: 1) patient information, 2) research ethics, 3) cost, and 4) education. Most of the contributions used for our purpose are based upon the implicit assumption that, in principle, the ethics of CAM and COM have to be identical because of the same underlying doctor-patient relationship. This premise is shared by the author.

CONCLUSIONS

Substantial efforts on various levels will have to be made in order to create the conditions necessary for CAM to be ethically justified. But the ethical implications for COM also have to be considered.

A Blended Learning Course Design in Clinical Pharmacology for Post-graduate Dental Students

Postgraduate courses in clinical pharmacology are important for dentists to be updated on drug therapy and information related to their clinical practice, as well as knowledge of relevant adverse effects and interactions. A traditional approach with classroom delivery as the only method to teaching and learning has shortcomings regarding flexibility, individual learning preferences, and problem based learning (PBL) activities compared to online environments. This study examines a five week postgraduate course in clinical pharmacology with 15 hours of lectures and online learning activities, i.e. blended course design. Six postgraduate dental students participated and at the end of the course they were interviewed. Our findings emphasize that a blended learning course design can be successfully used in postgraduate dental education. Key matters for discussion were time flexibility and location convenience, change in teacher's role, rein-forced learning strategies towards professional needs, scarcity in online communication, and proposed future utilization of e-learning components.

Clinical pharmacology in sleep medicine

The basic treatment goals of pharmacological therapies in sleep medicine are to improve waking function by either improving sleep or by increasing energy during wakefulness. Stimulants to improve waking function include amphetamine derivatives, modafinil, and caffeine. Sleep aids encompass several classes, from benzodiazepine hypnotics to over-the-counter antihistamines. Other medications used in sleep medicine include those initially used in other disorders, such as epilepsy, Parkinson's disease, and psychiatric disorders. As these medications are prescribed or encountered by providers in diverse fields of medicine, it is important to recognize the distribution of adverse effects, drug interaction profiles, metabolism, and cytochrome substrate activity. In this paper, we review the pharmacological armamentarium in the field of sleep medicine to provide a framework for risk-benefit considerations in clinical practice.

What do most erectile dysfunction guidelines have in common? No evidence-based discussion or recommendation of heart-healthy lifestyle changes and/or Panax ginseng

Sexual health or erectile dysfunction (ED) state of the art guidelines provide a thorough overview of conventional prescription or other notable extrinsic treatment options. Yet, over the past 10-15 years, a plethora of international researchers have established that individual and comprehensive lifestyle changes can prevent and potentially improve ED. We review the lifestyle evidence that should equate to grade A or level 1 evidence recommendations for ED. We also review the evidence for Panax ginseng, an over-the-counter (OTC) dietary supplement with a 35-year history of laboratory investigations, multiple positive randomized trials over approximately 15 years and several independent meta-analyses and systematic reviews. Perhaps it is time to at least discuss and even emphasize lifestyle and other non-conventional interventions in ED guidelines so that patients can explore a diversity of potentially synergistic choices with their physicians and can improve their quality and quantity of life. Ignoring the consistent, positive data on lifestyle modifications in ED guidelines, for example, is tantamount to ignoring diet and lifestyle changes to reduce the risk of or ameliorate cardiovascular diseases.

Psychotropic drug-drug interactions involving P-glycoprotein

Multidrug resistance P-glycoprotein (P-gp; also known as MDR1 and ABCB1) is expressed in the luminal membrane of the small intestine and blood-brain barrier, and the apical membranes of excretory cells such as hepatocytes and kidney proximal tubule epithelia. P-gp regulates the absorption and elimination of a wide range of compounds, such as digoxin, paclitaxel, HIV protease inhibitors and psychotropic drugs. Its substrate specificity is as broad as that of cytochrome P450 (CYP) 3A4, which encompasses up to 50 % of the currently marketed drugs. There has been considerable interest in variations in the ABCB1 gene as predictors of the pharmacokinetics and/or treatment outcomes of several drug classes, including antidepressants and antipsychotics. Moreover, P-gp-mediated transport activity is saturable, and is subject to modulation by inhibition and induction, which can affect the pharmacokinetics, efficacy or safety of P-gp substrates. In addition, many of the P-gp substrates overlap with CYP3A4 substrates, and several psychotropic drugs that are P-gp substrates are also CYP3A4 substrates. Therefore, psychotropic drugs that are P-gp substrates may cause a drug interaction when P-gp inhibitors and inducers are coadministered, or when psychotropic drugs or other medicines that are P-gp substrates are added to a prescription. Hence, it is clinically important to accumulate data about drug interactions through studies on P-gp, in addition to CYP3A4, to assist in the selection of appropriate psychotropic medications and in avoiding inappropriate combinations of therapeutic agents. There is currently insufficient information available on the psychotropic drug interactions related to P-gp, and therefore we summarize the recent clinical data in this review.

Evaluation of documented drug interactions and contraindications associated with herbs and dietary supplements: a systematic literature review

BACKGROUND AND AIMS

The use of herbs and dietary supplements (HDS) alone or concomitantly with medications can potentially increase the risk of adverse events experienced by the patients. This review aims to evaluate the documented HDS-drug interactions and contraindications.

METHODS

A structured literature review was conducted on PubMed, EMBASE, Cochrane Library, tertiary literature and Internet.

RESULTS

While 85 primary literatures, six books and two web sites were reviewed for a total of 1,491 unique pairs of HDS-drug interactions, 213 HDS entities and 509 medications were involved. HDS products containing St. John's Wort, magnesium, calcium, iron, ginkgo had the greatest number of documented interactions with medications. Warfarin, insulin, aspirin, digoxin, and ticlopidine had the greatest number of reported interactions with HDS. Medications affecting the central nervous system or cardiovascular system had more documented interactions with HDS. Of the 882 HDS-drug interactions being described its mechanism and severity, 42.3% were due to altered pharmacokinetics and 240 were described as major interactions. Of the 152 identified HDS contraindications, the most frequent involved gastrointestinal (16.4%), neurological (14.5%), and renal/genitourinary diseases (12.5%). Flaxseed, echinacea, and yohimbe had the largest number of documented contraindications.

CONCLUSIONS

Although HDS-drug interactions and contraindications primarily concerned a relatively small subset of commonly used medications and HDS entities, this review provides the summary to identify patients, HDS products, and medications that are more susceptible to HDS-drug interactions and contraindications. The findings would facilitate the health-care professionals to communicate these documented interactions and contraindications to their patients and/or caregivers thereby preventing serious adverse events and improving desired therapeutic outcomes.

Modes of embodiment in breast cancer patients using complementary and alternative medicine

Breast cancer patients are frequent users of complementary and alternative medicine (CAM). They often have complex reasons for, and experiences from, their use of CAM. Bodily experiences are important and almost unexplored elements in CAM use. Our aim was to explore the meaning and importance of bodily experiences among breast cancer patients who were using CAM as a supplement or an alternative to conventional treatment (CT). Our findings based on qualitative interviews with 13 women suggest that bodily experiences were particularly important when positioned outside conventional health care prior to medical diagnosis and as users of CAM as alternative to CT. We introduce three central modes of embodiment related to CAM use: the right to one's body, the body used as a gauge, and the body used as a guide. Patients' positioning between treatment systems should be further explored from a bodily perspective to safeguard and optimize their treatment choices.

The exposure of highly toxic aconitine does not significantly impact the activity and expression of cytochrome P450 3A in rats determined by a novel ultra performance liquid chromatography-tandem mass spectrometric method of a specific probe buspirone

Aconitum species are widely used to treat rheumatism, cardiovascular diseases, and tumors in China and other Asian countries. The herbs are always used with drugs such as paclitaxel. Aconitine (AC) is one of the main bioactive/high-toxic alkaloids of Aconitum roots. AC is metabolized by cytochrome P450 (CYP) 3A. However, whether AC inhibits/induces CYP3A, which causes drug-drug interaction (DDI) is unclear. Our study aims to explore the potent effects of AC, as a marker component of Aconitum, on CYP3A using the probe buspirone in rats. The effects of oral AC on pharmacokinetics of buspirone were evaluated. CYP3A activity and protein levels in rat liver microsomes pretreated with oral AC were also measured using in vitro buspirone metabolism and Western blot. Buspirone and its major metabolites 1-(2-pyrimidinyl)piperazine and 6'-hydroxybuspirone were determined using a newly validated UPLC-MS/MS method. Single dose and 7-day AC administration at 0.125mg/kg had no effect on CYP3A activity since no change in the formation of 1-(2-pyrimidinyl)piperazine and 6'-hydroxybuspirone. CYP3A activity and protein levels in liver microsomes were also not affected by 7-day AC pretreatment at 0.125mg/kg. Therefore, AC neither inhibits nor induces CYP3A in rats, indicating AC does not cause CYP3A-related DDI in the liver.

A prospective study on the safety of herbal medicines, used alone or with conventional medicines

ETHNOPHARMACOLOGICAL RELEVANCE

Along with increase of herbal medicine use worldwide, the safety of traditional herbal medicines frequently becomes a medical issue.

AIM OF THE STUDY

This study aimed to investigate the incidence of herbal medicine-induced adverse effects on liver functions.

SUBJECTS AND METHODS

A prospective study was performed with 313 inpatients (87 male and 226 female) receiving herbal prescriptions during hospitalization. The patients were classified into two groups based on their treatments: one group received herbal medicines only (57 patients), and another received herbal and conventional medicines concurrently (256 patients). All patients were given liver and renal function tests at the start of hospitalization (baseline) and at approximately 2-week intervals thereafter, until discharge.

RESULTS

Six of the 313 patients showed abnormal liver function without related clinical symptoms (1.9%, 95% CI 0.38-3.41); none of the patients in the herbal group had abnormal result in liver function tests (0% of 57 patients) while all six had received a combination of herbal and conventional medicines (2.3% of 256 patients, 95% CI 0.46-4.14).

CONCLUSION

Our findings indicate that herbal drugs used alone are relatively safe, but the risk for adverse reactions may increase when herbal and conventional drugs are taken concurrently.

Alternative therapies for asthma: are patients at risk?

Asthma patients often try some form of alternative medicine. This article questions whether this is good or bad. Systematic reviews fail to demonstrate that the treatments in question are demonstrably effective. Other data raise considerable concern over the safety of some forms of alternative medicine. Thus the risk-benefit balance fails to be positive. Patients are often mislead to believe otherwise and physicians should inform their asthma patients responsibly about the value of alternative medicine.

What is integrative oncology and can it help my patients?

Integrative oncology lends itself to the comprehensive practice of gynecologic oncology with multiple tools and interventions that can impact on QoL and survival. However, there remains a paucity of well-designed, well-powered randomized control trials on various CAM modalities for gynecologic cancer patients. The reasons for the lack of level 1 evidence include the nascent state of integrative medicine as a science, the limitations on CAM funding, the relative lack of integration of CAM practitioners into the oncology community, and absence of strict regulation of herbs and supplements by the US FDA. The use of CAM as adjunctive therapies will likely continue given the patient-driven trends to date, and given the evidence for at least safety and potentially efficacy, our patients deserve our willingness to use all possible approaches to improving their outcomes. Continued evolution of our ability to specifically measure and describe QoL will further our ability to hone in on domains most important to patients and their survival and allow practitioners to make patient-specific recommendations. Multimodal programs that include physical activity, stress management, and diet have the potential to address demonstrated deficits in PWB and FWB in ovarian cancer patients which suggests a model of collaborative gynecologic oncology care). Integrative oncology represents a holistic approach to patient care whose goal is maximization of patient quantity and quality of life. Patients can achieve this optimal outcome through the synergy of conventional care, integrative modalities, lifestyle modifications, and supportive care. Refer to Table 4 for a listing of integrated medicine Internet resources.

Inhibitory effects of cytochrome P450 enzymes CYP2C8, CYP2C9, CYP2C19 and CYP3A4 by Labisia pumila extracts

ETHNOPHARMACOLOGICAL RELEVANCE

Labisa pumila (LP), popularly known with its local name, Kacip Fatimah, is a well known herb grown in Indochina and Southeast Asia and is traditionally used to regain energy after giving birth in women. The propensity of LP to cause drug-herb interaction via cytochrome P450 (CYP) enzyme system has not been investigated.

AIM OF THE STUDY

To evaluate the in vitro inhibitory effects of various LP extracts (aqueous, ethanol, dichloromethane (DCM) and hexane) on cytochrome P450 2C8 (CYP2C8), CYP2C9, CYP2C19 and CYP3A4 activities.

MATERIALS AND METHODS

Probe substrate-based high performance liquid chromatography (HPLC) methods were established for CYP2C9, CYP2C19 and CYP3A4 whereas a fluorescence-based enzyme assay was established for CYP2C8. The metabolite formations were examined after incubation of probe substrate with respective CYP isoform in the present or absent of LP extracts. The inhibitory effect of LP was characterized with kinetic parameters IC(50) and K(i) values.

RESULTS

LP extracts showed differential effect of CYP activities with the order of inhibitory potency as follows: dichloromethane>hexane>ethanol>aqueous. This differential effect was only observed in CYP2C isoforms but not CYP3A4. Both the hexane and DCM extracts exhibited moderate to potent inhibition towards CYP2C activities in different modes including non-competitive, competive and mixed-type. The DCM effect was notably strong for CYP2C8 and CYP2C9 showing K(i) values of below 1 μg/ml. The selectivity of LP for CYP2C isoforms rather than CYP3A4 may be attributed to the presence of relatively small, lipophilic yet slightly polar compounds within the LP extracts.

CONCLUSIONS

The results of our study revealed that phytoconstituents contained in LP, particularly in hexane and dichloromethane extracts, were able to selectively inhibit CYP2C isoforms. The inactivation was characterized by low K(i) values, in particular, in CYP2C8 and CYP2C9. These in vitro data indicate that LB preparations contain constituents that can potently inhibit CYP2C activities and suggest that this herb should be examined for potential pharmacokinetic drug interactions in vivo.

Potential of treating age-related depression and cognitive decline with nutraceutical approaches: a mini-review

A variety of consumable plant-derived phytochemicals exhibit nutraceutical properties because they produce physiological benefits and combat disease processes. Emerging evidence suggests that widely accessible and safe organic polyphenolic phytochemicals, in particular, treat depression at much lower concentrations than clinical doses of classical drugs. Structurally similar polyphenolics such as curcumin, resveratrol, and proanthocyanidins exhibit antioxidant and immunomodulatory properties and recent research suggests that they also modulate hypothalamic-pituitary-adrenal (HPA) axis activity, serotonergic transmission and hippocampal neurogenesis (perhaps via their effects on serotonin and HPA activity). These data tempt speculation that polyphenolic compounds could also combat age-related cognitive decline, which is often accompanied by depression and potentially by reduced levels of hippocampal neurogenesis. Here we review the relationships between dysregulation of these systems and age-related cognitive decline. We then suggest that this group of structurally similar polyphenolic compounds may be particularly promising therapeutic leads for age-related cognitive decline and depression because they modulate these processes.

Policy implications of complementary and alternative medicine use in Australia: data from the National Health Survey

OBJECTIVES

The objective of this study was to investigate the drivers of complementary and alternative medicine (CAM) use in the general population in Australia and to identify key policy implications.

DATA AND METHODS

The National Health Survey 2007/2008, a representative survey of the Australian population, provides information on CAM use (practitioners and products) in the last 12 months. All adult respondents (N=15,779) aged 18 years or older are included in this study. Logistic regression is employed to determine the effect of socio-economic, condition-specific, health behavior variables, and private health insurance status on CAM use.

RESULTS

In addition to socio-economic variables known to affect CAM use, individuals who have a chronic condition, particularly a mental health condition, are more likely to use CAM. There does not appear to be a correlation between CAM use and more frequent General Practitioner use; however, ancillary private health insurance is correlated with a greater likelihood of CAM use, as expected.

CONCLUSIONS

The Australian government does not currently intervene in the CAM market in a systematic way. CAM is clearly considered to be a legitimate and important component of health care for many Australians, despite the limited availability of clinical evidence for its efficacy and safety. Policy interventions may include the regulation of CAM products, practitioners, and information as well as providing subsidies for cost-effective modalities.

Herb-drug interaction between Echinacea purpurea and etravirine in HIV-infected patients

The aim of this open-label, fixed-sequence study was to investigate the potential of the botanical supplement Echinacea purpurea to interact with etravirine, a nonnucleoside reverse transcriptase inhibitor of HIV. Fifteen HIV-infected patients receiving antiretroviral therapy with etravirine (400 mg once daily) for at least 4 weeks were included. E. purpurea root/extract-containing capsules were added to the antiretroviral treatment (500 mg every 8 h) for 14 days. Etravirine concentrations in plasma were determined by high-performance liquid chromatography immediately before and 1, 2, 4, 6, 8, 10, 12, and 24 h after a morning dose of etravirine on day 0 and etravirine plus E. purpurea on day 14. Individual etravirine pharmacokinetic parameters were calculated by noncompartmental analysis and compared between days 0 and 14 by means of the geometric mean ratio (GMR) and its 90% confidence interval (CI). The median age was 46 years (interquartile range, 41 to 50), and the median body weight was 76 kg (interquartile range, 68 to 92). Echinacea was well tolerated, and all participants completed the study. The GMR for etravirine coadministered with E. purpurea relative to etravirine alone was 1.07 (90% CI, 0.81 to 1.42) for the maximum concentration, 1.04 (90% CI, 0.79 to 1.38) for the area under the concentration-time curve from 0 to 24 h, and 1.04 (90% CI, 0.74 to 1.44) for the concentration at the end of the dosing interval. In conclusion, the coadministration of E. purpurea with etravirine was safe and well tolerated in HIV-infected patients; our data suggest that no dose adjustment for etravirine is necessary.

Use of complementary and alternative medicine for physical performance, energy, immune function, and general health among older women and men in the United States

We examined use of complementary and alternative medicine (CAM) for health and well-being by older women and men. Data were from the 2007 National Health Interview Survey, representing 89.5 million Americans ages 50+. Multivariate logistic regression accounted for the survey design. For general health, 52 million people used CAM. The numbers for immune function, physical performance, and energy were 21.6, 15.9, and 10.1 million respectively. In adjusted results, women were much more likely than men to use CAM for all four reasons, especially energy. Older adults, particularly women, could benefit from research on CAM benefits and risks.

Rainforest pharmacopeia in Madagascar provides high value for current local and prospective global uses

Botanical diversity provides value to humans through carbon sequestration, air and water purification, and the provisioning of wild foods and ethnomedicines. Here we calculate the value of botanical ethnomedicines in a rainforest region of Madagascar, the Makira Protected Area, using a substitution method that combines replacement costs and choice modeling. The Makira watershed may comprise approximately 0.8% of global botanical diversity and possesses enormous value both in its ability to provision botanical ethnomedicines to local people and as a source of potentially novel pharmaceutical drugs for society as a whole. Approximately 241 locally-recognized species are used as ethnomedicines, including 113 agricultural or weed species. We equated each ethnomedicinal treatment to the monetary value of a comparable pharmaceutical treatment adjusted by personal preferences in perceived efficacy (rather than from known or assumed medicinal equivalency). The benefit value of these botanical ethnomedicines per individual is $5.40–7.90 per year when using the value of highly subsidized Malagasy pharmaceuticals and $100.60–287.40 when using the value of American pharmaceuticals. Using local pharmaceuticals as substitutes, the value per household is $30.24–44.30 per year, equivalent to 43–63% of median annual household income, demonstrating their local importance. Using the value of American pharmaceuticals, the amount is equivalent to 22–63% of the median annual health care expenditures for American adults under 45 in 2006. The potential for developing novel biomedicines from the Makira watershed’s unique flora ranges in untapped benefit value from $0.3–5.7 billion for American pharmaceutical companies, non-inclusive of the importance of providing novel medicines and improved healthcare to society. This study provides evidence of the tremendous current local and prospective global value of botanical ethnomedicines and furthers arguments for the conservation of tropical forests for sustainable use.

Botanique de la diversité apporte de la valeur à l’homme par la séquestration du carbone, de l’air et de purification de l’eau, et le provisionnement des aliments sauvages et ethnomedicines. Ici, nous calculons la valeur de ethnomedicines botaniques dans une région de forêt de Madagascar, la zone protégée de Makira, en utilisant une méthode de substitution qui combine les coûts de remplacement et la modélisation des choix. Le bassin versant de Makira peut comprendre environ 0,8% de la diversité botanique mondiale et possède une valeur énorme à la fois dans sa capacité à fournir ethnomedicines botaniques à la population locale et en tant que source de nouveaux médicaments potentiellement pharmaceutiques pour la société dans son ensemble. Environ 241 espèces localement reconnus sont utilisés comme ethnomedicines, y compris 113 espèces d’agricoles ou de mauvaises herbes. Nous assimilé chaque traitement ethnomédicales à la valeur monétaire d’un traitement comparable pharmaceutique ajusté en fonction des préférences personnelles en matière d’efficacité perçue (plutôt que de l’équivalence médicament connu ou supposé). La valeur de l’avantage de ces ethnomedicines botaniques par individu est de $5,40 à 7.90 par année lors de l’utilisation de la valeur des produits pharmaceutiques malgaches fortement subventionnés et de $100,60 à 287,40 lors de l’utilisation de la valeur des produits pharmaceutiques américains. Utilisation de produits pharmaceutiques locales comme des substituts, la valeur par ménage est de $30.24 à 44.30 par an, équivalent à 43–63% du revenu médian des ménages annuelle, ce qui démontre leur importance locale. Utilisation de la valeur des produits pharmaceutiques américaines, le montant est équivalent à 22–63% de la médiane des dépenses annuelles de soins de santé pour les adultes américains de moins de 45 en 2006. Le potentiel de développement de nouveaux biomédicaments des fourneaux dans le bassin versant de la flore Makira unqiue de la valeur des avantages inexploité de $0,3 à 5,7 milliards pour les sociétés pharmaceutiques américaines, non compris l’importance de fournir de nouveaux médicaments et de soins de santé amélioré à la société. Cette étude fournit une preuve de l’énorme valeur actuelle globale locale et prospective de ethnomedicines botaniques et des arguments fait avancer pour la conservation des forêts tropicales pour l’utilisation durable.

Hepatic cytochrome P450 mediates interaction between warfarin and Coleus forskohlii extract in vivo and in vitro

Objectives

This study aimed to determine whether Coleus forskohlii extract (CFE) influences the anticoagulant action of warfarin in mice in vivo and its relationship with hepatic cytochrome P450 (CYP).

Methods

Mice were fed various doses of CFE standardised with 10% forskolin in a normal diet for one week, or in protein diets containing 7% and 20% casein (low and normal) for four weeks. They were then administered with warfarin by gavage on the last two days of the treatment regimen, and blood coagulation parameters, as well as hepatic CYP, were analysed at 18 h after the last dose. Direct interaction between CFE and forskolin with CYP2C was evaluated in vitro.

Key findings

CFE dose dependently increased hepatic total CYP content and S-warfarin 7-hydroxylase activity at a dietary level of ≥0.05%. Warfarin-induced anticoagulation was attenuated by CFE in parallel with CYP induction. The findings were similar in mice fed diets containing CFE and different ratios of protein. CFE directly inhibited CYP2C activity in mouse and human liver microsomes in vitro, whereas forskolin was only slightly inhibitory.

Conclusions

CFE attenuates the anticoagulant action of warfarin by inducing hepatic CYP2C; thus, caution is required with the combination of warfarin and dietary supplements containing CFE.

In vitro and in situ evaluation of herb-drug interactions during intestinal metabolism and absorption of baicalein

ETHNOPHARMACOLOGICAL RELEVANCE

Baicalein (B), a bioactive flavone isolated from the root of a traditional Chinese medicinal herb Scutellaria baicalensis Georgi, was found to undergo extensive intestinal Phase II metabolism during its absorption process. Compounds sharing the same metabolic pathways with B or being inhibitors of enzymes UGT and SULT are expected to interfere with the metabolism of B leading to alteration of the absorption of B. The present study aims to identify potential intestinal absorption and metabolism interactions between B and four selected compounds, namely acetaminophen (APAP), (-)-epicatechin (EC), piperine (PIP) and curcumin (CUR) using in vitro and in situ models.

MATERIALS AND METHODS

Three in vitro and one in situ methods were employed to investigate the effect of selected compounds on the metabolism and absorption on B. Incubation studies using rat intestinal s9 and Caco-2 cell lysate were used to study the effect of selected compounds on glucuronidation and sulfation of B. Sigmoidal dose-response curves were plotted and IC(50) values were estimated. Apical to basolateral absorption study using Caco-2 cell monolayer model was also employed to study the effect of selected compounds on absorption of B. The most potent inhibitor identified was selected to further investigate its potential herb-drug interaction with B using in situ rat intestinal perfusion model. LC/MS/MS was used for the analysis of B and its metabolites in collected samples.

RESULTS

It was found that all the four selected compounds could produce a dose-dependent inhibition on the glucuronidation and sulfation of B. Moreover, the presence of CUR and high-dose EC demonstrated a subsequent increase in the absorption of B. In general, the order of potency on glucuronidation inhibition is: CUR>PIP>EC>APAP; while the potency order on sulfation inhibition is: CUR>EC>PIP>APAP. CUR was selected to further study its in vivo effect on B using in situ rat intestinal perfusion model. It was found that CUR could significantly increase the absorption of B via the inhibition on formation of its metabolites.

CONCLUSIONS

Our findings indicated that the intestinal metabolism of B could be inhibited by all the selected compounds with CUR being the most potent inhibitor, which could result in subsequent increase of absorption of B. The current study had significant implications for further investigation on the in vivo evaluations of the herb-drug and herb-herb interactions between B and selected compounds, especially CUR.

Effect of milk thistle on the pharmacokinetics of darunavir-ritonavir in HIV-infected patients

The aim of this open-label, fixed-sequence study was to investigate the potential of the botanical supplement milk thistle (silymarin) to interact with the boosted protease inhibitor combination darunavir-ritonavir. Fifteen HIV-infected patients receiving antiretroviral therapy with darunavir-ritonavir (600/100 mg twice daily) for at least 4 weeks were included. Silymarin (150 mg every 8 h) was added to the antiretroviral treatment from days 1 to 14. Darunavir concentrations in plasma were determined by high-performance liquid chromatography immediately before and 1, 2, 4, 6, 8, 10, and 12 h after a morning dose of darunavir-ritonavir on day 0 and darunavir-ritonavir plus silymarin on day 14. Individual darunavir pharmacokinetic parameters were calculated by noncompartmental analysis and compared between days 0 and 14 by means of the geometric mean ratio (GMR) and its 90% confidence interval (CI). The median age was 48 years (interquartile range, 44 to 50 years), and the median body weight was 70 kg (interquartile range, 65 to 84 kg). Silymarin was well tolerated, and all participants completed the study. The GMRs for darunavir coadministered with silymarin relative to darunavir alone were 0.86 (90% CI, 0.70 to 1.05) for the area under the concentration-time curve from 0 to 12 h, 0.83 (90% CI, 0.80 to 0.98) for the maximum concentration, and 0.94 (90% CI, 0.73 to 1.19) for the concentration at the end of the dosing interval. In summary, coadministration of silymarin with darunavir-ritonavir seems to be safe in HIV-infected patients; no dose adjustment for darunavir-ritonavir seems to be necessary.

Herbal medicine, Chaplin, and "The Kid"

At variance with other largely safe complementary alternative medicines like homeopathy and acupuncture, which only carry the risk of inducing patients to shun effective treatment, herbal remedies are real, albeit impure, drugs and therefore fully capable of producing undesirable consequences if misused. The advantages they offer are uncertain since genuine evidence of efficacy and effectiveness is present in only a few cases. A result of this imbalance is that studies in this field are considerably more meaningful when they deal with untoward effects than with therapeutic uses. This disproportion has suggested to us the curious similarity with the situation portrayed in the film "The Kid" where the essential task of the protagonist (Chaplin) is to repair the windows his stone-throwing child has just broken.

Influence of Panax ginseng on cytochrome P450 (CYP)3A and P-glycoprotein (P-gp) activity in healthy participants

A number of herbal preparations have been shown to interact with prescription medications secondary to modulation of cytochrome P450 (CYP) and/or P-glycoprotein (P-gp). The purpose of this study was to determine the influence of Panax ginseng on CYP3A and P-gp function using the probe substrates midazolam and fexofenadine, respectively. Twelve healthy participants (8 men) completed this open-label, single-sequence pharmacokinetic study. Healthy volunteers received single oral doses of midazolam 8 mg and fexofenadine 120 mg, before and after 28 days of P ginseng 500 mg twice daily. Midazolam and fexofenadine pharmacokinetic parameter values were calculated and compared before and after P ginseng administration. Geometric mean ratios (postginseng/preginseng) for midazolam area under the concentration-time curve from zero to infinity (AUC(0-∞)), half-life (t(1/2)), and maximum concentration (C(max)) were significantly reduced at 0.66 (0.55-0.78), 0.71 (0.53-0.90), and 0.74 (0.56-0.93), respectively. Conversely, fexofenadine pharmacokinetics were unaltered by P ginseng administration. Based on these results, P ginseng appeared to induce CYP3A activity in the liver and possibly the gastrointestinal tract. Patients taking P ginseng in combination with CYP3A substrates with narrow therapeutic ranges should be monitored closely for adequate therapeutic response to the substrate medication.