Drug Interactions Between Herbal and Prescription Medicines

The interaction potential of herbal medicinal products: a luminescence-based screening platform assessing effects on cytochrome P450 and its use with devil's claw (Harpagophyti radix) preparations

Objectives

Potential interactions between herbal medicinal products and the cytochrome (CYP) P450 system are an important safety concern. We set out to develop a screening panel for assessing such interactions and use it to evaluate the interaction potential of devil's claw.

Methods

The panel consisted of luminescence-based inhibition assays for CYP1A2, 2C9, 2C19, 2D6 and 3A4, and a reporter gene (luciferase) assay for pregnane X receptor (PXR) activation and CYP3A4 induction. Caftaric acid and chlorogenic acid, two compounds with strong fluorescence quenching properties, were used to demonstrate the assay's resistance to interference. We tested 10 commercial devil's claw preparations as well as harpagoside and harpagide, two important constituents of devil's claw.

Key findings

Five preparations were found to weakly inhibit CYP3A4 (IC50 124.2–327.6 µg/ml) and five were found to weakly activate PXR (EC50 10.21–169.3 µg/ml). Harpagoside and harpagide did not inhibit CYP3A4. In agreement with published data, bergamottin, a natural product known to interact with CYP3A4, was shown to inhibit CYP3A4 with an IC50 of 13.63 µm and activate PXR with an EC50 of 6.7 µm.

Conclusions

Devil's claw preparations are unlikely to have a clinically relevant effect on CYP function. The assay panel proved effective in screening devil's claw preparations, demonstrating its suitability for use with plant extracts. It showed superior sensitivity and resistance to interference.

Herb-drug pharmacokinetic interactions reviewed

IMPORTANCE OF THE FIELD

the global increase in the popularity of alternative medicines has raised renewed concerns regarding herb-drug interactions. These interactions are especially important for drugs with narrow therapeutic indices and may either be pharmacodynamic or pharmacokinetic in nature.

AREAS COVERED IN THIS REVIEW

pharmacokinetic interactions which may exist between herbs and drugs, and the mechanisms of these interactions with appropriate examples based on primary and secondary data in publications are discussed. The mechanisms covered include those that affect oral drug absorption (e.g., modulation of efflux and uptake transporters, complex formation, gastrointestinal motility and pH) and drug biotransformation (e.g., inhibition or induction of enzymes).

WHAT THE READER WILL GAIN

knowledge on the mechanisms of herb-drug pharmacokinetic interactions supported by an extended list of these types of interactions for quick reference. A critical evaluation of certain herb-drug pharmacokinetic interactions reported in the scientific literature.

TAKE HOME MESSAGE

as the incidence and severity of herb-drug pharmacokinetic interactions increase due to a worldwide rise in the use of herbal preparations, more clinical data regarding herb-drug pharmacokinetic interactions are needed to make informed decisions regarding patient safety.

Should herbs take all the blame? Causality assessment of a serious thrombocytopenia event

BACKGROUND

With the increasing use of herbal medicines, the causality assessment of adverse drug-related reactions becomes more complicated because of the concomitant use of herbs and conventional medications. Epidemiological causal inference can be a central feature of such judgment but may be insufficient. Other scientific considerations include study design, bias, confounding, and measurement issues. The approach of this study is to establish an active safety surveillance system for finished herbal products (FHPs) and to review each adverse event regularly.

METHOD

A single case of serious thrombocytopenia was found in 136 subjects taking FHPs on a clinical trial for 12 weeks, for which the cause was sought.

RESULTS

Because at the end of the first month the patient's platelet counts were normal and the thrombocytopenia developed after the co-medication with conventional drugs, it was suspected that the thrombocytopenia might not be attributed to the use of FHP.

CONCLUSIONS

This report summarizes the criteria of causality assessment under mixed use of herbs and conventional medicine and recommends a feasible process for careful evaluation of adverse drug reactions related to all herbal medicine.

Garlic flavonoids and organosulfur compounds: impact on the hepatic pharmacokinetics of saquinavir and darunavir

The therapeutic efficacy of saquinavir and darunavir is affected by the presence of xenobiotics (such as garlic compounds) capable of modifying transporter-enzyme interplay. To ascertain the mechanism of interactions between antiretroviral drugs and garlic supplements and to identify the garlic constituents responsible, the hepatic pharmacokinetics of two antiretroviral drugs was investigated in the presence of garlic phytochemicals and aged garlic extract. For this purpose, rat liver slices and isolated rat hepatocytes were used. Aged garlic extract significantly inhibited saquinavir efflux from rat hepatocytes, while the efflux of darunavir significantly increased. Phytochemicals inducing distribution changes of saquinavir and darunavir were most probably flavonoids and lipophilic organosulfur compounds, respectively. All tested phytochemicals (except S-allyl L-cysteine) and aged garlic extract inhibited CYP3A4 metabolism of both drugs and modulated hepatic distribution of the corresponding saquinavir and darunavir metabolites. The competition between saquinavir and garlic constituent(s) for the same binding site on the efflux transporter and the positive cooperative effect between darunavir and garlic phytochemical(s), which bind to separate binding places on transporter, are the most probable mechanisms explaining the plasma profile changes, which could occur in vivo during concomitant consumption of antiretrovirals and garlic supplements.

Use of complementary and alternative medicine for treatment among African-Americans: a multivariate analysis

BACKGROUND

The use of complementary and alternative medicine (CAM) is substantial among African-Americans; however, research on characteristics of African-Americans who use CAM to treat specific conditions is scarce.

OBJECTIVE

To determine what predisposing, enabling, need, and disease-state factors are related to CAM use for treatment among a nationally representative sample of African-Americans.

METHODS

A cross-sectional study design was employed using the 2002 National Health Interview Survey (NHIS). A nationwide representative sample of adult (> or =18 years) African-Americans who used CAM in the past 12 months (n=16,113,651 weighted; n=2,952 unweighted) was included. The Andersen Health Care Utilization Model served as the framework with CAM use for treatment as the main outcome measure. Independent variables included the following: predisposing (eg, age, gender, and education); enabling (eg, income, employment, and access to care); need (eg, health status, physician visits, and prescription medication use); and disease state (ie, most prevalent conditions among African-Americans) factors. Multivariate logistic regression was used to address the study objective.

RESULTS

Approximately 1 in 5 (20.2%) who used CAM in the past 12 months used CAM to treat a specific condition. Ten of the 15 CAM modalities were used primarily for treatment by African-Americans. CAM for treatment was significantly (P<.05) associated with the following factors: graduate education, smaller family size, higher income, region (northeast, midwest, west more likely than south), depression/anxiety, more physician visits, less likely to engage in preventive care, more frequent exercise behavior, more activities of daily living (ADL) limitations, and neck pain.

CONCLUSIONS

Twenty percent of African-Americans who used CAM in the past year were treating a specific condition. Alternative medical systems, manipulative and body-based therapies, and folk medicine, prayer, biofeedback, and energy/Reiki were used most often. Health care professionals should routinely ask patients about the use of CAM, but when encountering African-Americans, there may be a number of factors that may serve as cues for further inquiry.

Attitudes and knowledge toward natural products safety in the pharmacy setting: an Italian study

The lack of a professional supervision may expose consumers of natural products to risks; pharmacists play an important role in giving information about these substances. A survey was designed to investigate the attitudes and knowledge of consumers and pharmacists toward the safety of natural products. Twenty-three pharmacies participated in the project. On the basis of a pre-structured 17-item questionnaire, face-to-face interviews were conducted with consumers buying a natural product over a 6-month period. A further 8 items had to be compiled by pharmacists about the purchased product. During the study period, 1420 interviews were carried out. The most frequently purchased products were echinacea, propolis, garlic, guggul, ginkgo, liquorice, ginseng, glucomannan, guarana, valerian, and passionflower; 71.8% of consumers reported to have been taking conventional medicines along with natural products. Some (3.9%) referred to adverse effects in the last year: allergic reactions after cartilage of shark, propolis and thyme; anxiety after hypericum; hypotension and tachycardia after a mix containing chamomile, valerian and melissa; pyrosis and stomach-ache after laxative-depurative herbs. Pharmacists referred to some adverse effects observed in the past in relation to the products bought by consumers involved in this study. Findings from this study demonstrate that in general consumers need information on herbal safety and pharmacists are more likely to answer correctly about the use of herbs rather than about cautions, adverse effects and interactions.

Patient Disclosure about Herb and Supplement Use among Adults in the US

Analyses of 2002 National Health Interview supplement on complementary and alternative medicine (NHI%AM) indicate that approximately 38 million adults in the US (18.9% of the population) used natural herbs or supplements in the preceding 12 months, but only one-third told their physician about this use. The objectives of this study are: (i) to determine subpopulation rates of patient-physician communication about herbal product and natural supplement use and (ii) to identify the relative influence of patient factors and interaction factors associated with patient-physician communication about herb and supplement use. Logistic secondary analysis was done by using the complementary and alternative medicine supplement of the 2002 National Health Interview Survey. Subjects were a random stratified sample of US adults who used herbs in the past 12 months (n = 5 196) and self-reported rates of disclosure to physicians about herb and supplement use. Results show that disclosure rates were significantly lower for males, younger adults, racial and ethnic minorities and less intensive users of medical care. Across subpopulations, disclosure was the exception rather than the norm. Given the potential risks of delayed or inappropriate treatment and adverse drug reactions and interactions, physicians should be aware of herb and supplement use and counsel patients on the potential risks and benefits of these treatments.

Patient-Physician Communication Regarding Use of Complementary Therapies During Cancer Treatment

It is estimated that as many as 80% of adult cancer patients use at least one form of Complementary and Alternative Medicine (CAM) during or after conventional treatment. Studies of physician-patient communication about the use of CAM have concluded that patients frequently do not tell their oncologists about their use of CAM and physicians consistently underestimate the numbers of their patients using CAM. The purpose of this multi-site study was to assess newly diagnosed cancer patients' and oncologists' communication practices with regard to complementary therapies. Patients (106 breast and 82 prostate) indicated which of 45 complementary therapies they were using while physicians at their institutions indicated which they supported. It is noted that, although we use the popular acronym "CAM" all patients surveyed were receiving conventional medical treatment. Thus, the survey addressed complementary therapies only. A large majority (84%) indicated they were using at least one therapy with the most popular being exercise, vitamins, prayer, and nutritional supplements. Surprisingly, the oncologists surveyed were generally enthusiastic and supportive of patients' use of complementary therapies. In addition to those therapies popular with patients, at least half the physicians supported massage, journal writing, support groups, acupuncture, biofeedback, and art therapy. However, discussions of CAM are relatively rare and most likely to be initiated by patients. When the topic is discussed, both patients and doctors say it usually enhances their relationship. Implications for CAM program development and oncology professionals' roles in patient education regarding complementary therapies are presented.

Phytotherapic compounds: the consumer-pharmacist relationship

Pharmacists play an important role in providing information about natural products and in preventing risks related to these substances, particularly with respect to interactions with conventional drugs. For these reasons, a survey was specifically designed to investigate the quality of self-care counselling by pharmacists on phytotherapy. Twenty-three pharmacy stores took part in the project. Face-to-face interviews, using a pre-structured questionnaire, were undertaken by trained pharmacists to consumers buying a herbal product. The questionnaire included socio-demographic data and 17 items designed to elicit information regarding the reason of consumption, product knowledge, relationship/communication with healthcare providers, level of satisfaction, concurrent drug use and adverse reactions. The collection of interviews started in November 2006 until April 2007. From the analysis of 1420 questionnaires, it is evident that herbal use is increasing in Italy: 12% of our interviewees were buying a herbal product for the first time. The present survey highlights the favourable perception of efficacy of phytotherapic compounds by the pharmacy's consumers, who consider this healthcare modality to be an important and effective way to promote health/wellness and disease management as well as being safer overall than conventional drugs. Moreover, findings from this study demonstrate that pharmacists are more likely to answer correctly about the uses of herbal medicines than about drug interactions, adverse drug effects and cautions about these products.

Deconstructing an adaptogen: Eleutherococcus senticosus

The dried roots and rhizomes of Eleutherococcus senticosus (Araliacaea) plant are used in various preparations, primarily for its "adaptogenic" properties. An adaptogen supports health and prevents disease in both sick and healthy individuals through nonspecific effects, which neutralize various environmental and physical stressors while remaining relatively safe and free of side effects. The term "adaptogen," which has not been well defined scientifically, undermines the need for increased inquiry and research into the many promising effects of this herb. The primary clinical applications, pharmacology, evidence of efficacy, contraindications, drug interactions, and current clinical and scientific research are also reported.

Warfarin and its interactions with foods, herbs and other dietary supplements

Despite its complex pharmacokinetic and pharmacodynamic profile, warfarin is still one of the most widely used oral anticoagulant agents. Attaining optimal anticoagulation with this agent is clinically challenging in view of its many food and drug interactions. Inappropriate anticoagulation control can expose patients to an increased risk of bleeding or thromboembolic complications, due to over and underanticoagulation, respectively. Fluctuations in dietary vitamin K intake can have a significant effect on the degree of anticoagulation in patients treated with warfarin. In addition, the explosion in use of various dietary supplements and herbal products can lead to undesired outcomes on anticoagulant levels. The aim of this review is to discuss the scope and the potential clinical impact of the most commonly reported food, dietary supplement and herbal interactions with warfarin therapy. Practical steps for patients and providers to minimise these interactions are highlighted.

Pharmacists' attitudes and awareness towards the use and safety of herbs in Kuwait

OBJECTIVES

The purpose of this study was to investigate the knowledge and attitudes among pharmacists in Kuwait towards the use of herbs.

METHODS

Self-administered questionnaire was designed as the study instrument and distributed among 100 qualified pharmacists working in government and private pharmacies in Kuwait.

RESULTS

The mean age was 34.2 (SD=7.5) years. About 51% of pharmacists reported they had used herbal therapy in their lifetime. The majority were interested in herbal information, and their herbal information came mainly from their previous classes during college. Although the pharmacists' knowledge about uses of selected herbs was good, their awareness about side effects of those herbs was modest. About 31% of the pharmacists did not have enough information about potential interactions between herbs and conventional medicines.

CONCLUSION

Herbal information is needed for pharmacy students as part of the Pharmacy College curriculum. Continuing education programs for practising pharmacists about the safety of different herbal products should be established in Kuwait.

Use of Herbal Supplements and Vitamins in Plastic Surgery: A Practical Review

LEARNING OBJECTIVES

After studying this article, the participant should be able to: 1. Explain what governmental regulations control the labeling and distribution of herbal supplements. 2. List the more commonly used supplements and their reported benefits. 3. List the possible postoperative complications from consumption of the more commonly used herbal supplements. 4. Explain the preoperative management of patients using herbal supplements. 5. Know additional resources to consult when unanswered questions arise.

BACKGROUND

The American public spends over $5 billion per year on herbal supplements, and approximately 20 percent of all Americans use prescription medications concurrently with herbal supplements. As the number of people who take alternative medicines rises, there is growing awareness among health care providers of the need to become educated and to educate their patients on the effects that such supplementation may have on their health. As plastic surgeons, we have an added responsibility to become informed because of potential adverse interactions with other medications and anesthesia in the elective surgical patient.

METHODS

Literature regarding commonly encountered herbal supplements and vitamins was reviewed and summarized to include reported indications for use and potential adverse effects and interactions specific to the perioperative patient.

RESULTS

Abundant literature exists regarding herbal supplementation, but very little scientific evidence exists to advocate the use of the majority of supplements available on the market. In addition, little is known about the positive and negative interactions that these supplements are capable of producing, and those interactions that are known are based on case reports.

CONCLUSIONS

With the lack of quality scientific studies to support the efficacy of most herbal products available and the limited regulation of these products by the government, health care providers are faced with a significant public health dilemma. This article provides a brief overview of information published on commonly encountered herbal supplements and vitamins taken by plastic surgery patients.

Complementary And Alternative Medicine (CAM) in Palestine: Use And Safety Implications

AIM

Utilization of complementary and alternative medicine (CAM) is exponentially rising. There are no published data available about the attitude and use of CAM in Palestine. The purpose of this study was to investigate the attitude, pattern of use, and reasons for CAM utilization among a random sample of people in north Palestine.

METHODS

A questionnaire was used to carry out the objective of the study. The questionnaire was distributed to a random sample of people in north Palestine during the month of October 2005. The questionnaire included three sections: demographic factors and attitude toward CAM, types of CAM encountered by the respondents in the last year, and reasons that motivated CAM use. Data collected from the returned questionnaire were coded and entered into the Statistical Package for Social Sciences program (SPSS) version 10 (SPSS Software, Inc., Chicago, IL).

RESULTS

72.8% of respondents have used at least one type of CAM in the last year. CAM users were mainly middle-aged, low-income, educated women. Herbal therapy, prayers, and honey were the most commonly utilized types of CAM. Respondents have used CAM mainly to treat respiratory and gastrointestinal disorders. Respondents have utilized CAM mainly because they believed that it is all natural and safe.

DISCUSSION AND CONCLUSIONS

CAM utilization in Palestine is very common. Some of the types of CAM used in Palestine are common elsewhere, whereas other types were unique to this area. The herbal products used by the respondents were mainly collected from nature. Safety of such products is questionable, and contamination cannot be ruled out. Awareness of potential adverse effects and proven benefits of various types of CAM needs to be raised.

A musculoskeletal model of low grade connective tissue inflammation in patients with thyroid associated ophthalmopathy (TAO): the WOMED concept of lateral tension and its general implications in disease

Background

Low level connective tissue inflammation has been proposed to play a role in thyroid associated ophthalmopathy (TAO). The aim of this study was to investigate this postulate by a musculoskeletal approach together with biochemical parameters.

Methods

13 patients with TAO and 16 controls were examined. Erythrocyte levels of Zn, Cu, Ca²⁺, Mg, and Fe were determined. The musculoskeletal evaluation included observational data on body posture with emphasis on the orbit-head region. The angular foot position in the frontal plane was quantified following gait observation. The axial orientation of the legs and feet was evaluated in an unloaded supine position. Functional propioceptive tests based on stretch stimuli were done by using foot inversion and foot rotation.

Results

Alterations in the control group included neck tilt in 3 cases, asymmetrical foot angle during gait in 2, and a reaction to foot inversion in 5 cases. TAO patients presented facial asymmetry with displaced eye fissure inclination (mean 9.1°) as well as tilted head-on-neck position (mean 5.7°). A further asymmetry feature was external rotation of the legs and feet (mean 27°). Both foot inversion as well as foot rotation induced a condition of neuromuscular deficit. This condition could be regulated by gentle acupressure either on the lateral abdomen or the lateral ankle at the acupuncture points gall bladder 26 or bladder 62, respectively. In 5 patients, foot rotation produced a phenomenon of moving toes in the contra lateral foot. In addition foot rotation was accompanied by an audible tendon snapping. Lower erythrocyte Zn levels and altered correlations between Ca²⁺, Mg, and Fe were found in TAO.

Conclusion

This whole body observational study has revealed axial deviations and body asymmetry as well as the phenomenon of moving toes in TAO. The most common finding was an arch-like displacement of the body, i.e. eccentric position, with foot inversion and head tilt to the contra lateral side and tendon snapping. We propose that eccentric muscle action over time can be the basis for a low grade inflammatory condition. The general implications of this model and its relations to Zn and Se will be discussed.

Perceived efficacy of herbal remedies by users accessing primary healthcare in Trinidad

Background

The increasing global popularity of herbal remedies requires further investigation to determine the probable factors driving this burgeoning phenomenon. We propose that the users' perception of efficacy is an important factor and assessed the perceived efficacy of herbal remedies by users accessing primary health facilities throughout Trinidad. Additionally, we determined how these users rated herbal remedies compared to conventional allopathic medicines as being less, equally or more efficacious.

Methods

A descriptive cross-sectional study was undertaken at 16 randomly selected primary healthcare facilities throughout Trinidad during June-August 2005. A de novo, pilot-tested questionnaire was interviewer-administered to confirmed herbal users (previous or current). Stepwise multiple regression analysis was done to determine the influence of predictor variables on perceived efficacy and comparative efficacy with conventional medicines.

Results

265 herbal users entered the study and cited over 100 herbs for the promotion of health/wellness and the management of specific health concerns. Garlic was the most popular herb (in 48.3% of the sample) and was used for the common cold, cough, fever, as 'blood cleansers' and carminatives. It was also used in 20% of hypertension patients. 230 users (86.8%) indicated that herbs were efficacious and perceived that they had equal or greater efficacy than conventional allopathic medicines. Gender, ethnicity, income and years of formal education did not influence patients' perception of herb efficacy; however, age did (p = 0.036). Concomitant use of herbs and allopathic medicines was relatively high at 30%; and most users did not inform their attending physician.

Conclusion

Most users perceived that herbs were efficacious, and in some instances, more efficacious than conventional medicines. We suggest that this perception may be a major contributing factor influencing the sustained and increasing popularity of herbs. Evidence-based research in the form of randomized controlled clinical trials should direct the proper use of herbs to validate (or otherwise) efficacy and determine safety. In the Caribbean, most indigenous herbs are not well investigated and this points to the urgent need for biomedical investigations to assess the safety profile and efficacy of our popular medicinal herbs.

Delirium in Older Adults With Cancer: Implications for Practice and Research

PURPOSE/OBJECTIVES

To provide a comprehensive review of the literature and existing evidence-based findings on delirium in older adults with cancer.

DATA SOURCES

Published articles, guidelines, and textbooks.

DATA SYNTHESIS

Although delirium generally is recognized as a common geriatric syndrome, a paucity of empirical evidence exists to guide early recognition and treatment of this sequelae of cancer and its treatment in older adults. Delirium probably is more prevalent than citations note because the phenomenon is under-recognized in clinical practice across varied settings of cancer care.

CONCLUSIONS

Extensive research is needed to formulate clinical guidelines to manage delirium. A focus on delirium in acute care and at the end of life precludes identification of this symptom in ambulatory care, where most cancer therapies are used. Particular emphasis should address the early recognition of prodromal signs of delirium to reduce symptom severity.

IMPLICATIONS FOR NURSING

Ongoing assessment opportunities and close proximity to patients' treatment experiences foster oncology nurses' mastery of this common exemplar of altered cognition in older adults with cancer. Increasing awareness of and knowledge delineating characteristics of delirium in older patients with cancer can promote early recognition, optimum treatment, and minimization of untoward consequences associated with the historically ignored example of symptom distress.

Investigation of the effects of herbal medicines on warfarin response in healthy subjects: a population pharmacokinetic-pharmacodynamic modeling approach

Systematic evidence regarding herb-drug interactions is lacking. This study investigated herb-drug interactions with warfarin. S-warfarin concentration and response (prothrombin complex activity) data from healthy subjects (n = 24) who received a single warfarin dose (25 mg) and either St John's wort, Asian ginseng, Ginkgo biloba, or ginger were analyzed using a population pharmacokinetic-pharmacodynamic modeling approach. The ratio of S-warfarin apparent clearance (CL/F) compared to control was 1.39 +/- 0.06 and 1.14 +/- 0.04 after St John's wort and Asian ginseng pretreatment, respectively. Other pharmacokinetic and pharmacodynamic parameters were unaffected. Coadministration of St John's wort significantly increased S-warfarin CL/F, whereas treatment with Asian ginseng produced only a moderate increase in CL/F. Ginkgo and ginger did not affect the pharmacokinetics of warfarin in healthy subjects. None of the herbs studied had a direct effect on warfarin pharmacodynamics. Studies in anticoagulated patients are warranted to assess the clinical significance of these herb-drug interactions.

Complementary and alternative medicines versus prescription drugs: perceptions of emergency department patients

BACKGROUND

The perceptions of emergency department (ED) patients towards complementary and alternative medicines (CAM) are poorly understood. We assessed these perceptions and compared CAM users with non-users, particularly regarding CAM safety and efficacy.

METHODS

This was an analytical, cross sectional survey of ED patients undertaken in a tertiary referral ED. A five point Likert scale evaluated patients' level of agreement with statements relating to CAM and prescription drugs.

RESULTS

Of 404 patients who were enrolled (participation rate 97.1%), 275 (68.1%; 95% confidence interval (CI) 63.2 to 72.5) were CAM users (had taken a CAM within the previous 12 months). There were 178 patients (44.1%, 95% CI 39.2 to 49.1) who agreed or strongly agreed that CAM are drug free, and there was no significant difference between CAM users and non-users (p = 0.77). There were 115 patients (28.5%, 95% CI 24.2 to 33.2) who agreed or strongly agreed that CAM are always safe to take with prescription drugs, and there were no significant difference between CAM users and non-users (p = 0.39). Significantly more CAM users agreed or strongly agreed that CAM are safe to take, can prevent people from becoming ill, allow people to be in charge of their own health, can treat the mind, body, and spirit, and are more effective than prescription drugs (p<0.01). Significantly fewer CAM users agreed or strongly agreed that prescription drugs are safe to take (p<0.001).

CONCLUSION

Considerable proportions of ED patients are CAM users yet are ignorant of the nature and potential toxicities of CAM. In addition, CAM users have significantly different perceptions of CAM and prescription drugs from non-users. The impact of these perceptions on clinical practice needs evaluation.

A survey of Chinese herbal medicine intake amongst preoperative patients in Hong Kong

We have surveyed, by means of a questionnaire, the preoperative use of traditional Chinese medicines in 259 adult Chinese patients admitted to a Hong Kong teaching hospital. The spectrum and use of herbal remedies differed from that reported by Western sources. Of those patients surveyed 90% used Chinese herbs on a regular daily basis in traditional soups and teas while 44% had consulted a traditional Chinese medicine practitioner in the last twelve months prior to admission, but mainly for health promotion (59%) and minor ailments (30%). Only 25% sought advice for their current illness and 13% were taking regular traditional Chinese medicines prior to admission. The ingredients were difficult to identify. Patients with cancer were more likely to use ling zhi (odds ratio 5.4). Female patients with reproductive problems were more likely to visit a traditional Chinese medical practitioner (odds ratio 2.6) and use ginseng (odds ratio 5.1). The anaesthetic implications of preoperative traditional Chinese medicine in keeping with Hong Kong practices need to be investigated, and appropriate anaesthetic guidelines should be developed.

Safety implications regarding use of phytomedicines

OBJECTIVE

Since the approach of the general population to phytomedicine is that the therapy therapy is natural and therefore safe, the aim of this study was to investigate the relationship between the use of herbal compounds, alone or in combination with traditional drugs, and the appearance of side-effects among a sample of Italian women.

METHODS

Our research was conducted over a 5-month period in the outpatient ambulatories of an urban university general hospital. The sample population consisted of women who were interviewed about phytotherapy use on the basis of a pre-structured questionnaire.

RESULTS

Among 1,063 women contacted, 1,044 completed the interview and 491 (47%) reported taking at least one herbal compound in the last year; 272 women (55.4%) consumed only phytomedicines, while 219 (44.6%) also took traditional drugs. Seventy-three different herbal products were used, 32 were consumed in association with traditional drugs. Forty-seven of 491 (9.6%) women reported side-effects, 22 after taking only phytomedicines (8.1%), 25 in combination with traditional drugs (11.4%). The observed adverse manifestations included the following: gastrointestinal after dandelion, propolis or fennel; cardiovascular after liquorice, ginseng, and green tea; dermatological after propolis, thyme, arnica, and passionflower; and neurological after guarana and liquorice. Drugs taken in association and potentially involved in adverse reactions were NSAIDs, antibiotics, benzodiazepines, antihypertensives and oral contraceptives. In some cases (n=5), side-effects were so serious to justify an admission to the hospital. In 29/47 of cases (61.7%), the adverse reaction was not communicated to the doctor.

CONCLUSIONS

Our data confirm that herbal products are largely taken on a self-treatment basis, and users have the conviction that these therapies are natural and therefore safe.

A gap between acceptance and knowledge of herbal remedies by physicians: the need for educational intervention

Background

The unprecedented global increase in the use of herbal remedies is set to continue apace well into the foreseeable future. This raises important public health concerns, especially as it relates to safety issues including adverse effects and herb-drug interactions. Most Western-trained physicians are ignorant of the risks and benefits of this healthcare modality and assessment of acceptance and knowledge would identify appropriate intervention strategies to improve physician-patient communication in this area.

Methods

A cross-sectional survey was done using an interviewer-administered pilot tested de novo questionnaire at six public hospitals in Trinidad between May–July 2004. The questionnaire utilized weighed questions to quantify acceptance (maximum score = 14 points) and knowledge (maximum score = 52 points). Acceptance and knowledge scores were analyzed using the ANOVA and Tukey's tests.

Results

Of 192 physicians interviewed, most (60.4%) believed that herbal remedies were beneficial to health. Respondents had relatively high acceptance levels (mean = 5.69 ± 0.29 points or 40% of total possible score) and poor knowledge (mean = 7.77 ± 0.56 points or 15% of total possible score). Seventy-eight physicians (40.6%) admitted having used herbs in the past, and 60 of these (76.9%) were satisfied with the outcome. Although 52 physicians (27.1%) recommended the use of herbs to their patients only 29 (15.1%) were able to identify at least one known herb-drug interaction.

Conclusion

The use of herbal remedies is relatively high in Trinidad, as throughout the world, and most patients self-medicate with or without the knowledge of their attending physician. Surprisingly, we demonstrated relatively high acceptance levels and use of herbs among physicians in Trinidad. This interesting scenario of high acceptance levels and poor knowledge creates a situation that demands urgent intervention. We recommend educational intervention to narrow the gap between acceptance and knowledge so that physicians would be adequately equipped to communicate with their patients on this modality. The integration of herbal medicine into the curriculum of medical schools, continuing education programs and the availability of reputable pharmacopoeias for referencing at public health institutions are useful instruments that can be used to close this gap and promote improved physician-patient communication.

Herb and supplement use in the US adult population

BACKGROUND

Research on the scope of use and factors associated with herbal medicine use is limited.

OBJECTIVES

The aims of this work were to assess national usage patterns, reasons for use, and the perceived efficacy of herbal products and dietary supplements.

METHODS

This was a secondary analysis of the complementary and alternative medicine (CAM) supplement to the 2002 National Health Interview Survey (NHIS), conducted by the National Center for Health Statistics (NCHS). Participants were asked whether they had used natural herbs for their own health and treatment. Those who responded yes were compared with those who responded no. Supplement users were asked whether they had used any of 36 specific herbs or nonherbal dietary supplements (eg, glucosamine, fish oil, bee pollen), how important the use of CAM treatment was to them, whether they had seen a CAM provider, and whether they had informed a conventional medical provider about their use. NCHS weights, derived from Decennial Census data, were used to calculate national prevalence estimates. Group comparisons of herbal use were conducted with the Wald x(2) test.

RESULTS

A total of 31,044 adults participated in the 2002 NHIS CAM survey; 632 were omitted from analyses due to incomplete information. In all, 5787 adults said they had used herbs or supplements during the previous 12 months, of whom 57.3% said they used these products to treat specific conditions. Based on these responses, an estimated approximately 38.2 million adults in the United States used herbs and supplements in 2002. More than half of all users said that herbs and natural products were important to their health and well-being. Use rates were higher for women than men (21.0% vs 16.7%; P < 0.001); adults aged 45 to 64 years (P < 0.001 vs other age groups); those of multiple races (32.2%), Asians (24.6%), or American Indians or Alaskan natives (21.9%) rather than whites (19.1%) or blacks (14.3%) (effect of race, P < 0.001); residents of the western United States (effect of region, P < 0.001), and college graduates (25.3% vs 10.4% among those who did not graduate high school; effect of education, P < 0.001). Only 33.4% told a conventional health care provider about their herb or supplement use use.

CONCLUSION

Herb and natural supplement use was widespread in the US adult population in 2002, according to data from the NHIS CAM survey, despite the fact that few participants informed their conventional health care providers about such use.

The potential impact of the use of homeopathic and herbal remedies on monitoring the safety of prescription products

The purpose of this paper is to explore the possibility that adverse reactions and drug interactions arising from the use of homeopathic and herbal medicines could lead to confusion when adverse reactions to conventional medicines are reported. An extensive literature review was conducted on the occurrence of adverse reactions and drug interactions following the use of homeopathic or herbal remedies, and the potential for these to confound adverse event reporting to conventional medicines considered. The survey demonstrates the potential for herbal remedies and homeopathic products, to produce adverse drug reactions or drug interactions, and shows the scope for potential for confusion with those arising from conventional medicines. There is a need for greater awareness that adverse reactions apparently due to a conventional medicine, might in reality be due to a herbal medicine or a drug interaction between a herbal medicine and a conventional drug, particularly when a health professional is unaware of the extent of a patient's self-medication with alternative therapies.

Potential for interaction of kava and St. John's wort with drugs

The present interest and widespread use of herbal remedies has created the possibility of interaction between them and pharmaceutical drugs if they are used simultaneously. Before the recent reports of apparent hepatotoxicity associated with its use, kava (Piper methysticum Forst. F.), was one of the top 10 selling herbal remedies in Europe and North America. This adverse effect was not previously encountered with the traditional beverage which was prepared as a water infusion in contrast to the commercial products which are extracted with organic solvents. Kavalactones, the active principles in kava, are potent inhibitors of several of the CYP 450 enzymes, suggesting a high potential for causing pharmacokinetic interactions with drugs and other herbs which are metabolized by the same CYP 450 enzymes. Furthermore, some kavalactones have been shown to possess pharmacological effects, such as blockade of GABA receptors and sodium and calcium ion channels, which may lead to pharmacodynamic interactions with other substances which possess similar pharmacological proprieties. St. John's wort (Hypericum perforatum L.), used extensively for the treatment of mild to moderate clinical depression, has long been considered safer than the conventional pharmaceutical agents. However, its ability, through its active constituents hypericin, pseudohypericin and hyperforin, to induce intestinal P-glycoprotein/MRD1 and both intestinal and hepatic CYP3A4 enzyme, could markedly reduce the distribution and disposition of their co-substrates. In addition, St. John's wort is a potent uptake inhibitor of the neurotransmitters serotonin, norepinephrine and dopamine all of which have a role in mood control. Consequently, the very real potential for a pharmacodynamic interaction between the herb and pharmaceutical drugs which share this mechanism of action and, like St. John's wort, are used for mood elevation. However, presently there is very little evidence to substantiate actual pharmacokinetic and/or pharmacodynamic interaction between drugs and kava or St. John's wort. This review provides a brief overview of the existing data on interactions of kava and St. John's wort with pharmaceutical agents and as a result reveals the urgent need for detailed investigations to identify clinically significant interactions for these herbal remedies that have the potential to cause adverse effects.

Adverse drug interactions and reactions in dermatology: current issues of clinical relevance

This article highlights several adverse drug interactions and reactions relevant to current dermatologic practice. Absorption interactions between drugs and compounds containing polyvalent cations, potential interactions between herbal and conventional medicines, the meaning of sulfa allergy, and adverse cutaneous reactions caused by epidermal growth factor receptor inhibitors are discussed.

Herb-drug interactions: an overview of the clinical evidence

Herbal medicines are mixtures of more than one active ingredient. The multitude of pharmacologically active compounds obviously increases the likelihood of interactions taking place. Hence, the likelihood of herb-drug interactions is theoretically higher than drug-drug interactions, if only because synthetic drugs usually contain single chemical entities. Case reports and clinical studies have highlighted the existence of a number of clinically important interactions, although cause-and-effect relationships have not always been established. Herbs and drugs may interact either pharmacokinetically or pharmacodynamically. Through induction of cytochrome P450 enzymes and/or P-glycoprotein, some herbal products (e.g. St John's wort) have been shown to lower the plasma concentration (and/or the pharmacological effect) of a number of conventional drugs, including cyclosporine, indinavir, irinotecan, nevirapine, oral contraceptives and digoxin. The majority of such interactions involves medicines that require regular monitoring of blood levels. To date there is less evidence relating to the pharmacodynamic interaction. However, for many of the interactions discussed here, the understanding of the mechanisms involved is incomplete. Taking herbal agents may represent a potential risk to patients under conventional pharmacotherapy.

Interactions between herbal and conventional medicines

Herb-drug interactions are subject to much interest at present, but for various reasons reports may be unreliable or unsubstantiated. Herbal medicines are variable in composition and quality, which may affect their interaction profile as well as the reliability of reports concerning them. In this review, clinical and experimental reports have been collated, evaluated and summarised, and the theoretical and clinical evidence presented. There is an explanation of the particular issues involved with herbal medicines as compared with conventional drugs, and reasons why comparisons may or may not be valid, which is intended for those without specialist experience in herbal products. It has become apparent that only a few herbal drugs have so far been cited in interaction reports, for example St John's Wort, Ginkgo biloba, Dan Shen, liquorice, Ma huang and garlic, and that the main drugs involved are those which are already susceptible to interactions with many other conventional drugs, such as warfarin, protease inhibitors and anti-cancer drugs. An attempt has been made to put the matter into perspective and recommendations have been given for health professionals to advise or develop strategies to safeguard patients, without resorting to speculation or scaremongering.

New developments in antidepressant therapy

Depression is an overwhelmingly common problem in the United States. It is not only life threatening, but also costly, both personally and financially. Following a brief overview of depression, this article presents a variety of treatment modalities. Advantages and dis-advantages of each intervention are explored along with suggestions for evaluating current and future advances in treatment options.

Safety and side effect profile of fluoxetine

Fluoxetine was the first selective serotonin re-uptake inhibitor to be widely available for treatment of depression and numerous other neuropsychiatric disorders. Its attributes have been described in numerous scientific papers, and it has been the subject of a considerable volume of lay press. Fluoxetine is generally safe and well-tolerated. Common adverse events reported with the recommended dose of 20 mg/day are referable to the gastrointestinal system and the nervous system. The approved dose range is up to 80 mg/day, and when higher doses are used, adverse events are more common. The long half-life of fluoxetine and its active metabolite essentially preclude a withdrawal phenomenon. It is an inhibitor of cytochrome P450 (CYP) 2D6 and other CYP enzymes, which increases the potential for drug interactions. However, most of these are not clinically important. The purpose of this review is to provide an overview of some of the most important information related to safety and side effects of this drug.

Use and toxicity of complementary and alternative medicines among emergency department patients

OBJECTIVE

To determine the prevalence and type of complementary and alternative medicines (CAM) used by ED patients, to identify patient subgroups more likely to use CAM, the conditions for which they were taken, and the prevalence of side-effects and toxicity associated with CAM use.

METHODS

This was an analytical cross-sectional survey of patients at a large tertiary referral ED. Consenting patients completed a specifically designed study questionnaire, in their preferred language if required. Information was collected on CAM use on the day of presentation and within the previous week and previous year.

RESULTS

Four hundred and four patients were enrolled (participation rate 97.1%). Fifty (12.4%, 95% CI 9.4, 16.1) patients had taken a CAM on the day of presentation, 203 (50.2%, 95% CI 45.3, 55.2) within the previous week and 275 (68.1%, 95% CI 63.2, 72.5) within the previous year. CAM users were significantly younger, better educated and more likely to be female than non-CAM users (P < 0.01). 103 different CAM had been taken for a wide variety of reasons. Side-effects were experienced in 53 of the 1182 CAM courses taken (side-effect rate of 4.5%). One patient presented suffering specifically from CAM toxicity.

CONCLUSION

Complementary and alternative medicines are used by a considerable proportion of ED patients. The potential for side-effects, toxicity and interaction with traditional medication indicates the need for consideration of CAM use in patient assessment.