herbdrug Common interactions: What you should know

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1 Common herbdrug interactions: What you should know By Susan Simmons Holcomb, ARNP-BC, PhD P atients take herbal medications for many reasons. Direct-to-consumer advertising may promise improved mood, memory, and weight loss, or improved general well-being. Herbal medications may seem easier to access and less costly than arranging an appointment with a healthcare provider, hassling with insurance companies, and obtaining a prescription that needs to be filled. With the increased use of complementary and alternative medicine (CAM) therapies, APNs need to know all medications (prescribed and over-thecounter), supplements, herbal products, and vitamins that the patient is taking. APNs must also have the knowledge and resources available to determine herb-drug interactions as well as adverse reactions of herbal products that may be deleterious to patients. To examine all potential herb-drug interactions is well beyond the realm of this article; providing an overview of more commonly used herbs is the goal. Often, individuals utilize herbal products for weight loss, fatigue, insomnia, and depression. 1,2 Examples of herbal products used for each of these conditions will be discussed along with potential herb-drug interactions. Background on CAM In a landmark study in 1998, Eisenberg and colleagues found that 50% of patients used CAM The Nurse Practitioner May

2 therapies and between 60% to 70% of those patients did not tell their healthcare providers of such use. 3 In 2007, the National Center for Complementary and Alternative Medicine (NCCAM) published a study showing that 40% of patients are likely to use CAM therapies, and women use them more commonly than men. 2 Women ages 50 to 59 showed the highest use of CAM therapies, and women ages 30 to 39 were the second-highest users. The study also found that whites use CAM therapies more often than African-Americans or Hispanics. In addition, the study showed that use of CAM therapies by teens is on the rise with 79% claiming to use at least one type of CAM therapy, most commonly St. John s Wort and herbal weight loss products. Herbal preparations are considered dietary substances rather than medications, so purity and efficacy do not have to be proven. Herbal safety Herbal safety not only pertains to the actual herb itself and the part of the plant used, but also to its growing conditions. As with all crops, environmental factors influence crop growth and safety. Growing factors may include the part of the world where the herb is grown, nature s influence, soil, human influence, and harvesting. 5 Growing and harvesting conditions of the herb affect the purity and potency. The soil and other possible contaminants may contain heavy metals such as arsenic, lead, cadmium, or mercury, which are toxic and have often been found in Ayurvedic herbal medicines. Purity is also affected by the use of chemicals, such as pesticides and fungicides, but also by the lack of such agents if the plant is contaminated with pests, fungi, or bacteria that may cause disease. 5,6 Standardization can help promote safety by ensuring that the contents of herbal medicines will be labeled accurately. Standardization is based on the part of the plant used, growing and harvesting conditions, and storage and manufacturing conditions. 5 Other concerns with herbal medications involve the active ingredients of the herbal preparation. Because herbal preparations are considered dietary substances rather than medications, purity and efficacy do not have to be proven. 4 In 1994, the Dietary Supplement Health and Education Act was passed, which stated that over-the-counter herbals were presumed safe as dietary supplements and therefore did not require safety or efficacy data.in 1998,the FDA added regulations for dietary supplements stating that the manufacturer could not claim that the supplement produced an effect on the structure or function of the body. If a claim is made, the product is considered a drug and must undergo the same regulations as other medications to prove safety and efficacy. The United States Pharmacopeia will soon be listing commonly used herbal supplements in an effort to address herbal safety. When an adverse reaction or safety concern occurs with herbals, it is reported to the FDA, specifically the Center for Food Safety and Applied Nutrition Adverse Event Reporting System. 2,5 Specific herbal safety issues include interference with lab testing, toxicity, and herb-drug interactions. Chan Su, for example, is an herb used for pain that can cause cardiac dysrhythmias and can also falsely elevate digoxin levels. St. John s Wort decreases digoxin, theophylline, and cyclosporine levels. Abnormal test results may also be due to herb toxicity, such as liver toxicity seen with Kava use, which causes an increase in liver function tests. 7 Herb toxicity can affect all major systems, including cardiovascular, hepatic, renal, neurological, and hematological. Fortunately, herb-drug interactions are less frequent and less serious than drug-drug interactions; however, they still occur. APNs should be familiar with the most commonly used herbs as well as the most common interactions. 5 Herbs generally pose less of a threat because they are of weaker potency than drugs. However, as previously mentioned, some herbal preparations have been laced with an actual drug which leads to increased adverse reactions and potential for herb-drug interactions. Herbal interactions are based on active ingredients in the herb which may be numerous for the individual herb or because the herb is in a multiherbal mix. Both drugs and herbals are metabolized by the cytochrome P-450 (CYP450) enzyme system of the liver, increasing the potential for herb-drug interactions. 5 Just as metabolism of herbs may be similar to drugs, pharmacokinetics may also be similar. Herbs may have an affinity for the same site of action as a drug. In cases where the drug and herb are taken together, synergism may increase the level of the drug, which could enhance not only the effect of the drug, but also the potential for adverse reactions. 5 Weight loss Some of the more common herbs used for weight loss include ephedra, chaparral, bitter orange, and Hoodia. Weight loss herbs are usually used to speed up metabolism. They 22 The Nurse Practitioner Vol. 34, No. 5

3 are thermogenic and are mild diuretics. Many have properties similar to caffeine. Ephedra Probably the most well-known weight loss herb is Ephedra sinica, also known as Ma huang or epitonin. Ephedra is considered an herbal amphetamine because of its stimulant mechanism of action, which is similar to caffeine. Due to its toxicity to the cardiovascular system, including stroke, ephedra use was banned in the United States in However, it may still be found in traditional Chinese herbal medications, herbal teas, and in products available online. Ephedra is also considered potentially toxic to the neurological, gastrointestinal, and endocrine (thyroid) systems Numerous herb-drug interactions can occur with ephedra, especially when taken in conjunction with cardiac, neurologic, and respiratory medications (see Examples of herb-drug interactions). Use of ephedra with these medications may lead to dysrhythmias, hypertension, psychosis, or anxiety, and may negate the effect of the allopathic medication Chaparral Like ephedra, chaparral s mechanism of action is similar to caffeine. Chaparral may also have a mild diuretic effect and can act as an energy booster and appetite suppressant. 10 Its botanical name is Larrea tridentate and it is also known by the common names creosote bush and greasewood. There are no known herb-drug interactions with chaparral; however, it is considered unsafe due to its potential for toxicities. Toxicity can affect renal, hepatic, and neurological systems. It is also considered a carcinogenic substance. 10 Bitter orange Bitter orange has the botanical name Citrus aurantium and is known by the common names of Seville orange, sour orange, and zhi shi. 10,11 The mechanism of action of bitter orange is similar to ephedra, potentially leading to cardiovascular and neurologic toxicity, especially when combined with other stimulants such as caffeine. The main herb-drug interaction is with monoamine oxidase inhibitors (MAOI). Hoodia Hoodia gordonii is the botanical name for Hoodia, also known as Kalahari cactus and xhoba. Hoodia s mechanism of action is unknown, but the San (Bushmen) of the Kalahari Desert in South Africa used it to decrease appetite and thirst during long hunts. In 1963, researchers began studying Hoodia as an appetite suppressant. The ingredient p57 was extrapolated and later was determined to suppress the appetite. P57 is a steroidal glycoside, which may work on hypothalamic cells to signal satiety 10,000 times more intensely than glucose. Satiety can last several hours. 12,13 At this time, no known toxicity or herb-drug interactions are known. However, pharmaceutical research on the herb was abandoned due to potential hepatoxicity. Another problem with available Hoodia products are that up to 80% Some of the more common herbs used for weight loss include ephedra, chaparral, bitter orange, and Hoodia. may be counterfeit, and do not actually contain the plant. Advise patients not to use products that advertise Hoodia as one of the ingredients until the safety and efficacy of the product is determined. Fatigue As with weight loss, numerous herbs have been used for fatigue. Some of the more commonly used herbs include ephedra, ginkgo, schisandra, American and Asian ginseng, and gotu kola. Ginkgo The botanical name for ginkgo is Gingko biloba. Common names for ginkgo are numerous and include fossil tree, maidenhair tree, Japanese silver apricot, baiguo, bai guo ye, kew tree, duck-foot tree, and yinhsing. Ginkgo is a tree that has existed for 3,000 years. 5,10,14-17 There are at least 40 different chemicals identified in ginkgo, each possibly contributing to its mechanism of action. 5,10,14-17 Of the chemicals identified, the most commonly known ones include flavonoids, terpenoids, flavones, catechins, sterols, and organic acid. Flavonoids are antioxidants that may also be neruro and amyloid protective. Terpenoids have anti-inflammatory, antiplatelet aggregation and smooth muscle relaxation properties. Gingko components may stimulate endothelium-derived relaxing factors and nitric oxide and may be important in BP management. Acetylcholine release in the brain is stimulated by ginkgo, which may improve short- and long-term memory, dementia, and fatigue. Ginkgo is generally considered safe. However, uncooked seeds contain ginkgotoxin, which can induce seizures, and The Nurse Practitioner May

4 Examples of herb-drug interactions 5,7,10,13,17 Herb Drug Potential interaction Ephedra Antiarrhythmics Dysrhythmias Antihypertensives Antiseizures MAOIs Theophylline Antidepressants Benzodiazepines Halothane Caffeine Cardiac glycosides Oxytocin Reduce effect of drug Reduce effect of drug Hypertension Dysrhythmias Anxiety, psychosis Reduce effect of drug Dysrhythmias Dysrhythmias, anxiety, hypertension Dysrhythmias Hypertension Bitter orange MAOIs Tachycardia, hypertension Ginkgo Anticoagulants Nonsteroidal anti-inflammatory drugs Antithrombics Tricyclics Antiseizure Seizures Seizures Ginseng Furosemide May cause drug resistance Oral antidiabetic agents Anticoagulants Antithrombics Valerian 3-hydroxy-3-methylglutaryl-coenzyme Increases drug level A reductase inhibitors (Statins) Antifungals Fexofenadine Benzodiazepines Alcohol Increase sedation Opioids Increase sedation Anticoagulants Potential to increase drug effect Kava Antiparkinson Decreases effect of drug Benzodiazepines Barbiturates Alcohol Increases sedation Antidepressants Chamomile Anticoagulants Potential to increase effect of drug Lavender No interactions known Passion flower CNS depressants Lemon balm Thyroid replacement Reduce effect of drug St. John s Wort Statins Tricyclic antidepressants Warfarin Nifedipine Cyclosporine Oral contraceptives (continued) The Nurse Practitioner May

5 Examples of herb-drug interactions 5,7,10,13,17 (continued) Herb Drug Potential interaction St. John s Wort (cont) Antiretroviral protease inhibitors Theophylline Digoxin Beta-2 agonists Benzodiazepines Sulfa Tetracycline Piroxicam Selective serotonin reuptake inhibitors Anesthetic agents Increased drug effect Increased drug effect Increased photosensitivity Increased photosensitivity Increased photosensitivity Induce psychosis Increase risk of serotonin syndrome May prolong anesthesia (anecdotal reports only) Siberian ginseng Digoxin With unstandardized eleuthero, increased drug level Nifedipine in large amounts, can result in death. Medications not recommended for concomitant use of ginkgo include anticoagulants, tricyclics, and antiseizure medications. Schisandra Schisandra is also known by the common names of gomishi, wu-wei-zi, and Chinese magnolia vine. Its botanical name is Schisandra chinensis. While it is unclear how schisandra can aid in fatigue, insomnia, stress, depression, or memory, it is understood have antioxidant and anti-inflammatory properties. 10 Schisandra is generally considered safe but is contraindicated in patients with seizure disorders and those who are pregnant. It has been found to have potential herb-drug interactions with barbiturates, amphetamines, and caffeine. American and Asian ginseng The botanical names for the ginsengs are Panax quinquefolius for American ginseng and Panax ginseng for Asian ginseng. Common names for American ginseng include Sang and Man root. Asian ginseng is also known as Chinese ginseng, Korean ginseng, and ren shen. It is unknown how the ginsengs work to help reverse fatigue, but it is thought to be related to ginsenoside stimulation of the central nervous system (CNS). Ginseng may also inhibit platelet aggregation. In general, ginseng is considered nontoxic although large amounts may lead to overstimulation of the CNS and cardiovascular systems. Ginseng should be avoided in patients 26 The Nurse Practitioner Vol. 34, No. 5 with hypertension, psychiatric disorders such as schizophrenia and bipolar disorder, and in cardiovascular disease. Ginseng should also be avoided in poorly controlled diabetic patients and women with estrogen-positive cancers. Herbdrug interactions include anticoagulants and antithrombic agents. 5,10,15,17 Gotu kola Gotu kola has the botanical name Centella asiatica.common names for gotu kola include Indian pennywort and Brahmi. Gotu kola is considered safe and has been used as a beverage in Asian countries for years. 10 No herb-drug interaction is apparent, but it is thought to possibly interact with anxiolytics. Gotu kola's mechanism of action in reversing fatigue is unknown. Insomnia Herbal products used for insomnia include valerian, kava, chamomile, skullcap, lavender, passion flower, lemon balm, and hops. Valerian Valerian is also known as all-heal and garden heliotrope, and its botanical name is Valeriana officinalis. Valerian s mechanism of action seems to be similar to benzodiazepines due to numerous constituents.valerenic acid may increase gamma-aminobutyric acid (GABA) activity by inhibiting its breakdown. It also has 5-hydroxytryptophan (5-HTP) activity, which is important for sleeping.

6 Valerian is considered safe for short periods of time. However, it is prudent to monitor liver function tests periodically while the patient is taking valerian. There is also a potential contraindication for valerian use in patients with schizophrenia or bipolar disorder. Valerian may have numerous herb-drug interactions via possible inhibition of the CYP450. It also interacts with alcohol and opiates. 2,5,10,15,18,19 Kava The botanical name for kava is Piper methysticum and common names include ava, awa, kawa, and yagna. Kava resins are thought to induce sleep. Kava also possesses GABA activity, known to promote sleep. In a 2003 Cochrane review, kava was the only herb found to have anxiolytics effects greater than placebo. Numerous herb-drug interactions are known with kava. Kava is also known to be extremely hepatoxic and should not be used. It may also increase suicide potential in those with severe depression. 2,5,10,18,20 Chamomile Chamomile is known by numerous names that tend to include the country or region the herb is grown common, true, wild, sweet, English, German, Hungarian, and Roman. The botanical name for chamomile is Matricaria recutita. The volatile oils are thought to have the sedating affect associated with chamomile. Chamomile is in the ragweed family, so patients with ragweed allergies should avoid this herb. There is no known toxicity and the German form has been used in pregnancy and with children. 18 Chamomile, however, may inhibit the CYP450 3A4 system similar to valerian and might interfere with anticoagulants. Skullcap Known also as mad dog and helmet flower, the botanical name of skullcap is Scutellania laterfolia. Skullcap has been used alone or in combination with other herbs for insomnia. The mechanism of action is unknown. There are no known herb-drug interactions. However, there is a chance for hepatotoxicity and this herb is not recommended. 10,18 Lavender Lavender is a commonly used herb also known as true lavender or English lavender. Its botanical name is Lavendula augustifolia. The volatile oils may be responsible for lavender s affect on insomnia. 10,18,21 There are no known herb-drug interactions for lavender. If used topically for an undetermined amount of time and undetermined dose, lavender may lead to gynecomastia in prepubescent boys. This adverse reaction is thought to be related to antiandrogenic activity, which has prompted research on the use of lavender for prostate cancer. There are at least 40 different chemicals identified in ginkgo, each possibly contributing to its mechanism of action. Passion flower Passion flower s botanical name is Passiflora incamata.its common names include apricot vine, water lemon, and maypop. Passion flower seems to possess benzodiazepine-like activity, which would explain its use for insomnia. Increased response with CNS depressants may occur when they are taken in conjunction with passion flower. Prior to 1978, passion flower was an over-the-counter sleep aid. It was removed from the shelves due to potential hepatotoxicity and again turned up on shelves as a dietary supplement. 2,10,18 This herb should be avoided. Lemon balm Lemon balm s botanical name is Melissa officinalis and it is also known commonly as balm, Melissa, and sweet balm. Its sedative properties may be related to its volatile oil. Lemon balm is often used in combination with other herbs for insomnia. There are no known toxicities for this herb, however it may interfere with thyroid medications. 10,18 Hops Humulus lupulus is the botanical name for hops, which is a member of the cannabis family. Its common names include European hops, common hops, and lupulin. Its sedative action is likely due to its volatile oils and hops are used to flavor beer. Numerous herb-drug interactions are known. The most common is that hops increase the sedative effect associated with drugs whose action or adverse reaction profile includes sedation. Hops may also induce CYP450 interactions. 10,18 By itself, hops is considered safe. Depression Numerous herbs have been used for depression. Some of the more common are St. John s Wort, American ginseng, The Nurse Practitioner May

7 Case study Mr. Jones comes to you to establish care and obtain a preoperative physical exam prior to total knee replacement surgery. He is a 65-year-old male with a history of hypertension, hyperlipidemia, arthritis, and depression. He states that he currently takes lisinopril, aspirin, citalopram, meloxicam, and simvastatin. You ask him about supplements and herbals and he says he takes a multivitamin. You ask him again if he takes any additional herbs or supplements. He finally admits that he takes ginkgo biloba daily to help with fatigue and valerian when he can t sleep. He did not want to tell you about these supplements because he thought you would not approve. He also admits to drinking a glass of wine nightly with dinner and a few glasses of wine or other alcoholic beverages if he and his wife go out on the weekends. He does not smoke and drinks two cups of coffee a day. You let Mr. Jones know how much you appreciate his honesty with you and explain to him the importance of alerting his healthcare providers to all substances that he takes because of the potential for interactions with each of them as well as the concern that some of them may affect his scheduled surgery. Mr. Jones has orders to discontinue any aspirin or nonsteroidal anti-inflammatory agents 1 week prior to surgery. You let him know that he will need to discontinue his aspirin and meloxicam at that time as well as both the ginkgo biloba and valerian, explaining to him that both of those herbs work on platelets, as do aspirin and meloxicam, potentially causing an increased risk in bleeding by interfering with clotting. After surgery, if Mr. Jones elects to restart ginkgo biloba and valerian, inform him of the other possible herb-drug interactions associated with his medications and these particular herbs. Because ginkgo biloba can increase the anticoagulant activity of aspirin and meloxicam, Mr. Jones should monitor for signs of bleeding such as increased bruising, bleeding gums, blood in the urine, or prolonged bleeding with injury or minor cuts. Mr. Jones should be advised to use caution when mixing valerian and alcohol since valerian increases the sedation associated with alcohol. Valerian can also increase the activity of simvastatin but how this will affect Mr. Jones cholesterol is unknown since he does not use valerian on a daily basis. He should also be advised that use of valerian on a short-term basis is probably safe, but that liver function tests should be followed, as with simvastatin. You encourage Mr. Jones to ask you, the pharmacist, or other healthcare providers questions regarding herbals and supplements before using them so that potential adverse reactions and herbdrug interactions can be discussed and potential problems prevented. Mr. Jones appreciates your concern and agrees. 28 The Nurse Practitioner Vol. 34, No. 5 ginkgo, gotu kola, lavender, schisandra, and Siberian ginseng. Most of these herbs have already been discussed. St. John s Wort St. John s Wort has the botanical name Hypericum perforatum and is also known by the common names touch and heal, goatweek, and Klamath weed. It is made up of numerous constituents, but it is thought that hypericin and hyperforin are responsible for its antidepressant activity. Hypericin inhibits monoamine oxidase, but this action is not considered significant. The more significant activity of both hypericin and hyperforin is their ability to inhibit serotonin reuptake. After continuous administration, the half-life extends from 6 hours to 1 to 2 days. St. John s Wort has been found to be effective for mild-to-moderate depression. 5,10,15,17,22-25 Numerous herb-drug interactions have been associated with St. John s Wort. It is capable of entering the CYP450 enzyme system. St. John s Wort also affects the transport of P-glycoproteins, which in turn influences the action of medications. Toxicity due to St. John s Wort is phototoxicity. Siberian ginseng The botanical name for Siberian ginseng is Eleutherococcus senticosus and it is known by the common names of eleuthero and ciwajia. Siberian ginseng is known for normalizing the adrenals, which helps to increase energy and possibly help to alleviate depression. Siberian ginseng may increase digoxin levels. There is no known toxicity with Siberian ginseng. 10,15,24 Patient counseling When obtaining a patient history, be sure to ask about all medications (prescribed and over-the-counter), herbals, and supplements that the patient is taking (see Case study). Patients may be reluctant to acknowledge their herbal use for fear their provider may be angry with them or lecture them. Patients may also think that dietary supplements do not have adverse reactions or interfere with allopathic medications. Many patients do not disclose their use of supplements and herbs because the healthcare provider never asks. 26,27 NPs should inquire about alcohol, caffeine, and illicit drug use. It is also important to explain the reason for knowing all of the substances that your patient uses is to better help them manage their health, including potential adverse reactions and interactions associated with medications, herbs, and supplements. If your patient also seeks medical care from a CAM practitioner, be sure to encourage them to share the same information with that practitioner. 27

8 Numerous resources are available to help you in your quest to know more about potential herb-drug interactions. Personal data assistant (PDA) programs are available where drugs, herbals, and supplements can be entered to quickly look at potential interactions as well as adverse reactions. Examples of PDA programs available include Epocrates ( and Pepid ( Other reputable publications are available as well. You can obtain information from the NCCAM, the Cochrane library, the Natural Medicine Comprehensive Database, and the Physician Desk Reference for Nonprescription Drugs, Dietary Supplements, and Herbs. The following are the national Web sites that can be used to find information on herbs: NCCAM ( National Institutes of Health, Office of Dietary Supplements ( FDA Office of Food Safety and Nutrition ( cfsan.fda.gov). Ask about herbs A recent study revealed that 77% of patients use CAM therapy including herbals. 16 In one study conducted in an ED, researchers discovered that over 70% of patients had not told their healthcare provider that they used herbal medications because the healthcare provider did not ask. 27 The researchers also found that the most common drugs associated with herb-drug interactions were aspirin and warfarin. In order to provide safe, effective, and adequate care to patients, APNs must begin to ask about all substances ingested including herbs, supplements, alcohol, and caffeine. When conducting a personal history and list of medications taken, the question should not only include, what medications do you take? Advise patients on potential adverse reactions, and herb-drug interactions. Women may look to herbs during pregnancy to calm side effects such as nausea, edema, and insomnia. In general, herbs, as with medications, should not be taken during pregnancy without determining the risk versus benefit ratio. Women who are pregnant should only use herbs when prescribed by a clinician with the proper knowledge and background in conjunction with an obstetrician and primary care provider. APNs need to stay current on CAM therapies, including herbal products and where to find additional information when needed, as well as encourage patients to always ask questions regarding CAM therapies. REFERENCES 1. National Center for Complementary and Alternative Medicine: CAM use high among adolescents htm. 2. Van der Watt G, Laugharne J, Janca A. Complementary and alternative medicine in the treatment of anxiety and depression. Curr Opin Psychiatr. 2008;21: Eisenberg DM, Davis RB, Ettner SL, et al. Trends in alternative medicine use in the United States : results of a follow-up national survey. J Am Med Assoc. 1998;280(18): National Center for Complementary and Alternative Medicine. Take charge of your health Lanca JA.Herbal medications: an evidence-based review. CME Resource.2007, course # Taylor DA. Botanical supplements: weeding out the health risks. Environ Health Persp. 2004;112(13):A750-A Dasgupta A. Review of abnormal laboratory test results and toxic effects due to use of herbal medicines. Am J Clin Pathol. 2003;120(1): National Center for Complementary and Alternative Medicine. Ephedra. Consumer Advisory sumeradvisory.htm. 9. National Center for Complementary and Alternative Medicine: Ephedra. Herbs at a Glance Kuhn MA, Winston D. Herbal Therapy and Supplements. Philadelphia, PA: Lippincott Williams & Wilkins; Scott GN. Problems with weight loss products. Pharmacist s Letter/Prescriber s Letter. 2006;22(1): (S(eftt2vv4dbkow1rij0nxnfrj))/pl/ArticleDD.aspx?cs=&s=PRL&pt=6&fpt =31&dd=220112&pb=PRL&searchid= #dd. 12. National Center for Complementary and Alternative Medicine. Herbs at a glance. Hoodia Sego S. Hoodia. The Clinical Advisor. 2008;2: National Center for Complementary and Alternative Medicine. Herbs at a glance. Ginkgo American Society of Anesthesiologists. Considerations for anesthesiologists: what you should know about your patients use of herbal medicines and other dietary supplements. cian.pdf. 16. Sego S. Ginkgo biloba. The Clinical Advisor. 2007;9: Woo TM. When nature and pharmacy collide: drug interactions with commonly used herbs. Adv Nurs Pract. 2008;7: Jellin JM. Natural medicines in clinical management of insomnia. Natural Medicines Comprehensive Database. (S(35ky2fuifc0ouqvjrfqd5dqz))/ce/ceCourse.aspx?s=ND&cs=&st=0&li=0 &pm=5&pc= National Center for Complementary and Alternative Medicine. Herbs at a glance. Valerian National Center for Complementary and Alternative Medicine. Herbs at a glance. Kava Lavender and tea tree oils can cause gynecomastia. Prescriber s Letter: Rumor vs Truth (S(eftt2vv4dbkow1rij0nx nfrj))/ pl/rumor.aspx?cs=&s=prl&fpt=31&rtid=155&searchid= Bancroft B. Menace in the mix. Adv Nurse Pract. 2007;12: National Center for Complementary and Alternative Medicine. Get the facts. St. John s Wort and depression. sjw-and-depression.htm. 24. Jellin JM. Natural medicines in the clinical management of depression. Natural Medicines Comprehensive Database. (S(cjrgxc55fq3oep55rrwracz0))/ce/ceCourse.aspx?s=ND&cs=&st=0&li=0& pm=5&pc= Fochtmann LJ, Gelenberg AJ. Guideline watch: practice guideline for the treatment of patients with major depressive disorder. FOCUS. 2005;3(1): Taylor D, Walsham N, Taylor SE, Wong LF. Potential interactions between prescription drugs and complementary and alternative medicines among patients in the emergency department. Pharmacotherapy. 2006;26(5): Bishop FL, Yardley L, Lewith GT. Treat or treatment: a qualitative study analyzing patients use of complementary and alternative medicine. Am J Public Health. 2008;98(9): Susan Simmons Holcomb is a nurse practitioner at Olathe Medical Services, Inc., Olathe, and a consultant at the Kansas City Kansas Community College, Kansas City, Kan. The Nurse Practitioner May