Kava hepatotoxicity: a clinical survey and critical analysis of 26 suspected cases

Kava hepatotoxicity in traditional and modern use: the presumed Pacific kava paradox hypothesis revisited

Kava, a Pacific herb consumed worldwide for medicinal, recreational and cultural purposes, has been associated with rare hepatotoxicity, and there is currently a critical need to determine this causation. The previously proposed Pacific kava paradox was based on the theory that kava hepatotoxicity was not observed following use of traditional aqueous extracts in the Pacific region, but was restricted to use of Western acetonic and ethanolic extracts. Subsequent cases analyzed by the World Health Organization and published case reports revealed that traditional aqueous extracts used in New Caledonia, Australia, the USA and Germany may also be hepatotoxic; thus, there is no longer a basis to sustain the previously proposed Pacific kava paradox. It appears that the primary cause of toxicity may reside in the time before the preparation of the various kava extracts, possibly attributed to poor quality of the raw material caused by mould hepatotoxins. Rigorous testing of kava raw material is urgently advised, in addition to Pan-Pacific kava manufacturing quality standards.

Lung Tumorigenesis Suppressing Effects of a Commercial Kava Extract and Its Selected Compounds in A/J Mice

Lung cancer is the most deadly malignancy in the US. Chemoprevention is potentially a complementary approach to smoking cessation for lung cancer control. Recently, we reported that a commercially available form of kava extract significantly inhibits 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) and benzo(a)pyrene (BaP)-induced lung tumorigenesis in A/J mice at a dose of 10 mg per gram diet. In the present study, we examined the dose-dependent lung tumor inhibitory activities of kava and investigated potential active constituent(s). Mice treated with carcinogen alone contained 12.1±5.8 lung adenomas per mouse 22 weeks after final carcinogen administration. Mice that were fed diets containing kava at dosages of 1.25, 2.5, 5, and 10 mg/g of diet had 8.4±3.5, 6.6±3.5, 4.3±2.4, and 3.8±2.3 lung adenomas per mouse, respectively. This corresponds to a reduction of 31%, 46%, 65% and 69% in tumor multiplicity, which were all statistically significant (p < 0.05). Analyses of lung adenoma tissues derived from kava-treated animals revealed that kava significantly inhibited adenoma cell proliferation while it had no detectable effect on cell death, indicating that kava primarily suppressed lung tumorigenesis in A/J mice via inhibition of cell proliferation. Flavokawains A, B, and C, three chalcone-based components from kava, demonstrated greatly reduced chemopreventive efficacies even at concentrations much higher than their natural abundance, suggesting that they alone were unlikely to be responsible for kava's chemopreventive activity. Kava at all dosages and treatment regimens did not induce detectable adverse effects, particularly with respect to liver. Specifically, kava treatment showed no effect on liver integrity indicator enzymes or liver weight, indicating that kava may be potentially safe for long-term chemopreventive application.

Suspected Greater Celandine hepatotoxicity: liver-specific causality evaluation of published case reports from Europe

BACKGROUND AND OBJECTIVES

In 21 published case reports, the use of the herb Greater Celandine (GC) (Chelidonium majus L.) has been causally related to liver injury, but a variety of confounding variables were evident that might have offset causality. This study reanalyses causality levels in these cases with a liver-specific causality evaluation method.

METHODS

All 21 cases were submitted to the liver-specific, standardized, structured, quantitative and updated scale of the Council for International Organizations of Medical Sciences. This scale considers, among other items, latency period, course of alanine aminotransferase after treatment discontinuation, risk factors, comedication and alternative causes.

RESULTS

Using this method for assessment, causality for GC was highly probable in two and probable in six cases, with lower causality grading in the remaining 13 cases. In these patients, causality for GC was possible in 10 cases and excluded in three cases. On the basis of the eight cases with highly probable and probable causality gradings, GC hepatotoxicity represents an idiosyncratic reaction of the metabolic type, whereas immunologic or obligatory hepatotoxic features are lacking. In some cases, alternative diagnoses and poor data quality were confounding variables that reduced causality levels.

CONCLUSION

Confounding variables reduced causality levels for GC in reported cases of liver injury, but there is still striking evidence for herb-induced liver injury by GC with high causality gradings. GC hepatotoxicity is caused by an idiosyncratic reaction of the metabolic form, but there is uncertainty with respect to its culprit(s).

Spontaneous reports of primarily suspected herbal hepatotoxicity by Pelargonium sidoides: was causality adequately ascertained?

Spontaneous reports of primarily assumed hepatotoxicity in connection with the use of Pelargonium sidoides (PS) have been interpreted by the Drug Commission of the German Medical Association (DCGMA) as showing some hepatotoxic potential of PS used to treat common cold and other respiratory tract infections. Causality for PS was assessed using the liver specific, structured, quantitative, and updated scale of the Council for International Organizations of Medical Sciences (CIOMS). In none of the 15 cases was there a highly probable or probable causality for PS. Analysis revealed confounding factors such as numerous final diagnoses unrelated to PS and poor data quality in virtually all cases. In only a minority of the cases were data provided to consider even common other diseases of the liver. For instance, biliary tract imaging data were available in only 3 patients; data to exclude virus infections by hepatitis A-C were provided in 4 cases and by CMV and EBV in 1 case, whereas HSV and VZV virus infections remained unconsidered. Thus, convincing evidence is lacking that PS was a potential hepatotoxin in the analyzed cases.

Which psychotropic medications induce hepatotoxicity?

OBJECTIVE

Safe prescribing practices to minimize pharmaceutically induced liver damage or worsening of preexisting conditions require knowledge about medicines with hepatotoxic potential. This paper reviews psychotropic medications and their effects on the liver.

METHODS

A MEDLINE search was performed utilizing the phrase "drug-induced liver injury" with various categories of psychiatric drugs. Only articles written in English were utilized.

RESULTS

Hepatotoxicity can be acute or chronic in nature. Medication discontinuation is necessary in acute forms, while close monitoring is required in milder forms of medication-induced chronic liver damage. Nefazodone, pemoline and/or tacrine are the highest offenders. Carbamazepine and valproate products (e.g., divalproex) can lead to this adverse event and should be avoided in patients with liver disease, persons with alcohol misuse or those consuming high doses of acetaminophen.

CONCLUSION

Knowing the risk levels associated with various medicines is important; prescribing multiple drugs with hepatotoxic effects should be avoided. One should educate patients about early warning signs of liver injury. Always provide clinical and laboratory monitoring before and during the use of hepatotoxic drugs. Clinical features and laboratory results govern medication prescribing with ongoing risk-to-benefit ratio assessment during pharmacotherapy.

Liver toxicity and carcinogenicity in F344/N rats and B6C3F1 mice exposed to Kava Kava

Kava Kava is an herbal supplement used as an alternative to antianxiety drugs. Although some reports suggest an association of Kava Kava with hepatotoxicity , it continues to be used in the United States due to lack of toxicity characterization. In these studies F344/N rats and B6C3F1 mice were administered Kava Kava extract orally by gavage in corn oil for two weeks, thirteen weeks or two years. Results from prechronic studies administered Kava Kava at 0.125 to 2g/kg body weight revealed dose-related increases in liver weights and incidences of hepatocellular hypertrophy. In the chronic studies, there were dose-related increases in the incidences of hepatocellular hypertrophy in rats and mice administered Kava Kava for up to 1g/kg body weight. This was accompanied by significant increases in incidences of centrilobular fatty change. There was no treatment- related increase in carcinogenic activity in the livers of male or female rats in the chronic studies. Male mice showed a significant dose-related increase in the incidence of hepatoblastomas. In female mice, there was a significant increase in the combined incidence of hepatocellular adenoma and carcinoma in the low and mid dose groups but not in the high dose group. These findings were accompanied by several nonneoplastic hepatic lesions.

Spontaneous reports of assumed herbal hepatotoxicity by black cohosh: is the liver-unspecific Naranjo scale precise enough to ascertain causality?

PURPOSE

Causality assessment of cases with herbal hepatotoxicity represents a major regulatory challenge and included, in the past, the application of a diagnostic algorithm consisting of causality evaluation methods with either liver-specific or liver-unspecific characteristics. To evaluate various causality assessing methods in cases with suspected herbal hepatotoxicity, two different scales were now used for reasons of comparison.

METHODS

We used the liver-specific scale of the updated Council for International Organizations of Medical Sciences (CIOMS) as well as the Naranjo scale that is not organ specific and therefore not liver specific. Both scales were applied to 22 cases of spontaneous reports with initially assumed herbal hepatotoxicity caused by black cohosh, used for menopausal symptoms.

RESULTS

The analysis shows that causality was either unlikely (n = 6) or excluded (n = 16), using the updated CIOMS scale. There were various confounding variables: pre-existing liver diseases (n = 6) including genuine autoimmune hepatitis or alcoholic or cardiac hepatopathy; hepatotoxicity induced by interferon or fluoxetine (n = 2); marginally increased serum activities of alanine aminotransferase (n = 2) or gamma-glutamyltranspeptidase (n = 2) of unassessable causality; a mixed group consisting of unassessable cases (n = 6) and cases with questionable, poorly documented hepato-biliary diseases (n = 3); and rosuvastin-induced rhabdomyolysis (n = 1). These confounding factors were not recognized by the Naranjo scale.

CONCLUSIONS

Structured hepatotoxicity-specific causality assessment methods such as the updated CIOMS scale are the preferred tools for causality assessment of assumed herbal hepatotoxicity and should replace the liver-unspecific Naranjo scale. Applying the updated CIOMS scale to cases with initially assumed hepatotoxicity by BC, causality was now found either unlikely or excluded.

The impact of complementary and alternative treatment modalities on the care of orthopaedic patients

The use of complementary and alternative medicine is widespread and popular with the lay public. Although prevalence of use varies among specific patient populations, complementary and alternative medicine, in particular herbal remedies, are widely marketed and used by orthopaedic patients. Herbal supplements can have a negative impact on the perioperative period and may interact with conventional medicines used to manage chronic conditions. Physician-patient communication often does not include the subject of alternative medicines, leading to underreporting of use. Orthopaedic surgeons should adopt methods to routinely elicit from their patients the use of complementary and alternative medicine and should monitor and counsel patients on potential side effects and drug-herb interactions. Preoperative instructions should include cessation of the use of herbal supplements.

Herbal hepatotoxicity by kava: update on pipermethystine, flavokavain B, and mould hepatotoxins as primarily assumed culprits

Herbal hepatotoxicity by the anxiolytic kava (Piper methysticum Forst. f.) emerged unexpectedly and was observed in a few patients worldwide. Liver injury occurred after the use of traditional aqueous kava extracts in the South Pacific region and of acetonic and ethanolic extracts in Western countries in rare cases, suggesting that the solvents used play no major causative role. In this review, we discuss actual pathogenetic issues of kava hepatotoxicity with special focus on developments regarding pipermethystine, flavokavain B, and mould hepatotoxins as possible culprits. There is abundant data of in vitro cytotoxicity including apoptosis by pipermethystine and flavokavain B added to the incubation media, yet evidence is lacking of in vivo hepatotoxicity in experimental animals under conditions similar to human kava use. Furthermore, in commercial Western kava extracts, pipermethystine was not detectable and flavokavain B was present as a natural compound in amounts much too low to cause experimental liver injury. There is concern, however, that due to high temperature and humidity in the South Pacific area, kava raw material might have been contaminated by mould hepatotoxins such as aflatoxins after harvest and during storage. Whether kava hepatotoxicity may be due to aflatoxicosis or other mould hepatotoxins, requires further studies.

Herbal hepatotoxicity by Greater Celandine (Chelidonium majus): causality assessment of 22 spontaneous reports

Toxic liver injury due to the herb Greater Celandine (GC) (Chelidonium majus L.) has been assumed in patients originating from various European countries and created concern. Based on regulatory and liver unspecific ad hoc causality assessments in 22 spontaneous cases of Germany, causality levels for GC were considered probable in 16 and possible in 6 cases. We now analyzed the data of these 22 cases regarding their causality levels employing the liver specific, standardized, structured and quantitative assessment method of the updated scale of CIOMS (Council for International Organizations of Medical Sciences). Causality for GC was found highly probable (n=2), probable (n=6), possible (n=10), unlikely (n=1), and excluded (n=3). Thus, causality could be upgraded in 2 cases to a highly probable causality level, but had to be down graded to excluded, unlikely, or possible causality levels in 3, 1, or 9 cases, respectively. GC hepatotoxicity shows a hepatocellular pattern of liver injury with female gender predominance. On average, age of the patients was 56.4 years, treatment 36.4 days, and latency period until first symptoms and jaundice 29.8 and 35.6 days, respectively. This analysis therefore provides further evidence for the existence of GC hepatotoxicity as a distinct form of herb induced liver injury, but due to poor data quality the causal association between GC use and liver injury is less strong than hitherto assumed. We propose replacement of the regulatory organ unspecific by a liver specific causality assessment method in cases of herb induced liver injury as well as stricter pharmacovigilance strategies towards improvements of data quality. Toxicological studies are now warranted to elucidate the mechanism(s) of human GC hepatotoxicity that represents a European issue.

Proposal for a kava quality standardization code

Rare cases of hepatotoxicity emerged with the use of kava drugs and dietary supplements prepared from rhizomes and roots of the South Pacific plant kava (Piper methysticum). Their psychoactive, anxiolytic, relaxing, and recreational ingredients are the kavalactones kavain, dihydrokavain, methysticin, dihydromethysticin, yangonin, and desmethoxyyangonin, but there is little evidence that these kavalactones or the non-kavalactones pipermethystine and flavokavain B are the culprits of the adverse hepatic reactions. It rather appears that poor quality of the kava material was responsible for the liver toxicity. Analysis of existing kava quality standardizations with focus on chemical, agricultural, manufacturing, nutritional, regulatory, and legislation backgrounds showed major shortcomings that could easily explain quality problems. We therefore suggest a uniform, internationally accepted device for kava quality standardizations that are in the interest of the consumers because of safety reasons and will meet the expectations of kava farmers, pharmaceutical manufacturers, regulators of agencies, and legislators. The initial step resides in the establishment of Pan-Pacific kava quality legislation as an important part of the proposed Kava Quality Standardization Code. In conclusion, a sophisticated approach to establish kava quality standardizations is needed for safe human use of kava as relaxing traditional beverages, the anxiolytic drugs, and recreational dietary supplements.

Kava, the anxiolytic herb: back to basics to prevent liver injury?

The use of the anxiolytic herb kava has caused toxic liver injury in Western countries and economic problems in South Pacific Islands due to tthe regulatory ban on kava. This analysis shows poor quality of kava raw material as a cause for its toxicity and suggests preventative measures by going back to the traditional use of kava for the sake of the patients and the South Pacific economy.

Kava and kava hepatotoxicity: requirements for novel experimental, ethnobotanical and clinical studies based on a review of the evidence

Kava hepatotoxicity is a well described disease entity, yet there is uncertainty as to the culprit(s). In particular, there is so far no clear evidence for a causative role of kavalactones and non-kavalactone constituents, such as pipermethystine and flavokavain B, identified from kava. Therefore, novel enzymatic, analytical, toxicological, ethnobotanical and clinical studies are now required. Studies should focus on the identification of further potential hepatotoxic constituents, considering in particular possible adulterants and impurities with special reference to ochratoxin A and aflatoxins (AFs) producing Aspergillus varieties, which should be urgently assessed and published. At present, Aspergillus and other fungus species producing hepatotoxic mycotoxins have not yet been examined thoroughly as possible contaminants of some kava raw materials. Its occurence may be facilitated by high humidity, poor methods for drying procedures and insufficient storage facilities during the time after harvest. Various experimental studies are recommended using aqueous, acetonic and ethanolic kava extracts derived from different plant parts, such as peeled rhizomes and peeled roots including their peelings, and considering both noble and non-noble kava cultivars. In addition, ethnobotanical studies associated with local expertise and surveillance are required to achieve a good quality of kava as the raw material. In clinical trials of patients with anxiety disorders seeking herbal anxiolytic treatment with kava extracts, long-term safety and efficacy should be tested using traditional aqueous extracts obtained from peeled rhizomes and peeled roots of a noble kava cultivar, such as Borogu, to evaluate the risk: benefit ratio. Concomitantly, more research should be conducted on the bioavailability of kavalactones and non-kavalactones derived from aqueous kava extracts. To be on the side of caution and to ensure lack of liver injury, kava consuming inhabitants of the kava producing or importing South Pacific islands should undergo assessment of their liver function values and serum aflatoxin levels. The primary aim is to achieve a good quality of kava raw material, without the risk of adulterants and impurities including ochratoxin A and AFs, which represent the sum of aflatoxin B1, B2, G1 and G2. Although it is known that kava may naturally be contaminated with AFs, there is at present no evidence that kava hepatotoxicity might be due to aflatoxicosis. However, appropriate studies have yet to be done and should be extended to other mould hepatotoxins, with the aim of publishing the obtained results. It is hoped that with the proposed qualifying measures, the safety of individuals consuming kava will substantially be improved.

Toxicokinetics of kava

Kava is traditionally consumed by South Pacific islanders as a drink and became popular in Western society as a supplement for anxiety and insomnia. Kava extracts are generally well tolerated, but reports of hepatotoxicity necessitated an international reappraisal of its safety. Hepatotoxicity can occur as an acute, severe form or a chronic, mild form. Inflammation appears to be involved in both forms and may result from activation of liver macrophages (Kupffer cells), either directly or via kava metabolites. Pharmacogenomics may influence the severity of this inflammatory response.

Kava hepatotoxicity: comparative study of two structured quantitative methods for causality assessment

BACKGROUND AND OBJECTIVE

Ingestion of the medicinal herb kava has been associated with hepatotoxicity. We aimed to compare two different quantitative methods of causality assessment of patients with assumed hepatotoxicity by the herb.

METHODS

We assessed causality in 26 patients from Germany and Switzerland, using two structured quantitative analytical methods: the system of Maria and Victorino (MV) and that of the Council for International Organizations of Medical Sciences (CIOMS). In all 26 patients, regulatory ad hoc evaluation had suggested a causal relationship between liver disease and kava use.

RESULTS AND DISCUSSION

Assessment with the MV scale resulted in no or low graded causality for kava in the 26 patients with liver disease. Causality was probable (n=1), possible (n=2), unlikely (n=7), and excluded (n=16). Causality for kava was more evident with the CIOMS scale: highly probable (n=1), probable (n=2), possible (n=6), unlikely (n=2) and excluded (n=15). However, the results of both quantitative causality assessments are not supportive for most of the regulatory ad hoc causality assessments of the 26 patients.

CONCLUSION

Grades of causality for suspected hepatotoxicity by kava were much lower when evaluated by structured quantitative causality assessment scales than by regulatory ad hoc judgements. The quantitative CIOMS scale is the preferable tool for causality assessment of spontaneous reports of hepatotoxcity involving kava.

Kava hepatotoxicity solution: A six-point plan for new kava standardization

Kava-induced liver injury has been demonstrated in a few patients worldwide and appears to be caused by inappropriate quality of the kava raw material. When cases of liver disease in connection with the use of kava emerged, this was an unexpected and challenging event considering the long tradition of safe kava use. In order to prevent kava hepatotoxicity in future, a set of quality specifications as standard is essential for the preparation not only of kava drugs and kava dietary supplements in the Western world but also for traditional kava drinks in the South Pacific Islands. For all these purposes a uniform approach is required, using water based extracts from the peeled rhizomes and roots of a noble cultivar such as Borogu with at least 5 years of age at the time of harvest. Cultivated in Vanuatu for centuries, noble varieties (as defined in the Vanuatu Kava Act of December 2002) are well tolerated traditional cultivars with a good safety record. At present, Vanuatu kava legislation is inadequately enforced to meet quality issues for kava, and further efforts are required in Vanuatu, in addition to similar legislation in other kava producing South Pacific Islands. Future regulatory and commercial strategies should focus not only on the standardization of kava drugs, kava dietary supplements, and traditional kava extracts, but also on thorough surveillance during the manufacturing process to improve kava quality for safe human use. The efficacy of kava extracts to treat patients with anxiety disorders is well supported, but further clinical trials with aqueous kava extracts are necessary. We thereby propose a six-point kava solution plan: (1) use of a noble kava cultivar such as Borogu, at least 5 years old at time of harvest, (2) use of peeled and dried rhizomes and roots, (3) aqueous extraction, (4) dosage recommendation of ≤250mg kavalactones per day (for medicinal use), (5) systematic rigorous future research, and (6) a Pan Pacific quality control system enforced by strict policing. In conclusion, at different levels of responsibility, new mandatory approaches are now required to implement quality specification for international acceptance of kava as a safe and effective anxiolytic herb.

An approach to the psychopharmacologic care of patients: antidepressants, antipsychotics, anxiolytics, mood stabilizers, and natural remedies

The number of safe and effective medication treatments for psychiatric illness has expanded substantially over the past 10 to 15 years. Knowing when and how to prescribe psychotropics--and knowing which medication to prescribe--can be challenging, but with knowledge of some basic principles, this task can be performed adeptly by physicians of all specialties. In this article, the authors discuss basic principles of psychopharmacology and outline an approach to using several commonly prescribed classes of medications.

Regulatory causality evaluation methods applied in kava hepatotoxicity: are they appropriate?

Since 1998 liver injury has been assumed in some patients after the use of kava (Piper methysticum G. Forster) as an anxyolytic herbal extract, but the regulatory causality evaluation of these cases was a matter of international and scientific debate. This review critically analyzes the regulatory issues of causality assessments of patients with primarily suspected kava hepatotoxicity and suggests recommendations for minimizing regulatory risks when assessing causality in these and other related cases. The various regulatory causality approaches were based on liver unspecific assessments such as ad hoc evaluations, the WHO scale using the definitions of the WHO Collaborating Centre for International Drug Monitoring, and the Naranjo scale. Due to their liver unspecificity, however, these causality approaches are not suitable for assessing cases of primarily assumed liver related adverse reactions by drugs and herbs including kava. Major problems emerged trough the combination of regulatory inappropriate causality assessment methods with the poor data quality as presented by the regulatory agency when reassessment was done and the resulting data were heavily criticized worldwide within the scientific community. Conversely, causality of cases with primarily assumed kava hepatotoxicity is best assessed by structured, quantitative and liver specific causality algorithms such as the scale of the CIOMS (Council for International Organizations of Medical Sciences) or the main-test as its update. Future strategies should therefore focus on the implementation of structured, quantitative and liver specific causality assessment methods as regulatory standards to improve regulatory causality assessments for liver injury by drugs and herbs including kava.

Black cohosh and suspected hepatotoxicity: inconsistencies, confounding variables, and prospective use of a diagnostic causality algorithm. A critical review

OBJECTIVE

The data of 69 cases of initially suspected black cohosh (BC)-induced liver disease were reviewed and analyzed to clarify whether BC hepatotoxicity really exists as a disease entity in these cases comparable to toxic liver disease being caused by various drugs and dietary supplements.

METHODS

The cases comprised 11 published case reports and 58 spontaneous reports to national regulatory agencies. The analysis includes assessment of causality for BC, data quality of the presented cases, and their inconsistencies and confounding variables.

RESULTS

The assessed data raise serious doubts on the initial claims of causality for BC in these cases and provide clear evidence of their poor quality, especially when spontaneous reports are considered. There are major inconsistencies for the same patient regarding reported data. Moreover, the analysis of all cases disclosed confounding variables. These include poor case data quality, uncertainty of BC product, quality, and identification, undisclosed indication, insufficient adverse event definition, lack of temporal association and dechallenge, missing or inadequate evaluation of alcohol use, comedication, comorbidity, reexposure test, and alternative diagnoses.

CONCLUSIONS

The presented data do not support the concept of hepatotoxicity in a primarily suspected causal relationship to the use of BC and failure to provide a signal of safety concern, but further efforts have to be undertaken to dismiss or to substantiate the existence of BC hepatotoxicity as a special disease entity. The future strategy should be focused on prospective causality evaluations in patients diagnosed with suspected BC hepatotoxicity, using a structured, quantitative, and hepatotoxicity-specific causality assessment method.

Kava hepatotoxicity: regulatory data selection and causality assessment

BACKGROUND

Kava hepatotoxicity in 20 patients from Germany has been debated worldwide following a regulatory ad hoc causality assessment and ban of kava, an anxiolytic herbal remedy obtained from the rhizome of Piper methysticum Forster.

AIMS

We assessed causality with a quantitative structured causality analysis in all 20 cases of patients with liver disease, presented by the German regulatory agency that assumed a causal relationship with the use of kava extracts.

METHODS

The quantitative scale of CIOMS (Council for International Organizations of Medical Sciences) in its updated form was employed for causality assessment and quality evaluation of the regulatory data presentation.

RESULTS

The regulatory information is scattered and selective, and items essential for causality assessment, such as exclusion of kava independent causes, were not, or only marginally, considered by the regulator. Quantitative causality assessment for kava was possible (n=2), unlikely (n=12), or excluded (n=6), showing no concordance with the regulatory ad hoc causality evaluation.

CONCLUSION

The regulatory data regarding kava hepatotoxicity is selective and of low quality, not supportive of the regulatory proposed causality; but instead, is an explanation of the overall causality discussions of kava hepatotoxicity. We are proposing that the regulatory agency reports data in full length and reevaluates causality.

Black cohosh hepatotoxicity: quantitative causality evaluation in nine suspected cases

OBJECTIVE

Black cohosh (BC), synonym for Actaea racemosa and Cimicifuga racemosa, is a herbal remedy for the treatment of menopausal symptoms. Recently, worldwide discussions have emerged as to whether its use maybe associated with the risk of rare hepatotoxicity in a few susceptible women.

METHODS

We have evaluated the causal relationship in nine cases with suspected hepatotoxicity by the use of BC. The updated Council for International Organizations of Medical Sciences scale was used to quantitatively assess the causality for BC.

RESULTS

In eight of nine patients with liver disease, causality for BC +/- comedication was excluded (n = 4) or unlikely (n = 4). The failure to ascribe causality in these cases was mainly due to alternative diagnosis, missing temporal association and dechallenge, and presentation of low quality data. In only one case, causality was possible for a BC preparation of an unknown brand taken for 2 months with an unknown daily dose. Confounding factors in this case include symptomatic cholelithiasis and fatty liver. Comedication with synthetic drugs and herbal or other dietary supplements was reported in five of nine patients.

CONCLUSIONS

In nine cases of patients with liver disease, causality for BC +/- comedication was possible (n = 1), unlikely (n = 4), or excluded (n = 4). Due to this lack of significant circumstantial evidence, the present study shows little, if any, hepatotoxic risks by the use of BC in the analyzed cases.

Kava and St. John's Wort: current evidence for use in mood and anxiety disorders

BACKGROUND

Mood and anxiety disorders pose significant health burdens on the community. Kava and St. John's wort (SJW) are the most commonly used herbal medicines in the treatment of anxiety and depressive disorders, respectively.

OBJECTIVES

The objective of this study was to conduct a comprehensive review of kava and SJW, to review any evidence of efficacy, mode of action, pharmacokinetics, safety and use in major depressive disorder, bipolar disorder, seasonal affective disorder (SAD), generalized anxiety disorder, social phobia (SP), panic disorder (PD), obsessive-compulsive disorder (OCD), and post-traumatic stress disorder (PTSD).

METHODS

A systematic review was conducted using the electronic databases MEDLINE, CINAHL, and The Cochrane Library during late 2008. The search criteria involved mood and anxiety disorder search terms in combination with kava, Piper methysticum, kavalactones, St. John's wort, Hypericum perforatum, hypericin, and hyperforin. Additional search criteria for safety, pharmacodynamics, and pharmacokinetics were employed. A subsequent forward search was conducted of the papers using Web of Science cited reference search.

RESULTS

Current evidence supports the use of SJW in treating mild-moderate depression, and for kava in treatment of generalized anxiety. In respect to the other disorders, only weak preliminary evidence exists for use of SJW in SAD. Currently there is no published human trial on use of kava in affective disorders, or in OCD, PTSD, PD, or SP. These disorders constitute potential applications that warrant exploration.

CONCLUSIONS

Current evidence for herbal medicines in the treatment of depression and anxiety only supports the use of Hypericum perforatum for depression, and Piper methysticum for generalized anxiety.

Drug-induced liver injury: what was new in 2008?

BACKGROUND

Given the number of publications appearing annually regarding drug-induced liver injury (DILI), there remains a need to concisely summarize each year's new crop of case series and reports as well as the advances in mechanisms of liver injury and in the field of pharmacogenomics relating to DILI.

OBJECTIVE

To present an up-to-date review of the past year's most important clinical studies and reports of DILI, placing them into context of previous publications.

METHODS

A Medline search was conducted of all manuscripts appearing in the fields "hepatotoxicity" and "drug-induced liver injury" during the calendar year 2008. The most clinically relevant English language case reports and studies exploring mechanisms and risk factors for DILI were then chosen for review, and supplemented with older literature where appropriate.

CONCLUSIONS

As in past years, 2008 was replete with publications dealing with virtually all facets of DILI, including updated incidence and prevalence data, as well as the latest information regarding mechanisms of liver injury. Data from the first 300 patients in the National Institute of Health-sponsored DILI Network registry of > 100 non-acetaminophen causes were presented. Antimicrobials and CNS drugs were responsible for > 60% of cases, with herbals and dietary supplements being increasingly reported. Identification of genetic predispositions to DILI is coming of age with the FDA calling for the testing of human leukocyte antigen B(*)5701 before the use of abacavir to reduce the risk of hypersensitivity reactions. Several groups emphasized the pitfalls in utilizing Roussel Uclaf Causality Assessment Method and other causality assessment methodologies, and an updated review appeared on the use of potentially hepatotoxic medications in patients with underlying liver disease.

Identification of methysticin as a potent and non-toxic NF-kappaB inhibitor from kava, potentially responsible for kava's chemopreventive activity

Nuclear factor-kappaB (NF-kappaB) is a transcription factor that plays an essential role in cancer development. The results of our recent chemopreventive study demonstrate that kava, a beverage in the South Pacific Islands, suppresses NF-kappaB activation in lung adenoma tissues, potentially a mechanism responsible for kava's chemopreventive activity. Methysticin is identified as a potent NF-kappaB inhibitor in kava with minimum toxicity. Other kava constituents, including four kavalactones of similar structures to methysticin, demonstrate minimum activities in inhibiting NF-kappaB.

Suspected black cohosh hepatotoxicity--challenges and pitfalls of causality assessment

OBJECTIVES

Black cohosh (BC) is a herbal drug or herbal dietary supplement used for treatment of menopausal symptoms. Recently, however, reports have appeared about the occurrence of rare toxic liver disease in an assumed relationship with the use of BC.

METHODS

We have analyzed and reviewed the data of all 69 reported cases with suspected BC hepatotoxicity. Causality for BC was assessed utilizing the scale of the original structured quantitative Council for International Organizations of Medical Sciences (CIOMS), or the main-test as its updated form.

RESULTS

With the hepatotoxicity specific causality assessment methods, there was an excluded, unlikely, unrelated or unassessable causality for BC in 68 of 69 cases with liver disease. One patient had a possible causality for BC and a symptomatic cholelithiasis with confounding variables of fatty liver of unknown etiology; unknown BC brand including possible herbal mixture; unknown daily BC dosage; and an unassessable duration of BC usage. In general, the cases of the 69 patients were poorly documented. Confounding variables were: failure to identify the BC product; use of herbal mixtures with multiple ingredients in addition to BC; co-medication with synthetic drugs and dietary supplements including herbal ones; missing temporal association between BC use and development of liver disease; not specified modalities of BC treatment; failure of dechallenge after BC discontinuation; pre-existing liver diseases; insufficiently excluded other liver diseases; presence of alternative liver diseases.

CONCLUSIONS

The analysis of 69 cases shows little, if any, supportive evidence for a significant hepatotoxic risk of BC.

Severe hepatotoxicity by Indian Ayurvedic herbal products: a structured causality assessment

The case of a 64 year old female patient is presented who has treated herself for 9 months with various Indian Ayurvedic herbal products for her vitiligo and experienced a causally related severe hepatotoxicity (ALT, 601 U/L; AST, 663 U/L; Bilirubin, 5.0 mg/dL). After discontinuation, a rapid improvement was observed. Causality assessment with the updated CIOMS (Council for International Organizations of Medical Sciences) scale showed a probable causality (+8 points) for Bakuchi tablets containing extracts from Psoralea corylifolia leaves with psoralens as ingredients, as the primary candidate causing the hepatotoxic reaction. The degree of probability was lower with +6 points for other used herbs: Khadin tablets containing extracts from Acacia catechu leaves; Brahmi tablets containing Eclipta alba or Bacopa monnieri; and Usheer tea prepared from Vetivexia zizaniodis. The case is the first report of Indian Ayurvedic herbal products being potentially hepatotoxic in analogy to some other herbs.

Kava hepatotoxicity: comparison of aqueous, ethanolic, acetonic kava extracts and kava-herbs mixtures

ETHNOPHARMACOLOGICAL RELEVANCE

Ethanolic and acetonic kava extracts have previously been causally related to rare hepatotoxicity observed in patients from Germany and Switzerland, but causality assessment was not performed in cases of patients having taken the traditional aqueous kava extracts of South Pacific islands or kava-herbs mixtures.

AIM OF THE STUDY

To study the possible hepatotoxicity of aqueous kava extracts of the South Pacific Islands.

MATERIALS AND METHODS

Causality of hepatotoxicity by aqueous kava extracts and kava-herbs mixtures was assessed, using the updated score of the quantitative CIOMS (Council for the International Organizations of Medical Sciences).

RESULTS

Causality was established in five patients from New Caledonia, Australia, the United States and Germany for aqueous kava extracts and kava-herbs mixtures. A comparison with 9 patients from Germany and Switzerland with established causality of hepatotoxicity by ethanolic and acetonic kava extracts reveals that the clinical picture in all 14 patients is similar, independently whether aqueous, ethanolic and acetonic kava extracts or kava-herbs mixtures were used.

CONCLUSIONS

Kava hepatotoxicity occurs also with traditional aqueous kava extracts of the South Pacific islands and thereby independently from ethanol or acetone as chemical solvents, suggesting that the toxicity is linked to the kava plant itself with a possibly low quality of the used kava cultivar or kava plant part rather than to chemical solvents.