Saccade and cognitive impairment associated with kava intoxication

Health policy versus kava (Piper methysticum): Anxiolytic efficacy may be instrumental in restoring the reputation of a major South Pacific crop

ETHNOPHARMACOLOGICAL RELEVANCE

Kava (Piper methysticum G. Forst. f.) is by far the most important plant used in the islands of Melanesia, Polynesia and Micronesia for its relaxing effects. Kava drinking is a pillar of South Pacific societies and is also the foundation of their economies. Preparations of kava extract as herbal medicinal drugs were banned in Germany in 2002 and again in 2019, with dramatic consequences for the South Pacific economies. In 2002, the major regulatory argument for the ban of kava was safety issues. In 2019, the assessment report of the European Medicines Agency's Herbal Medicinal Product Committee (HMPC) justified a negative benefit-to-risk ratio by a supposed lack of efficacy of ethanolic extracts for an indication of which kava extract preparations never had an approval. In this HMPC report the efficacy in the approved indications 'nervous anxiety, tension and restlessness' was attributed to the extract branded as 'WS 1490', which was assumed to have been prepared with acetone as an extraction solvent. In addition to this change of indication and the attribution of efficacy to acetone kava extract alone, the German health authorities and the HMPC still refuse to discuss quality issues as a likely factor impacting drug safety. The first case reports of liver toxicity were observed with an acetone extract in a timely relationship with the introduction of 'two-day kava' instead of 'noble kava' as used in ethanolic kava extracts.

AIM OF THE STUDY

The correlation between clinical benefits and the type of extract preparation was examined.

METHODS

In order to identify the types of kava material and extracts used in clinical trials, the respective publications were compared with regulatory databases and protocols of a German regulatory advisory board.

RESULTS AND CONCLUSIONS

The comparison reveals inconsistencies in the regulatory decisions. In all studies with WS 1490, the evidence points to the use of an ethanolic extract. The efficacy of kava extract for the approved indication was clearly demonstrated. The HMPC report and the recent renewed German regulatory ban of kava therefore require major revision, which should include the impact of the use of "two-day kava" on drug safety. Such a revision could contribute to restoring the reputation of "noble kava" on the international markets.

Pharmacology of Herbal Sexual Enhancers: A Review of Psychiatric and Neurological Adverse Effects

Sexual enhancers increase sexual potency, sexual pleasure, or libido. Substances increasing libido alter the concentrations of specific neurotransmitters or sex hormones in the central nervous system. Interestingly, the same pathways are involved in the mechanisms underlying many psychiatric and neurological disorders, and adverse reactions associated with the use of aphrodisiacs are strongly expected. However, sexual enhancers of plant origin have gained popularity over recent years, as natural substances are often regarded as a safer alternative to modern medications and are easily acquired without prescription. We reviewed the psychiatric and neurological adverse effects associated with the consumption of herbal aphrodisiacs Areca catechu L., Argemone Mexicana L., Citrus aurantium L., Eurycoma longifolia Jack., Lepidium meyenii Walp., Mitragyna speciosa Korth., Panax ginseng C. A. Mey, Panax quinquefolius L., Pausinystalia johimbe (K. Schum.) Pierre ex Beille, Piper methysticum G. Forst., Ptychopetalum olacoides Benth., Sceletium tortuosum (L.) N. E. Brown, Turnera diffusa Willd. ex. Schult., Voacanga africana Stapf ex Scott-Elliot, and Withania somnifera (L.) Dunal. A literature search was conducted on the PubMed, Scopus, and Web of Science databases with the aim of identifying all the relevant articles published on the issue up to June 2020. Most of the selected sexual enhancers appeared to be safe at therapeutic doses, although mild to severe adverse effects may occur in cases of overdosing or self-medication with unstandardized products. Drug interactions are more concerning, considering that herbal aphrodisiacs are likely used together with other plant extracts and/or pharmaceuticals. However, few data are available on the side effects of several plants included in this review, and more clinical studies with controlled administrations should be conducted to address this issue.

3D Imaging and metabolomic profiling reveal higher neuroactive kavalactone contents in lateral roots and crown root peels of Piper methysticum (kava)

BACKGROUND

Kava is an important neuroactive medicinal plant. While kava has a large global consumer footprint for its clinical and recreational use, factors related to its use lack standardization and the tissue-specific metabolite profile of its neuroactive constituents is not well understood.

RESULTS

Here we characterized the metabolomic profile and spatio-temporal characteristics of tissues from the roots and stems using cross-platform metabolomics and a 3D imaging approach. Gas chromatography-mass spectrometry and liquid chromatography-mass spectrometry revealed the highest content of kavalactones in crown root peels and lateral roots. Infrared matrix-assisted laser desorption electrospray ionization (IR-MALDESI) imaging revealed a unique tissue-specific presence of each target kavalactone. X-ray micro-computed tomography analysis demonstrated that lateral roots have morphological characteristics suitable for synthesis of the highest content of kavalactones.

CONCLUSIONS

These results provide mechanistic insights into the social and clinical practice of the use of only peeled roots by linking specific tissue characteristics to concentrations of neuroactive compounds.

DARK Classics in Chemical Neuroscience: Kava

Kava (kava kava, Piper methysticum) is a common drug-containing plant in the Pacific islands. Kavalactones, its psychoactive compounds, exert potent central nervous system (CNS) action clinically and in animal models. However, the exact pharmacological profiles and mechanisms of action of kava on the brain and behavior remain poorly understood. Here, we discuss clinical and experimental data on kava psychopharmacology and summarize chemistry and synthesis of kavalactones. We also review its societal impact, drug use and abuse potential, and future perspectives on translational kava research.

Amoebic Liver Abscesses in Fiji: Epidemiology, Clinical Presentation and Comparison of Percutaneous Aspiration and Percutaneous Catheter Drainage

BACKGROUND

Amoebic liver abscess (ALA) is a common clinical problem in tropical countries related to poor sanitation. The epidemiology and clinical presentation of ALA in Fiji has not been previously described. It is unclear whether percutaneous aspiration (PA) or percutaneous catheter drainage (PCD) has better outcomes.

PURPOSE

The aims were to describe the epidemiology and clinical presentation of ALA in Fiji and to compare the outcomes of PA and PCD for treatment of ALA.

METHODS

A retrospective case note review of patients treated with either PA or PCD between 2010 and 2015 was performed. Indications for intervention were ALA > 5 cm, ALA in the left lateral lobe, risk of imminent rupture and failure to respond to medical treatment.

RESULTS

There were 262 patients, 90% were male, 92.9% I-Taukei ethnicity and 86.2% regular recreational kava drinkers. Most presented with upper abdominal pain and fevers. The majority (90.3%) had a single abscess with 87.8% being in the right lobe. 174 (66.4%) had LA and 88 (33.6%) had PCD. There was an unintended selection bias for PA in abscess with a volume of <1 litre. PA was associated with a more rapid resolution of fever and shorter hospital stay, more rapid resolution of the cavity and no morbidity. PCD had five complications, one bleed and four bile leaks. There was no mortality in either group.

CONCLUSIONS

ALA in Fiji occurs in I-Taukei males who drink kava. PA appears to offer equivalent if not better outcomes for treatment of ALA.

Cases of Kava Impairment in Iowa Drivers

Kava is an Oceanic plant in which the root is consumed as a beverage and is becoming increasingly popular. The effects of kava consumption may include sedation, euphoria, and impairment of motor coordination. This article demonstrates kava impairment through four cases of self-reported kava use supported with Drug Recognition Expert (DRE) evaluations of each subject. Subject's urines screened negative for common drugs of abuse by immunoassay analysis. Urine from cases 3 and 4 were analyzed by liquid chromatography-tandem mass spectrometry, and gas chromatography-mass spectrometry, which yielded the presence of kavalactones. Subjects exhibited poor driving behavior and signs of intoxication. Indicators of impairment from multiple drug categories, central nervous system (CNS) depressants, CNS stimulants, and cannabis were observed, which may be consistent with the presence of multiple kavalactones and their diverse array of mechanisms of action. The consumption of kava can hinder one's ability to operate a vehicle safely.

When good times go bad: managing 'legal high' complications in the emergency department

Patients can use numerous drugs that exist outside of existing regulatory statutes in order to get "legal highs." Legal psychoactive substances represent a challenge to the emergency medicine physician due to the sheer number of available agents, their multiple toxidromes and presentations, their escaping traditional methods of analysis, and the reluctance of patients to divulge their use of these agents. This paper endeavors to cover a wide variety of "legal highs," or uncontrolled psychoactive substances that may have abuse potential and may result in serious toxicity. These agents include not only some novel psychoactive substances aka "designer drugs," but also a wide variety of over-the-counter medications, herbal supplements, and even a household culinary spice. The care of patients in the emergency department who have used "legal high" substances is challenging. Patients may misunderstand the substance they have been exposed to, there are rarely any readily available laboratory confirmatory tests for these substances, and the exact substances being abused may change on a near-daily basis. This review will attempt to group legal agents into expected toxidromes and discuss associated common clinical manifestations and management. A focus on aggressive symptom-based supportive care as well as management of end-organ dysfunction is the mainstay of treatment for these patients in the emergency department.

Driving following Kava Use and Road Traffic Injuries: A Population-Based Case-Control Study in Fiji (TRIP 14)

Objective

To investigate the association between kava use and the risk of four-wheeled motor vehicle crashes in Fiji. Kava is a traditional beverage commonly consumed in many Pacific Island Countries. Herbal anxiolytics containing smaller doses of kava are more widely available.

Methods

Data for this population-based case-control study were collected from drivers of ‘case’ vehicles involved in serious injury-involved crashes (where at least one road user was killed or admitted to hospital for 12 hours or more) and ‘control’ vehicles representative of ‘driving time’ in the study base. Structured interviewer administered questionnaires collected self-reported participant data on demographic characteristics and a range of risk factors including kava use and potential confounders. Unconditional logistic regression models estimated odds ratios relating to the association between kava use and injury-involved crash risk.

Findings

Overall, 23% and 4% of drivers of case and control vehicles, respectively, reported consuming kava in the 12 hours prior to the crash or road survey. After controlling for assessed confounders, driving following kava use was associated with a four-fold increase in the odds of crash involvement (Odds ratio: 4.70; 95% CI: 1.90–11.63). The related population attributable risk was 18.37% (95% CI: 13.77–22.72). Acknowledging limited statistical power, we did not find a significant interaction in this association with concurrent alcohol use.

Conclusion

In this study conducted in a setting where recreational kava consumption is common, driving following the use of kava was associated with a significant excess of serious-injury involved road crashes. The precautionary principle would suggest road safety strategies should explicitly recommend avoiding driving following kava use, particularly in communities where recreational use is common.

Is driving under the influence of kava associated with motor vehicle crashes? A systematic review of the epidemiological literature

OBJECTIVE

Kava is marketed as a herbal anxiolytic in several countries and is consumed recreationally in high doses in many indigenous Pacific and Australian Aboriginal communities. We reviewed the published literature examining the association (if any) between kava use and motor vehicle crashes (MVCs), MVC-related injuries or driving performance.

METHODS

Search of MEDLINE, EMBASE, PsycINFO, CINAHL, Scopus, AMED, Australian Medical Index, Australian Transport Index and trials registries and injury journals up to August 2014.

RESULTS

No studies quantifying the effects of kava on MVCs or related injury were located. Four experimental studies using computer-based driving simulation examined the effects of pharmacological doses of kavalactones on cognitive and visuomotor performance. While no statistically significant adverse changes attributable to kava were found, there was weak evidence of slowed reaction time. One study found the visuo-motor performance on driving simulation to be significantly impaired when kava was consumed with alcohol.

CONCLUSIONS

With equivocal evidence limited to experimental studies using simulated driving settings, the contribution of kava to MVCs is unknown.

IMPLICATIONS

The gap in knowledge regarding the potential risk of injuries associated with therapeutic and recreational use of kava requires priority attention.

Kavalactones and the endocannabinoid system: the plant-derived yangonin is a novel CB₁ receptor ligand

To investigate the possible interactions between kavalactone-based molecules and proteins of the endocannabinoid system and provide novel and synthetically accessible structural scaffolds for the design of cannabinoid receptor ligands sharing pharmacological properties with kavapyrones, a preliminary SAR analysis was performed on five commercially available natural kavalactones and nine kavalactone-analogues properly synthesized. These compounds were investigated for assessing their cannabinoid receptor binding affinity and capability of inhibiting the activity of the two major metabolic enzymes of the endocannabinoid system, fatty acid amide hydrolase (FAAH) and monoacylglycerol lipase (MAGL). Among the molecules tested, only yangonin exhibited affinity for the human recombinant CB₁ receptor with a K(i)=0.72 μM and selectivity vs. the CB₂ receptor (K(i)>10 μM). None of the compounds exhibited strong inhibitory effects on the two enzymes analyzed. The CB₁ receptor affinity of yangonin suggests that the endocannabinoid system might contribute to the complex human psychopharmacology of the traditional kava drink and the anxiolytic preparations obtained from the kava plant.

The health and social effects of drinking water-based infusions of kava: a review of the evidence

ISSUES

To review the evidence on the health and social effects of drinking kava; a water-based infusion of the roots of the kava plant.

APPROACH

Included all empirical studies of the effects of kava published 1987-2008 reporting health and social outcomes. Evidence appraised on study design (level of evidence) and standard epidemiological criteria for causality.

KEY FINDINGS

Causality indicated: scaly skin rash, weight loss, raised Gamma Glutamyl Transpeptidase liver enzyme levels, nausea, loss of appetite or indigestion; Association indicated but causality unclear: red sore eyes, impotence or loss of sexual drive, self-reported poor health, raised cholesterol, and loss of time and money, low motivation and 'slow/lazy' days following use, reduced alcohol consumption and related violence; Association hypothesised: fits or seizures, Melioidosis, Ischaemic Heart Disease, protective effects for cancer; No association indicated: cognitive performance; No association suggested: cognitive impairment, liver toxicity or permanent liver damage, other pneumonia; No association hypothesised: hallucinations.

IMPLICATIONS

The health and social implications of chronic kava drinking can be significant for individuals and communities, although most effects of even heavy consumption appear to be reversible when consumption is stopped.

CONCLUSION

An Australia-wide ban on commercial importation of kava has been in place since mid-2007, but there is no published literature to date on the impact of the ban.

Assessment of cognitive function before and after surgery for posterior cranial fossa lesions using computerized and conventional tests

Cognitive function has not been well studied after neurosurgery for posterior fossa lesions despite its potential importance in determining surgical indications and approaches. The present study evaluated changes in cognitive functions after posterior fossa surgery to detect any differences between the middle cranial fossa and lateral suboccipital approaches in 50 patients with posterior fossa lesions such as tumors and vascular diseases. Twenty-five patients underwent surgery via the middle fossa and 25 via the lateral suboccipital approaches. Computerized test battery (CogState) and conventional neuropsychological tests (serial seven-word learning test and mini-mental state examination) were examined before, 1 month after, and 3 months after surgery. All scores of the neuropsychological tests remained within normal limits after surgery. However, the scores of one computerized test battery and serial seven-word learning tests decreased significantly 1 month after surgery and recovered within 3 months, indicating temporary deterioration of short-term memory in the middle fossa group. The computerized tests detected significantly larger numbers of patients with worsened results than the conventional tests. The middle fossa approach and operation time showed correlations with the postoperative neuropsychological declines. The computerized tests could be performed easily and were beneficial for detecting subtle changes of the cognitive function after surgery. Cognitive function, especially short-term memory, may decline temporarily with the middle fossa approach and long operation time.

Neurocognitive effects of kava (Piper methysticum): a systematic review

RATIONALE

Kava (Piper methysticum) elicits dose-dependent psychotropic effects and thus may potentially deleteriously affect cognitive performance. Clinical trials have assessed the effects of kava on cognition, however, to our knowledge no systematic review has been conducted in this area.

OBJECTIVE

To systematically review the effects of kava on cognition, providing an analysis of the individual study's methodological quality, results and effect sizes.

METHODS

A systematic review was conducted of publications up to June 15th 2010, using the electronic databases MEDLINE, PsychINFO, CINAHL, Web of Science and The Cochrane Library. The search criteria involved kava and cognition related terms, e.g. memory and attention.

RESULTS

Ten human clinical trials met inclusion criteria (acute n = 7, chronic n = 3). One acute study found that kava significantly improved visual attention and working memory processes while another found that kava increased body sway. One chronic study found that kava significantly impaired visual attention during high-cognitive demand. Potential enhanced cognition may be attributed to the ability of kava to inhibit re-uptake of noradrenaline in the pre-frontal cortex, while increased body sway may be due to GABA pathway modulation.

CONCLUSIONS

The majority of evidence suggests that kava has no replicated significant negative effects on cognition.

Kava: a comprehensive review of efficacy, safety, and psychopharmacology

OVERVIEW

Kava (Piper methysticum) is a South Pacific psychotropic plant medicine that has anxiolytic activity. This effect is achieved from modulation of GABA activity via alteration of lipid membrane structure and sodium channel function, monoamine oxidase B inhibition, and noradrenaline and dopamine re-uptake inhibition. Kava is available over the counter in jurisdictions such as the USA, Australia and New Zealand. Due to this, a review of efficacy, safety and clinical recommendations is advised.

OBJECTIVE

To conduct a comprehensive review of kava, in respect to efficacy, psychopharmacology, and safety, and to provide clinical recommendations for use in psychiatry to treat generalized anxiety disorder (GAD).

METHODS

A review was conducted using the electronic databases MEDLINE, CINAHL, PsycINFO and the Cochrane Library during mid 2010 of search terms relating to kava and GAD. A subsequent forward search was conducted of key papers using Web of Science cited reference search.

RESULTS

The current weight of evidence supports the use of kava in treatment of anxiety with a significant result occurring in four out of six studies reviewed (mean Cohen's d = 1.1). Safety issues should however be considered. Use of traditional water soluble extracts of the rhizome (root) of appropriate kava cultivars is advised, in addition to avoidance of use with alcohol and caution with other psychotropic medications. Avoidance of high doses if driving or operating heavy machinery should be mandatory. For regular users routine liver function tests are advised.

CONCLUSIONS

While current evidence supports kava for generalized anxiety, more studies are required to assess comparative efficacy and safety (on the liver, cognition, driving, and sexual effects) versus established pharmaceutical comparators.

Psychological and cognitive assessment of Indigenous Australians

OBJECTIVE

The aim of the present review was to evaluate the psychological and cognitive assessments that have been considered suitable for Indigenous Australians. This will provide a basis from which future developments can occur, leading to improved mental health services for Indigenous Australians.

METHOD

Literature searches of key health science databases were conducted using the following search terms in various combinations: Indigenous, Aboriginal, cognitive, assessment, mental health, social emotional well-being, psychological, Australian. Psychological, mental health or social and emotional well-being assessments as well as cognitive assessments that have been utilized and found suitable in Indigenous Australian populations were reviewed.

RESULTS

A limited number of assessments were found and discussed and these varied in their applications.

CONCLUSIONS

Further research and development is necessary to establish a national approach to assessing or screening mental health and cognitive function among Indigenous Australians. This is an important and necessary step to improve mental health and related services for Indigenous Australians.

Permeability studies of Kavalactones using a Caco-2 cell monolayer model

OBJECTIVE

To examine the bioavailability of kavalactones in vitro and the possible differences in their bioavailability because of variations in either chemical structure or the method of extraction used.

RESEARCH DESIGN AND METHODS

Caco-2 cell monolayers were used to determine the potential bioavailability of kavalactones. Kavalactones were added to the apical layer and basolateral samples were taken over 150 min to examine the concentration diffusing across the cell monolayer. Kavalactone concentrations in these samples were determined by high pressure liquid chromatography.

RESULTS

Kavalactones were found to be potentially bioavailable as they all readily crossed the Caco-2 monolayers with apparent permeabilities (P(app)) increasing from 42 x 10(-6) cm/s and most exhibiting more than 70% crossing within 90 min. Not all differences in their bioavailability can be related to kavalactone structural differences as it appears that bioavailability may also be affected by co-extracted compounds. For example, the P(app) for kawain from ethanol extracts was higher than the values obtained for the same compound from water extracts or for the kavalactone alone.

CONCLUSIONS

While the extraction method used (ethanol or water) influences the total (but not the relative) concentrations of kavalactones, it does not markedly affect their bioavailability. Hence, any differences between an ethanolic or an aqueous extract in terms of the propensity of kava to cause liver damage is not because of differing kavalactone bioavailabilities.

Traditional kava beverage consumption and liver function tests in a predominantly Tongan population in Hawaii

PURPOSE

To determine the effects of traditionally prepared kava beverages on the liver function tests of regular kava beverage consumers in a population of Tongan and non-Tongan residents of Hawaii (Oahu).

METHODS

The liver function tests of 31 healthy adult kava drinkers were compared against a control group of 31 healthy adult non-kava drinkers. Subjects were recruited from the general population, a kava bar, and Tongan kava drinking circles. The liver function profile included AST, ALT, ALP, GGT, and bilirubin (total and direct). Other tests included total protein, albumin, and screens for viral hepatitis and hemochromatosis when indicated.

RESULTS

Chronic kava beverage consumption was associated with elevation of GGT in 65% of the kava drinkers versus 26% in the controls (P = .005). ALP was elevated in 23% of kava drinkers versus 3% in the controls (P = .053).

CONCLUSION

Heavy kava beverage consumption was associated with significantly elevated GGT levels.

Cognitive impairment in Aboriginal people with heavy episodic patterns of alcohol use

BACKGROUND

With chronic alcohol abuse, cognitive studies suggest that progressive cognitive decline may precede more serious and irreversible neurological syndromes. The early detection of cognitive impairment may therefore aid in the prevention of permanent brain damage. Despite the devastating consequences of alcohol abuse among Aboriginal Australians, the effects on brain function have never been studied in this population and a lack of appropriate assessment tools has prevented the development of such research.

AIMS

To determine the impact of long-term and heavy episodic alcohol use on cognitive function in Aboriginal people.

DESIGN

Cross-sectional comparing heavy episodic alcohol users with non-alcohol users.

SETTING

Two remote Aboriginal communities in north-east Arnhem Land, northern Australia.

SUBJECTS

The control group consisted of 24 non-drinkers (15 males, nine female) and the heavy episodic group consisted of 20 people (19 males, one female) who had been drinking alcohol in a heavy episodic style (median 14 drinks per occasion) for a mean of 8.9 years (SD = 5.0).

MEASUREMENTS

Interview to obtain demographic information, substance abuse history and symptoms of mental health and wellbeing, together with a computerized cognitive assessment battery (CogState Ltd).

FINDINGS

Compared with non-drinkers, heavy episodic drinkers showed reduced psychomotor speed (P = 0.04) and reduced accuracy when performing tasks of attention (P = 0.045), working memory (P = 0.04), implicit memory (P = 0.03) and associate learning and memory (P = 0.001).

CONCLUSIONS

Specific cognitive abnormalities that suggest frontostriatal abnormalities and have been observed in association with chronic alcoholism in other populations were observed among Aboriginal Australians who were heavy episodic alcoholic users.

Safety review of kava (Piper methysticum) by the Natural Standard Research Collaboration

This systematic review discusses the proposed uses, dosing parameters, adverse effects, toxicology, interactions and mechanism of action of kava. The widespread concern regarding the potential hepatotoxicity of kava is discussed. A recommendation is made to consolidate and analyse available reports and to continue postmarket surveillance in an international repository to prevent duplicates and promote collection of thorough details at the time of each report so that any association with kava is clearly defined.

Altered mental status and ataxia secondary to acute Kava ingestion

Kava has traditionally been used for a variety of purposes in the tropical islands of Polynesia but is becoming more frequently available in the United States health supplement market due to its calming effects in patients with anxiety. The side effect profile is poorly known but has recently gained the attention of the Food and Drug Administration (FDA). Although hepatitis and liver failure have been described with chronic ingestion, the effects of acute overdose are poorly described. We present a case of acute Kava overdose resulting in altered mental status and ataxia similar to that seen with ethanol intoxication.