Severe hypokalaemia with paralysis induced by small doses of liquorice

Liquorice Toxicity: A Comprehensive Narrative Review

BACKGROUND

Renowned since ancient times for its medical properties, liquorice is nowadays mainly used for flavoring candies or soft drinks. Continuous intake of large amounts of liquorice is a widely known cause of pseudo-hyperaldosteronism leading to hypertension and hypokalemia. These manifestations are usually mild, although in some cases may generate life-threatening complications, i.e., arrhythmias, muscle paralysis, rhabdomyolysis, and coma. In addition, liquorice has an important estrogenic-like activity.

METHODS

We summarized the current knowledge about liquorice and reviewed 104 case reports in both the English and Italian languages from inception to June 2023 concerning complications due to an excess of liquorice intake.

RESULTS

In contrast to most published data, female sex and old age do not appear to be risk factors. However, hypertension and electrolyte imbalance (mainly hypokalemia) are prevalent features. The detection of glycyrrhetinic acid in blood is very uncommon, and the diagnosis is essentially based on an accurate history taking.

CONCLUSIONS

Although there is not a significant mortality rate, liquorice toxicity often requires hospitalization and therefore represents a significant health concern. Major pharmaceutical drug regulatory authorities should solicit public awareness about the potentially dangerous effects caused by excessive use of liquorice.

Heart Toxicity Related to Herbs and Dietary Supplements: Online Table of Case Reports. Part 4 of 5

BACKGROUND

The purpose of this review was to create an online research summary table of heart toxicity case reports related to dietary supplements (DS; includes herbs).

METHODS

Documented PubMed case reports of DS appearing to contribute to heart-related problems were used to create a "Toxic Table" that summarized the research (1966 to April, 2016, and cross-referencing). Keywords included "herb," "dietary supplement," and cardiac terms. Case reports were excluded if they were herb combinations (some exceptions), Chinese herb mixtures, teas of mixed herb contents, mushrooms, poisonous plants, self-harm (e.g. suicide), excess dose (except vitamins/minerals), drugs or illegal drugs, drug-herbal interactions, and confounders of drugs or diseases. The spectrum of heart toxicities included hypertension, hypotension, hypokalemia, bradycardia, tachycardia, arrhythmia, ventricular fibrillation, heart attack, cardiac arrest, heart failure, and death.

RESULTS

Heart related problems were associated with approximately seven herbs: Four traditional Chinese medicine herbs - Don quai (Angelica sinensis), Jin bu huan (Lycopodium serratum), Thundergod vine or lei gong teng (Tripterygium wilfordii Hook F), and Ting kung teng (Erycibe henryi prain); one an Ayruvedic herb - Aswagandha, (Withania somnifera); and two North American herbs - blue cohosh (Caulophyllum thalictroides), and Yohimbe (Pausinystalia johimbe). Aconitum and Ephedra species are no longer sold in the United States. The DS included, but are not limited to five DS - bitter orange, caffeine, certain energy drinks, nitric oxide products, and a calming product. Six additional DS are no longer sold. Licorice was the food related to heart problems.

CONCLUSION

The online "Toxic Table" forewarns clinicians, consumers and the DS industry by listing DS with case reports related to heart toxicity. It may also contribute to Phase IV post marketing surveillance to diminish adverse events that Government officials use to regulate DS.

Herb-drug interactions: an overview of the clinical evidence

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

Cardiovascular pharmacotherapy and herbal medicines: the risk of drug interaction

Use of herbal medicines among patients under cardiovascular pharmacotherapy is widespread. In this paper, we have reviewed the literature to determine the possible interactions between herbal medicines and cardiovascular drugs. The Medline database was searched for clinical articles published between January 1996 and February 2003. Forty-three case reports and eight clinical trials were identified. Warfarin was the most common cardiovascular drug involved. It was found to interact with boldo, curbicin, fenugreek, garlic, danshen, devil's claw, don quai, ginkgo, papaya, lycium, mango, PC-SPES (resulting in over-anticoagulation) and with ginseng, green tea, soy and St. John's wort (causing decreased anticoagulant effect). Gum guar, St. John's wort, Siberian ginseng and wheat bran were found to decrease plasma digoxin concentration; aspirin interactions include spontaneous hyphema when associated with ginkgo and increased bioavailability if combined with tamarind. Decreased plasma concentration of simvastatin or lovastatin was observed after co-administration with St. John's wort and wheat bran, respectively. Other adverse events include hypertension after co-administration of ginkgo and a diuretic thiazide, hypokalemia after liquorice and antihypertensives and anticoagulation after phenprocoumon and St. John's wort. Interaction between herbal medicine and cardiovascular drugs is a potentially important safety issue. Patients taking anticoagulants are at the highest risk.

A simple and rapid approach to hypokalemic paralysis

Hypokalemia with paralysis (HP) is a potentially reversible medical emergency. It is primarily the result of either hypokalemic periodic paralysis (HPP) caused by an enhanced shift of potassium (K(+)) into cells or non-HPP resulting from excessive K(+) loss. Failure to make a distinction between HPP and non-HPP could lead to improper management. The use of spot urine for K(+) excretion rate and evaluation of blood acid-base status could be clinically beneficial in the diagnosis and management. A very low rate of K(+) excretion coupled with the absence of a metabolic acid-base disorder suggests HPP, whereas a high rate of K(+) excretion accompanied by either metabolic alkalosis or metabolic acidosis favors non-HPP. The therapy of HPP requires only small doses of potassium chloride (KCl) to avoid rebound hyperkalemia. In contrast, higher doses of KCl should be administered to replete the large K(+) deficiency in non-HPP.

An unusual cause of hypokalemic paralysis: chronic licorice ingestion

Long-term licorice ingestion is a well-known cause of secondary hypertension and hypokalemia. Nevertheless, its initial presentation with a very severe degree of hypokalemia and paralysis is exceedingly rare. We report an elderly Asian man who presented to the emergency department with marked muscle weakness that progressed to paralysis. His blood pressure was 160/96 mm Hg. The major biochemical abnormalities were hypokalemia (plasma K+ concentration, 1.8 mmol/L) and metabolic alkalosis (HCO - 3 , 36 mmol/L). His renal potassium excretion was higher (transtubular potassium gradient of 9). Plasma renin activity and aldosterone concentration were suppressed and cortisol concentration was normal. A detailed history revealed that he had ingested tea flavored with 100 g of natural licorice root containing 2.3% glycyrrhizic acid daily for 3 years. Note that renal potassium wasting and hypertension persisted for 2 weeks after discontinuing licorice consumption along with KCl supplement and spironolactone. Long-term licorice ingestion should be kept in mind as a cause of paralysis with an extreme degree of hypokalemia to avoid missing this recognizable and curable medical disorder.

Herbal medicine

Generalized statements about herbal medicines are nonsensical, and each remedy has to be evaluated on its own merits. Some herbal treatments can be shown to have a favorable risk-benefit profile, but for most herbal medicines the data are insufficient to determine whether they do more good than harm. The research required to fill the gaps in present knowledge should have a high priority.

Adverse effects of unconventional therapies in the elderly: A systematic review of the recent literature

Unconventional therapies are increasingly popular, not least in populations of elderly individuals. This review summarizes the evidence regarding the risk unconventional therapies may entail for the elderly. Computerized literature searches were performed to locate all reports with original data on this topic. Most of the evidence found was anecdotal by nature and thus has obvious limitations. The results show that elderly patients can suffer harm from unconventional therapies. Herbal treatments are associated most frequently with adverse events. They can cause both direct toxicity and unwanted herb-drug interactions. Acupuncture, spinal manipulation and even massage therapy have also been implicated. Indirect risks exist if unconventional therapies are employed as a substitute for conventional treatments. It is concluded that unconventional therapies are not risk-free for elderly patients. All parties involved ought to be educated with a view of minimizing this risk, and more research is needed to increase our understanding of this area.

Use of herbal therapies by adults seen in an ambulatory care research setting: an exploratory survey

OBJECTIVE

To identify and characterize patterns of use of herbal products among patients participating in selected research clinics.

DESIGN

Survey of three National Institutes of Health (NIH) ambulatory care research clinics.

SUBJECTS

Convenience sample of 490 adult patients (168 male, 322 female) attending rheumatology, liver, and endocrinology/metabolic research clinics.

RESULTS

Of the patients surveyed, 16.7%: (n = 82) reported using herbs. There were no significant sociodemographic differences between herb and nonherb users. Indications for herb use differed among the disease groups; patients in the endocrine and rheumatology clinics were taking herbs predominantly for "energy" or "wellness"; those attending the liver clinic tended to use herbal therapies as treatment for their disease. Mean and median monthly expenditure for herbal products was $30 and $10, respectively. There was a significant positive correlation between number of herbs used and use of other dietary supplements (p < 0.0001).

CONCLUSIONS

One in six patients in ambulatory clinical research settings may be taking herbal products in addition to prescribed treatment. This figure is lower than in the general population, possibly because the patients may stop using herbs when participating in a research project. Although empirical evidence on the beneficial or adverse effects of herb therapy alone or in combination with drug therapies is limited, clinical researchers should be aware of the potential for confounding clinical trial results.

Liquorice and its health implications

This article presents an overview of the health implications of liquorice. Liquorice has beneficial applications in the medicinal and the confectionery sectors; the substance, therefore, is both widely available and commercially attractive. However, the ingestion of liquorice, and/or its active metabolites, can sometimes produce an acquired form of apparent mineralocorticoid excess (AME) syndrome, expressed as sodium retention, potassium loss and suppression of the renin-angiotensin-aldosterone system, in addition to clinical consequences such as raised blood pressure and oedema. Moreover, these metabolic changes, the mechanisms underlying which are highlighted in the accompanying text, are associated with a number of additional clinical symptoms. Considering the easy availability of liquorice itself and also of other products containing its active metabolites, it is quite possible that the health burden of liquorice-induced morbidity could be substantial. Healthcare practitioners need to be fully aware of the risks in view of a large number of reports in the literature concerning its toxicity.

Hypokalaemic paralysis

Hypokalaemic paralysis is a relatively uncommon but potentially life-threatening clinical syndrome. If recognised and treated appropriately, patients recover without any clinical sequellae. The syndrome of hypokalaemic paralysis represents a heterogeneous group of disorders characterised clinically by hypokalaemia and acute systemic weakness. Most cases are due to familial or primary hypokalaemic periodic paralysis; sporadic cases are associated with numerous other conditions including barium poisoning, hyperthyroidism, renal disorders, certain endocrinopathies and gastrointestinal potassium losses. The age of onset, race, family history, medications, and underlying disease states can help in identifying the cause of hypokalaemic paralysis. Initial therapy of the patient with hypokalaemic paralysis includes potassium replacement and search for underlying aetiology. Further management depends on the aetiology of hypokalaemia, severity of symptoms, and duration of disease. This review presents the differential diagnosis for hypokalaemic paralysis and discusses management of the syndrome.

Herbal medicine in the emergency department: a primer for toxicities and treatment

Herbal therapies are very safe, and side effects are uncommon. Side effects requiring ED treatment are rare and would most likely involve an allergic reaction or toxic effect from improper administration of the herb. However, a working knowledge of possible side effects of herbal therapies can be helpful in those rare instances. Simple treatment options with herbal teas are also suggested as an adjunct to medical therapies in certain instances.

Primary aldosteronism

The basic clinical pathophysiology of primary aldosteronism (PAL) was described by Conn in terms of autonomous production of aldosterone, secondary suppression of renin and development of hypertension with hypokalaemic alkalosis. Conn recognised a normokalaemic form of the syndrome and suggested that it might masquerade as essential hypertension and be not uncommon. This was hotly disputed at the time, and normokalaemic PAL considered rare until recently, and, as a consequence, overlooked. The advent of a simple screening test, the aldosterone-renin ratio, led to recognition that normokalaemic forms are not uncommon. In fact, PAL may be the commonest specifically treatable and potentially curable form of hypertension so far identified. In all patients with PAL confirmed by lack of suppressibility ("autonomy") of aldosterone production, Familial Hyperaldosteronism Type I (FH-I, glucocorticoid-remediable hyperaldosteronism, reviewed elsewhere in this issue) should first be excluded by dexamethasone suppression or genetic testing. Capable of causing fatal stroke in young people affected by this dominantly inherited disorder, it can be reversed by doses of glucocorticoids such as dexamethasone which partially suppress endogenous ACTH without producing "steroid" side-effects. The remaining varieties of PAL may eventually also be shown to have a genetic basis, but are currently treated either by excision of a solitary aldosterone-secreting tumour or by antagonism of aldosterone's action in the renal tubule. It is possible that both adrenal cortices are genetically predisposed to overproduction of aldosterone in all varieties of PAL, whether because of anomalous regulation of aldosterone secretion or because of a tendency towards hyperplasia and neoplasia. Aldosterone-producing adenomas (APA's) can be divided into two main subtypes based on morphology and biochemical behaviour. The first subtype to be morphologically and biochemically characterised is composed predominantly of fasciculata-like cells and is unresponsive to angiotensin II (ALL-U-APA). The more recently characterised subtype is composed predominantly of glomerulosa-like cells, is responsive to angiotensin II (AII-R-APA) and could previously have been misdiagnosed as bilateral hyperplasia. The renin gene is often overexpressed in the second variety of adenoma, and in surrounding non-tumorous cortex, and the two subgroups show different allelic frequencies for RFLP's of the constitutive renin gene and the constitutive ANP gene locus. Unilateral, solitary, benign adrenal cortical adenomas producing aldosterone (APA's) represent a potentially surgically curable form of hypertension. Adrenal venous sampling (AVS) should always be performed because APA's are biochemically recognisable by adrenal venous steroid measurement before they are identifiable by computerised tomography or scintigraphy, and adrenal masses seen on CT may not be responsible for PAL. The secretory activity of adrenal masses must therefore be established by AVS before surgical removal. Discovery of an adrenal mass on CT requires formulation of a plan, whether or not it is found to be secreting hormones in excess. Independently of the treatment of the patient's hypertension, an apparently nonfunctioning adrenal mass ("incidentaloma") should be removed if 2.5 cm or more in diameter, because of the risk of cancer. Smaller masses require long-term follow-up. Primary aldosteronism not lateralising on AVS should be treated with low dose spironolactone, or with amiloride. For any such patients intolerant of medical treatment, laparoscopic removal of the adrenal showing higher production of aldosterone on AVS is an option worthy of consideration.The resultant reduction in mass of tissue autonomously secreting aldosterone should improve hypertension, as aldosterone productions falls below a critical level, and may even be curative in the short, medium or long term, depending on the rate of growth and activity of au

Glycyrrhizic acid in liquorice--evaluation of health hazard

Literature on case reports, clinical studies and biochemical mechanisms of the sweet-tasting compound glycyrrhizic acid in liquorice was critically reviewed to provide a safety assessment of its presence in liquorice sweets. A high intake of liquorice can cause hypermineralocorticoidism with sodium retention and potassium loss, oedema, increased blood pressure and depression of the renin-angiotensin-aldosterone system. As a consequence, a number of other clinical symptoms have also been observed. Glycyrrhizic acid is hydrolysed in the intestine to the pharmacologically active compound glycyrrhetic acid, which inhibits the enzyme 11 beta-hydroxysteroid dehydrogenase (in the direction of cortisol to cortisone) as well as some other enzymes involved in the metabolism of corticosteroids. Inhibition of 11 beta-hydroxysteroid dehydrogenase leads to increased cortisol levels in the kidneys and in other mineralocorticoid-selective tissues. Since cortisol, which occurs in much larger amounts than aldosterone, binds with the same affinity as aldosterone to the mineralocorticoid receptor, the result is a hypermineralocorticoid effect of cortisol. The inhibitory effect on 11 beta-hydroxysteroid dehydrogenase is reversible; however, the compensatory physiological mechanisms following hypermineralocorticoidism (e.g. depression of the renin-angiotensin system) may last several months. It is not possible, on the basis of existing data, to determine precisely the minimum level of glycyrrhizic acid required to produce the described symptoms. There is apparently a great individual variation in the susceptibility to glycyrrhizic acid. In the most sensitive individuals a regular daily intake of no more than about 100 mg glycyrrhizic acid, which corresponds to 50 g liquorice sweets (assuming a content of 0.2% glycyrrhizic acid), seems to be enough to produce adverse effects. Most individuals who consume 400 mg glycyrrhizic acid daily experience adverse effects. Considering that a regular intake of 100 mg glycyrrhizic acid/day is the lowest-observed-adverse-effect level and using a safety factor of 10, a daily intake of 10 mg glycyrrhizic acid would represent a safe dose for most healthy adults. A daily intake of 1-10 mg glycyrrhizic acid/person has been estimated for several countries. However, an uneven consumption pattern suggests that a considerable number of individuals who consume large amounts of liquorice sweets are exposed to the risk of developing adverse effects.

Hypertension encephalopathy after liquorice ingestion

A 15-year-old boy is reported who developed a hypertension encephalopathy after ingestion of 0.5 kg liquorice candy. He recovered completely in the course of 5 months.

Hypokalemic paralyses: a review of the etiologies, pathophysiology, presentation, and therapy

Acute hypokalemic paralysis is an uncommon cause of acute weakness. Morbidity and mortality associated with unrecognized disease include respiratory failure and death. Hence, it is imperative for physicians to be knowledgeable about the causes of hypokalemic paralysis, and consider them diagnostically. The hypokalemic paralyses represent a heterogeneous group of disorders with a final common pathway presenting as acute weakness and hypokalemia. Most cases are due to familial hypokalemic paralysis; however, sporadic cases are associated with diverse underlying etiologies including thyrotoxic periodic paralysis, barium poisoning, renal tubular acidosis, primary hyperaldosteronism, licorice ingestion, and gastrointestinal potassium losses. The approach to the patient with hypokalemic paralysis includes a vigorous search for the underlying etiology and potassium replacement therapy. Further therapy depends on the etiology of the hypokalemia. Disposition depends on severity of symptoms, degree of hypokalemia, and chronicity of disease.

The determination of glycyrrhizin in selected UK liquorice products

The glycyrrhizin contents of 42 samples of liquorice-containing confectionery, health products and raw materials have been determined by a standard (AOAC) HPLC technique. Confectionery levels ranged between 0.26 and 7.9 mg g-1, whilst contents in health products were 0.30-47.1 mg g-1, the highest values being measured for throat pearls. Six geographically diverse samples of liquorice root contained similar (22.2-32.3 mg g-1) glycyrrhizin contents. Highest levels of glycyrrhizin were found in liquorice block (44-98 mg g-1) and extract powder (79-113 mg g-1). These analyses enable a mean daily intake of glycyrrhizin to be calculated for the UK. The figure (1 mg) is lower than those reported for the US and Belgium (3 and 5 mg, respectively). The significance of the levels of glycyrrhizin in UK confectionery, and the estimated daily exposure thereto, is discussed in the context of existing data on liquorice-induced toxicity.

Severe hypokalemic rhabdomyolysis due to ingestion of liquorice during Ramadan

A 62-year-old man was admitted with severe hypokalemia following ingestion of a modest amount of liquorice during the Islamic holy month of Ramadan. Hypokalemia was associated with typical electrocardiographic changes, marked acid-base disturbance and complicated by rhabdomyolysis. All abnormalities improved with normalisation of serum potassium. The serum creatine kinase isoenzymes (CK-total and MB) returned to normal over a prolonged period. The potential danger of ingesting liquorice even in small amounts over short periods, and the role of concomitant diuretic therapy with the additional factor of fasting during Ramadan in precipitating hypokalemia during liquorice ingestion are discussed.

Teratogenicity study of ammonium glycyrrhizinate in the Sprague-Dawley rat

Ammonium glycyrrhizinate (AG), a commercially used salt of glycyrrhizic acid, was administered in the drinking-water to Sprague-Dawley rats on days 7-17 of pregnancy. The actual intakes were 0, 21.33 +/- 1.22, 238.75 +/- 17.50 and 679.94 +/- 69.87 mg AG/kg body weight/day for groups 0, 1, 2 and 3, respectively. AG caused polydipsia in the dams. Foetuses from the treated litters did not present an increase in external malformations, a decrease in weight or a decrease in the degree of ossification. However, there was a slight but significant increase in embryolethality and in the prevalence of external haemorrhages. Skeletal examination revealed a dose-related increase in minor anomalies, especially in the sternebral variants. Renal ectopy also increased significantly at the highest dose. These results indicate that the possible embryotoxicity of aromatizing compounds should be considered.

Severe hypokalaemia from kaolin and morphine abuse

A 34 year old man, registered disabled as a result of muscle weakness, was admitted to hospital because of increasing weakness. He had profound hypokalaemia and admitted to taking up to 1400 ml of kaolin and morphine mixture daily. After considerable potassium replacement muscle power recovered completely. The hypokalaemia is likely to have been caused by the combination of liquorice extract and sodium bicarbonate in kaolin and morphine.

Diuretic therapy and exercise performance

Drugs that induce an increased urine flow are used both legitimately (treatment of hypertension and oedema) and otherwise (rapid weight loss) in sports and exercise. There are 5 major categories of diuretic drugs based on their mechanisms and loci of action. Common to all classes is hypohydration, which has been shown to have an array of adverse effects on performance, including impaired strength, power and endurance. Postural hypotension can be particularly troublesome in the elderly. Also common to all diuretics, except those interfering with the aldosterone mechanism in the distal nephron, is hypokalaemia. Severe symptomatic hypokalaemia (serum K+ concentration less than 3.0 mmol/L) is rare except in clinical situations in which additional hypokalaemic factors are present. Moderate levels of hypokalaemia (serum K+ concentration 3.0 to 3.5 mmol/L) can increase the risk of adverse reactions as has been shown in a variety of prospective clinical studies. Hypokalaemia has effects on cardiac rhythm, muscle function and integrity, local blood flow, carbohydrate metabolism, and the blood lipid profile. Performance studies generally show diminished exercise tolerance in direct proportion to the degree of hypohydration induced. This is not the case, however, in a clinical setting of compromised cardiopulmonary function, in which diuresis has direct and indirect inotropic effects which augment exercise tolerance and decrease symptoms. The ability of the carbonic anhydrase inhibitor, acetazolamide, to induce a hyperventilatory response to the obligatory metabolic acidosis is taken advantage of in mountaineering to prevent or ameliorate the symptoms of acute mountain sickness, thereby improving exercise performance at high altitude. It is suggested that in clinical situations in which the use of a diuretic is considered appropriate, every effort be made to maintain or restore the serum concentration and the total body store of potassium to normal. To some degree this can be accomplished through diet, although potassium chloride supplements or potassium-sparing diuretics or diuretic combinations may be necessary.

Anorexia nervosa, liquorice and hypokalaemic myopathy

A patient with a past history of anorexia nervosa developed a hypokalaemic myopathy following a 'flu-like illness. Although she was apparently in remission from anorexia nervosa, the diet was found to be markedly abnormal with an excessive ingestion of liquorice and a low potassium salt intake. The clinical features and investigations, including muscle biopsy, are described. The patient is compared, with 2 reported cases of liquorice-induced myopathy, and the relationship between anorexia nervosa, liquorice and hypokalaemic myopathy is discussed.