Extreme hypermagnesemia caused by an overdose of magnesium-containing cathartics

Pearls and Oysters: Reversible Postpartum Pseudo-Coma State Associated With Magnesium Therapy: A Report of 2 Cases

Magnesium (Mg) competes with calcium in normal synaptic transmission, inhibiting neurotransmitter release. As a drug, it is usually given as a treatment for eclampsia and pre-eclampsia. Two eclamptic pregnant women treated with Mg developed a pseudo-coma state immediately after emergency Caesarian Section. The clinical presentation was flaccid quadriparesis, areflexia, an absence of absent respiratory effort and vestibular-ocular reflexes, but with preserved pupillary responses. Decremental responses on repetitive nerve stimulation were found in both women. Recovery was obtained after cessation of the Mg. The persistence of pupillary reflexes in the absence of reflexes involving striated muscles was an important clinical clue, indicating neuromuscular junction dysfunction.

Systematic review on the use of activated charcoal for gastrointestinal decontamination following acute oral overdose

INTRODUCTION

The use of activated charcoal in poisoning remains both a pillar of modern toxicology and a source of debate. Following the publication of the joint position statements on the use of single-dose and multiple-dose activated charcoal by the American Academy of Clinical Toxicology and the European Association of Poison Centres and Clinical Toxicologists, the routine use of activated charcoal declined. Over subsequent years, many new pharmaceuticals became available in modified or alternative-release formulations and additional data on gastric emptying time in poisoning was published, challenging previous assumptions about absorption kinetics. The American Academy of Clinical Toxicology, the European Association of Poison Centres and Clinical Toxicologists and the Asia Pacific Association of Medical Toxicology founded the Clinical Toxicology Recommendations Collaborative to create a framework for evidence-based recommendations for the management of poisoned patients. The activated charcoal workgroup of the Clinical Toxicology Recommendations Collaborative was tasked with reviewing systematically the evidence pertaining to the use of activated charcoal in poisoning in order to update the previous recommendations.

OBJECTIVES

The main objective was: Does oral activated charcoal given to adults or children prevent toxicity or improve clinical outcome and survival of poisoned patients compared to those who do not receive charcoal?  Secondary objectives were to evaluate pharmacokinetic outcomes, the role of cathartics, and adverse events to charcoal administration. This systematic review summarizes the available evidence on the efficacy of activated charcoal.

METHODS

A medical librarian created a systematic search strategy for Medline (Ovid), subsequently translated for Embase (via Ovid), CINAHL (via EBSCO), BIOSIS Previews (via Ovid), Web of Science, Scopus, and the Cochrane Library/DARE. All databases were searched from inception to December 31, 2019. There were no language limitations.  One author screened all citations identified in the search based on predefined inclusion/exclusion criteria. Excluded citations were confirmed by an additional author and remaining articles were obtained in full text and evaluated by at least two authors for inclusion. All authors cross-referenced full-text articles to identify articles missed in the searches. Data from included articles were extracted by the authors on a standardized spreadsheet and two authors used the GRADE methodology to independently assess the quality and risk of bias of each included study.

RESULTS

From 22,950 titles originally identified, the final data set consisted of 296 human studies, 118 animal studies, and 145 in vitro studies. Also included were 71 human and two animal studies that reported adverse events. The quality was judged to have a Low or Very Low GRADE in 469 (83%) of the studies. Ninety studies were judged to be of Moderate or High GRADE. The higher GRADE studies reported on the following drugs: paracetamol (acetaminophen), phenobarbital, carbamazepine, cardiac glycosides (digoxin and oleander), ethanol, iron, salicylates, theophylline, tricyclic antidepressants, and valproate. Data on newer pharmaceuticals not reviewed in the previous American Academy of Clinical Toxicology/European Association of Poison Centres and Clinical Toxicologists statements such as quetiapine, olanzapine, citalopram, and Factor Xa inhibitors were included. No studies on the optimal dosing for either single-dose or multiple-dose activated charcoal were found. In the reviewed clinical data, the time of administration of the first dose of charcoal was beyond one hour in 97% (n = 1006 individuals), beyond two hours in 36% (n = 491 individuals), and beyond 12 h in 4% (n = 43 individuals) whereas the timing of the first dose in controlled studies was within one hour of ingestion in 48% (n = 2359 individuals) and beyond two hours in 36% (n = 484) of individuals.

CONCLUSIONS

This systematic review found heterogenous data. The higher GRADE data was focused on a few select poisonings, while studies that addressed patients with unknown and or mixed ingestions were hampered by low rates of clinically meaningful toxicity or death.  Despite these limitations, they reported a benefit of activated charcoal beyond one hour in many clinical scenarios.

Fatal Hypermagnesemia Due to Laxative Use

We report a case of fatal hypermagnesemia in a 53-year-old woman admitted for acute exacerbation of chronic obstructive pulmonary disease and with a history of chronic constipation treated regularly with magnesium-containing laxatives. On admission, her magnesium level was 2.0mg/dL, which rose to a peak of 10.8mg/dL despite hydration and diuresis in the presence of a normal kidney function. Continuous renal replacement therapy was promptly initiated, which reduced her serum magnesium levels, but her condition continued to deteriorate precipitously progressing to shock leading to oligoanuric renal failure, and she died 2 days later. A review of the literature shows that though rare and often unsuspected, severe hypermagnesemia frequently results in death even in individuals with normal renal function despite renal replacement therapy. In patients with constipation, retention of magnesium-based laxative in the gut apparently serves as a reservoir for continuous magnesium absorption and contributes to mortality.

Hypermagnesemia disturbances in rats, NO-related: pentadecapeptide BPC 157 abrogates, L-NAME and L-arginine worsen

AIM

Stable gastric pentadecapeptide BPC 157, administered before a high-dose magnesium injection in rats, might be a useful peptide therapy against magnesium toxicity and the magnesium-induced effect on cell depolarization. Moreover, this might be an NO-system-related effect. Previously, BPC 157 counteracts paralysis, arrhythmias and hyperkalaemia, extreme muscle weakness; parasympathetic and neuromuscular blockade; injured muscle healing and interacts with the NOS-blocker and NOS-substrate effects.

MAIN METHODS

Assessment included magnesium sulfate (560 mg/kg intraperitoneally)-induced muscle weakness, muscle and brain lesions, hypermagnesemia, hyperkalaemia, increased serum enzyme values assessed in rats during and at the end of a 30-min period and medication (given intraperitoneally/kg at 15 min before magnesium) [BPC 157 (10 µg, 10 ng), L-NAME (5 mg), L-arginine (100 mg), alone and/or together]. In HEK293 cells, the increasing magnesium concentration from 1 to 5 mM could depolarize the cells at 1.75 ± 0.44 mV.

KEY FINDINGS

L-NAME + magnesium-rats and L-arginine + magnesium-rats exhibited worsened severe muscle weakness and lesions, brain lesions, hypermagnesemia and serum enzymes values, with emerging hyperkalaemia. However, L-NAME + L-arginine + magnesium-rats exhibited all control values and normokalaemia. BPC 157 abrogated hypermagnesemia and counteracted all of the magnesium-induced disturbances (including those aggravated by L-NAME or L-arginine). Thus, cell depolarization due to increasing magnesium concentration was inhibited in the presence of BPC 157 (1 µM) in vitro.

SIGNIFICANCE

BPC 157 likely counteracts the initial event leading to hypermagnesemia and the life-threatening actions after a magnesium overdose. In contrast, a worsened clinical course, higher hypermagnesemia, and emerging hyperkalaemia might cause both L-NAME and L-arginine to affect the same events adversely. These events were also opposed by BPC 157.

Serum magnesium concentrations in patients receiving sodium picosulfate and magnesium citrate bowel preparation: an assessment of renal function and electrocardiographic conduction

BACKGROUND

We performed a post hoc analysis of two clinical trials to assess whether sodium picosulfate and magnesium (Mg(2+)) citrate (Prepopik(®) [P/MC]), a dual-action bowel preparation for colonoscopy, has an impact on serum Mg(2+) levels and cardiac electrophysiology. Although rare, hypermagnesemia has been reported in patients consuming Mg(2+)-containing cathartics, especially patients who are elderly and have renal impairment.

METHODS

Data were analyzed from two prospective, Phase III, randomized, assessor-blinded, active-control, multicenter, pivotal studies that investigated split-dose/day-before P/MC. Serum Mg(2+) and creatinine clearance (CrCl) were measured at screening, on the day of colonoscopy, and 24-48 hours, 7 days, and 4 weeks after colonoscopy; electrocardiograms also were obtained at these time points.

RESULTS

In total, 304 patients received split-dose P/MC and 294 patients received day-before P/MC. Only 10% of the patients had serum Mg(2+) above the upper limit of normal (1.05 mmol/L) on the day of colonoscopy. There was a slight inverse correlation between CrCl and Mg(2+) levels on the day of colonoscopy; however, even at the lowest CrCl, serum Mg(2+) remained below clinically significant levels of 2.0 mmol/L. Increases in serum Mg(2+) were transient, with levels returning to baseline within 24-48 hours, regardless of renal function. No patients with elevated Mg(2+) experienced a corrected QT (QTc) interval >500 milliseconds or a QTc interval increase of ≥60 milliseconds from baseline. P/MC had no impact on PR or QRS interval.

CONCLUSION

P/MC produces little impact on serum Mg(2+) levels with no clinically significant effect on cardiac conduction in patients, including those with mild-to-moderate renal impairment.

Magnesium Toxicity-Induced Ileus in a Postpartum Patient Treated for Preeclampsia With Magnesium Sulphate

Hypermagnesemia is a rare and under-recognized cause of paralytic ileus. We report a case of a 21-year-old primigravida who was managed aggressively for preeclampsia and presented with postpartum paralytic ileus. Detailed history was employed to consider hypermagnesemia-induced ileus as the working diagnosis, and the patient improved with correction of the electrolyte imbalance. Hypermagnesemia-induced lethargy, decreased reflexes, muscle weakness, flaccid paralysis, respiratory muscle paralysis, and cardiac arrest are well-described; however, intestinal smooth muscle dysfunction leading to paralytic ileus has never been reported in the setting of magnesium use for peripartum preeclampsia management.

Magnesium basics

As a cofactor in numerous enzymatic reactions, magnesium fulfils various intracellular physiological functions. Thus, imbalance in magnesium status-primarily hypomagnesaemia as it is seen more often than hypermagnesaemia-might result in unwanted neuromuscular, cardiac or nervous disorders. Measuring total serum magnesium is a feasible and affordable way to monitor changes in magnesium status, although it does not necessarily reflect total body magnesium content. The following review focuses on the natural occurrence of magnesium and its physiological function. The absorption and excretion of magnesium as well as hypo- and hypermagnesaemia will be addressed.

Serum magnesium and atherogenic lipid fractions in type II diabetic patients of Lahore, Pakistan

This study was conducted to determine the prevalence of hypomagnesemia and its effect on the lipid profile of local type II diabetic patients. For this purpose, 219 diabetic patients and 100 age-matched control subjects were enrolled. Blood samples of the subjects were analyzed for fasting glucose, Mg, triglyceride, total cholesterol, HDL-cholesterol, and LDL-cholesterol. Results showed that mean serum values of these parameters were differing in diabetic patients as compared to control subjects. The reference range of serum magnesium in healthy controls was 1.2-4.4 mg/dl. Mean serum magnesium in diabetic patients was significantly lower as compared to healthy subjects (1.6 ± 0.23 mg/dl vs. 2.8 ± 0.8 mg/dl). Among diabetic patients, 143 (65.3%) had serum magnesium level below 1.7 mg/dl (hypomagnesemia). The corresponding figure for control subjects was 11 (11%). The difference was significant (p < 0.01). Diabetes mellitus patients with current hyperglycemic status had significantly lower serum Mg as compared to euglycemic patients (p = 0.05). Serum Mg in diabetic patients was correlated with all lipid parameters. Among them, HDL-cholesterol was significantly (p < 0.05) positively correlated (r = 0.34), while total cholesterol and LDL-cholesterol was negatively correlated, albeit non-significantly, with serum Mg. These results demonstrate that hypomagnesemia is accompanied by atherogenic alterations in the lipid profiles of type II diabetic patients of Lahore, Pakistan.

Drug-induced alterations in Mg2+ homoeostasis

Magnesium (Mg2+) balance is tightly regulated by the concerted actions of the intestine, bone and kidneys. This balance can be disturbed by a broad variety of drugs. Diuretics, modulators of the EGFR (epidermal growth factor receptor), proton pump inhibitors, antimicrobials, calcineurin inhibitors and cytostatics may all cause hypomagnesaemia, potentially leading to tetany, seizures and cardiac arrhythmias. Conversely, high doses of Mg2+ salts, frequently administered as an antacid or a laxative, may lead to hypermagnesaemia causing various cardiovascular and neuromuscular abnormalities. A better understanding of the molecular mechanisms underlying the adverse effects of these medications on Mg2+ balance will indicate ways of prevention and treatment of these adverse effects and could potentially provide more insight into Mg2+ homoeostasis.

Deliberate overdose with Epsom salts

Epsom salts contains the active compound magnesium sulfate and is used most commonly as a laxative. There are potential serious toxic effects, including cardiac arrest, when the serum concentration rises above therapeutic values. We present a case of deliberate self poisoning with a large quantity of Epsom salts, resulting in a toxic serum magnesium concentration of 9.7 mmol/l (0.70-1.0 mmol/l). Clinical features included limb weakness, vomiting and confusion, with a subsequent rapid deterioration in level of consciousness and bradydysrhythmia. There was no significant response to calcium gluconate, so haemodialysis was urgently arranged. The patient made a full recovery. Hypermagnesaemia is unusual in patients with normal renal function. Although clinical severity does not always correlate with serum magnesium values, risk of cardiac arrest occurs with concentrations >6 mmol/l. Initial treatment is supportive. Dialysis should be considered when life threatening features or renal impairment are present.

Successful resuscitation of hypermagnesaemic asystolic cardiac arrest with the use of early transvenous cardiac pacemaker: a case report

A 63 year old woman presented to the emergency department (ED) with 1 week of progressive dyspnoea, constipation, and generalized weakness. She had undergone spinal fustion surgery 10 days previously, and had a history of chronic renal insufficiency. The patient had been using milk of magnesia and magnesium citrate in unknown amounts to alleviate her constipation over this time frame. During her ED stay she became progressively hypotensive and bradycardic, and despite aggressive resuscitative measures she suffered an asystolic arrest 1 hour into her ED course. She was resuscitated with conventional therapy, but her haemodynamic profile did not improve significantly until transvenous cardiac pacing was employed. Her magnesium level was 10.4 mmol/l. Treatment of magnesium overload has focused upon haemodialysis, forced diuresis, and the use of intravenous calcium salts. Case reports have previously documented survival of moderately to severely ill patients when these modalities have been used. Likewise, failure of resuscitation despite use of these methods has been previously noted. To our knowledge, this is the first reported case clearly demonstrating the efficacy of transvenous cardiac pacing to successfully resuscitate a patient upon whom multiple vasopressors, fluids, and calcium previously had no clear effect.

Fatal hypermagnesemia caused by an Epsom salt enema: a case illustration

The authors describe a case of fatal hypermagnesemia caused by an Epsom salt enema. A 7-year-old male presented with cardiac arrest and was found to have a serum magnesium level of 41.2 mg/dL (33.9 mEq/L) after having received an Epsom salt enema earlier that day. The medical history of Epsom salt, the common causes and symptoms of hypermagnesemia, and the treatment of hypermagnesemia are reviewed. The easy availability of magnesium, the subtle initial symptoms of hypermagnesemia, and the need for education about the toxicity of magnesium should be of interest to physicians.

Hypermagnesemia-induced fatality following epsom salt gargles(1)

Hypermagnesemia is a rare cause of coma in a patient with normal renal function. When present, it is often because of iatrogenic medication overdose. We report a fatal case of chronic Epsom salt gargles for halitosis that produced a serum magnesium of 23.6 mg/dL (9.8 mmol/L) and resulted in coma. We review the wide presentation of hypermagnesemia from subtle neurologic and cardiovascular signs to the major life-threatening clinical manifestations of shock, dysrhythmias, coma, and cardiopulmonary arrest despite emergency dialysis.

Adverse effects of laxatives

Laxatives are among the most commonly used drugs or additives. Most are quite safe when used judiciously, intermittently when possible, and in the absence of contraindications. Bulking agents and nonabsorbable compounds such as lactulose can cause bloating but have very few serious adverse effects except for the allergic reaction to psyllium preparations. Osmotic laxatives containing poorly absorbable ions such as magnesium or phosphate can cause metabolic disturbances, particularly in the presence of renal impairment. However, if taken intermittently, in the absence of conditions such as ileus or bowel obstruction, they have few adverse effects. Polyethylene glycol solutions are emerging as an effective and safe mode of treatment for chronic constipation. Of stimulant laxatives, senna compounds and bisacodyl are the most commonly used. Although there are data to support the neoplastic potential of this class of drugs in in vitro studies, epidemiologic data in humans so far has not established a clear link between these laxatives and colonic neoplasia. The link between stimulant laxatives and structural changes, such as the "cathartic colon" or enteric nerve damage, is not well established either. Danthron compounds should be avoided because of hepatotoxicity.

Hypercalcemia and hypermagnesemia

Hypercalcemia and hypermagnesemia occur infrequently in small animal patients. Specific clinical signs usually do not accompany these electrolyte disorders, and their presence is often recognized only after reviewing serum chemistry profile results. The etiologies, clinical signs, and therapies for each electrolyte disorder are discussed in this article. Treatment of these disorders is aimed at correcting the underlying disease process and enhancing the removal of calcium or magnesium from the body. In severe cases, rescue therapies and resuscitative measures are required to stabilize the patient.

Hypermagnesemia following an acute ingestion of Epsom salt in a patient with normal renal function

CASE REPORT

Hypermagnesemia is a rare condition that commonly follows excessive therapeutic administration of magnesium sulfate to treat eclampsia of pregnancy. Signs and symptoms of this condition include extreme muscle weakness, loss of deep tendon reflexes, mental status depression, and cardiac dysrhythmias. Clinically significant hypermagnesemia following oral or rectal administration of magnesium containing products in patients with normal renal function is rare. We report a case of hypermagnesemia following massive Epsom salt ingestion that resulted in extreme musculoskeletal weakness and altered mentation.

Efficacy of magnesium citrate cathartic in pediatric toxic ingestions

STUDY OBJECTIVE

To investigate the efficacy of magnesium citrate in reducing gastrointestinal transit time of activated charcoal in children.

DESIGN

A prospective, randomized, clinical comparison of four magnesium doses.

SETTING

Urban children's hospital emergency department.

PARTICIPANTS

Children aged 1 month to 6 years who presented for management of an acute toxic ingestion.

INTERVENTION

Each child received 1 g/kg activated charcoal combined with a randomly assigned dose of a 6% solution of magnesium citrate: 0 mL/kg, 4 mL/kg (standard recommended dose), 6 mL/kg, or 8 mL/kg. The primary outcome measure was the interval to first activated charcoal-containing stool, which was determined by follow-up telephone call or review of the medical record.

RESULTS

Sixty-four children were enrolled. Median times to first charcoal stool were 19.5 hours (0 mL/kg), 13.0 hours (4 mL/kg), 14.0 hours (6 mL/kg), and 12.0 hours (8 mL/kg). Intergroup differences were significant by Kruskal-Wallis analysis of variance (P = .0035).

CONCLUSION

Magnesium citrate reduces gastrointestinal transit times of activated charcoal stools when administered to children who receive activated charcoal for a toxic ingestion. Further study is needed to determine the clinical value of this reduction.

Magnesium and its therapeutic uses: a review

Magnesium has been reported as an effective medical therapy in an expanding array of conditions. Evidence investigating magnesium's use is presented, with a number of studies suggesting it should be seriously considered in such conditions as ischemic heart disease, cardiac arrhythmias, and asthma. Magnesium balance and metabolism are briefly reviewed, and then various hypotheses are presented that may explain magnesium's physiologic mechanisms of action, most likely involving calcium and potassium flux across cellular membranes in smooth muscle. In a number of the conditions to be discussed, it has been uncertain whether magnesium administration serves the purpose of merely correcting an underlying deficiency state or of utilizing a specific pharmacologic effect of magnesium. Magnesium deficiency is a relatively common condition, and predisposing factors as well as recent methods for assessing total body stores of magnesium are discussed. Physicians should be familiar with the numerous conditions and therapeutics that are risk factors for an underlying magnesium deficiency and in which empiric magnesium replacement should be considered. Guidelines for administration of parenteral magnesium are presented with specific focus on the low risk of adverse effects, as suggested by the large and rapid dosing regimens used in many of the clinical studies discussed here.

New whole blood analyzers and their impact on cardiac and critical care

Miniaturized whole blood biosensors, patient-focused hospitals, and rising expectations of patients and physicians are shifting laboratory diagnostics to the point of care. Expanding transplantation and intensive care are increasing the need for rapid test results. Whole blood analysis improves accuracy, eliminates centrifugation, reduces response time, and conserves blood volume. Several hand-held, and over 20 portable or transportable whole blood instruments are now available. Criteria for instrument evaluation include test menus, point-of-care features, analysis time, on-site performance, and information integration. Whole blood analyzers measure several vital indicators (pO2, pCO2, pH, hematocrit, K+, Ca2+, Na+, Cl-, glucose, and lactate) simultaneously in less than 2 min with less than 200 microliters of whole blood. Other in vitro tests are available (Mg2+, osmolality, CO2 content, urea nitrogen, beta-hydroxybutyrate, hemoglobin, coagulation) or under development (HCO3- phosphorus). Some can be monitored in vivo (O2 saturation, pO2, pCO2, pH, glucose) or ex vivo. The clinical impact is demonstrated by ionized calcium, now established in importance for cardiac and neurologic problems, and ionized magnesium, a promising new measurement. The hybrid laboratory (a composite of conventional clinical laboratory and patient-focused testing), performance maps, and quality paths facilitate implementation of new whole blood analyzers for optimal support of cardiac and critical care, and improved patient outcomes (prospects).

Serum magnesium concentrations after repetitive magnesium cathartic administration

Severe hypermagnesemia has been reported by several authors after multiple doses of magnesium-containing cathartic are administered during management of a toxic ingestion. To evaluate the frequency and magnitude of serum magnesium elevations after the use of repetitive magnesium catharsis, we prospectively evaluated 102 patients who received multiple doses of magnesium citrate as a part of treatment of an overdose. Commonly ingested substances for which repetitive cathartic was administered were tricyclic antidepressants in 47%, aspirin in 17%, and phenytoin in 10%. For each case, serial electrolytes, blood urea nitrogen, creatinine, calcium and magnesium were obtained. Mean initial serum magnesium concentration was 1.8 +/- .03 mEq/L. After a mean 960 mL of magnesium citrate (9.22 g magnesium), final mean serum magnesium concentration was 2.5 +/- .05 mEq/L. Forty-seven patients (47%) developed an elevated (greater than 2.4 mEq/L) serum magnesium concentration, with 12 greater than 3.0 mEq/L. No correlation was found between total quantity of magnesium citrate administered and the increment in serum magnesium concentration. Our data indicate that serum magnesium concentrations consistently rise after repetitive magnesium citrate use. However, the magnitude of this rise appears modest. The elevation in serum magnesium concentration does not correlate with the quantity of magnesium administered. We conclude that with close monitoring, repetitive magnesium citrate can be administered without inducing severe hypermagnesemia (serum magnesium concentration greater than 5.0 mEq/L).

Management of toxicoses

This article provides information on the detoxification of and supportive care for poisoned animals. Involved are measures to control life-threatening manifestations of toxicoses, to remove agents from the digestive tract, skin, or eyes, and to promote removal of systemically absorbed toxicants. The use of these methods is often of paramount importance in an effort to limit organ damage and to enable a poisoned animal to survive.