Metformin-associated lactic acidosis: reinforcing learning points.

Metformin-associated lactic acidosis (MALA) carries a high mortality rate. It is seen in patients with type 2 diabetes on metformin or patients who attempt suicide with metformin overdose. We present the case of a man in his early 20s with type 2 diabetes, hypertension and hypothyroidism who presented with agitation, abdominal pain and vomiting after ingesting 50-60 g of metformin; he developed severe lactic acidosis (blood pH 6.93, bicarbonate 7.8 mEq/L, lactate 28.0 mEq/L). He was managed with intravenous 8.4% bicarbonate infusion and continuous venovenous haemodiafiltration. He also developed acute renal failure (ARF) requiring intermittent haemodialysis and continuous haemodiafiltration. MALA is uncommon and causes changes in different vital organs and even death. The primary goals of therapy are restoration of acid-base status and removal of metformin. Early renal replacement therapy for ARF can result in rapid reversal of the acidosis and good recovery, even with levels of lactate normally considered to be incompatible with survival.

Prolonged coma resulting from massive levothyroxine overdose and the utility of N-terminal prohormone brain natriuretic peptide (NT-proBNP).

INTRODUCTION: Levothyroxine overdose rarely results in systemic toxicity. We report a case of intentional levothyroxine overdose with a delayed onset coma and delirium lasting two weeks. CASE SUMMARY: A 72-year-old female ingested 12 mg levothyroxine. Initially, she was drowsy but quickly recovered and was well for the following two days. On day-3 post-overdose her mental state gradually deteriorated. She presented to the hospital with agitation, confusion and dyspnoea. Initial vital signs: P128 bpm, BP132/67 mmHg, temperature 38 °C and SpO2 97%RA. Features suggesting thyroid storm were present: fever >38 °C, tachycardia and persistent coma. Serum T4 and T3 were >150 pmol/L (normal: 8-16) and >30.8 pmol/L (normal: 3.2-6.1), respectively. These remained elevated for 11 days. She was treated with propranolol, propylthiouracil and cholestyramine. She remained intubated for two weeks without sedation. Her conscious state improved on day-13, coinciding with normalisation of serum T4. Normal cognition was regained four days later. N-terminal pro-brain natriuretic peptide (NT ProBNP) concentration was increased during coma and peaked 2 days prior to Glasgow Coma Score improving. DISCUSSION: Our case demonstrates features of thyrotoxicosis and thyroid storm with coma after massive levothyroxine overdose. Coma was associated with an increase in NT-proBNP concentration. This may be a potential marker for brain injury and recovery.

Clinical Toxicity of Acute Overdoses With L-Thyroxin in Children.

OBJECTIVES: L-Thyroxine ingestion is rarely seen in children; here, we report our experience of it. This study describes the clinical characteristics and laboratory findings of acute L-thyroxine ingestion in children. METHODS: This retrospective study enrolled patients treated for L-thyroxine ingestion at Kayseri Teaching Hospital between September 2013 and September 2016. Clinical characteristics and laboratory findings are described. Ethical approval was not obtained because the study was retrospective. RESULTS: The incidence of L-thyroxine ingestion was 0.07% to 1.2% per year. There were 14 patients. Twelve patients were asymptomatic, but 2 (14.2%) exhibited tachycardia and hypertension. Thyroid hormone levels were elevated in 3 patients (21.4%). Eleven patients did not require medical treatment (78.4%); 3 did. No serious complication or death was observed. CONCLUSIONS: Acute ingestion has a benign course. Serious complications are uncommon but may appear several hours or days after ingestion; therefore, patients with L-thyroxine ingestion should be followed closely for 2 weeks.

Seizure due to multiple drugs intoxication: a case report / Convulsão por causa de intoxicação por múltiplas drogas: relato de caso

Abstract The mechanism of the antidepressant effect of bupropion is not fully understood. Besides, using it in the treatment of depression, it is found to be effective in reducing withdrawal symptoms due to smoking cessation. A 28-year-old female patient with a history of depression was admitted to emergency department an hour after ingestion of bupropion, quetiapine, and levothyroxine in high doses to commit suicide. While accepting her into the Intensive Care Unit, she was awake, alert, disoriented and agitated. After 2 h, the patient had a generalized tonic-clonic seizure. The necessary treatment was given and 9 h later with hemodynamic improvement, the patients’ mental status improved. Bupropion may cause unusual behaviors such as delusions, paranoia, hallucinations, or confusion. The risk of seizure is strongly dose-dependent. We want to emphasize the importance of early gastric lavage and administration of activated charcoal.

Resumo O mecanismo do efeito antidepressivo de bupropiona ainda não está bem esclarecido. Contudo, seu uso no tratamento de depressão revelou ser eficaz para reduzir os sintomas de abstinência relacionados à cessação do tabagismo. Uma paciente do sexo feminino, 28 anos, com história de depressão, deu entrada no setor de emergência uma hora após a ingestão de bupropiona, quetiapina e levotiroxina em doses elevadas para cometer suicídio. Ao ser internada em unidade de terapia intensiva, estava acordada, alerta, desorientada e agitada. Após duas horas, apresentou uma crise tônico-clônica generalizada. O tratamento necessário foi administrado e nove horas mais tarde, com a estabilização hemodinâmica, o estado mental da paciente melhorou. Bupropiona pode causar comportamentos incomuns, incluindo delírios, paranoia, alucinações ou confusão mental. O risco de convulsão é altamente dependente da dose. Queremos enfatizar a importância da lavagem gástrica precoce e da administração de carvão ativado.

Seizure due to multiple drugs intoxication: a case report.

The mechanism of the antidepressant effect of bupropion is not fully understood. Besides, using it in the treatment of depression, it is found to be effective in reducing withdrawal symptoms due to smoking cessation. A 28-year-old female patient with a history of depression was admitted to emergency department an hour after ingestion of bupropion, quetiapine, and levothyroxine in high doses to commit suicide. While accepting her into the Intensive Care Unit, she was awake, alert, disoriented and agitated. After 2h, the patient had a generalized tonic-clonic seizure. The necessary treatment was given and 9h later with hemodynamic improvement, the patients' mental status improved. Bupropion may cause unusual behaviors such as delusions, paranoia, hallucinations, or confusion. The risk of seizure is strongly dose-dependent. We want to emphasize the importance of early gastric lavage and administration of activated charcoal.

Hypothyroidism Impairs Human Stem Cell-Derived Pancreatic Progenitor Cell Maturation in Mice.

Pancreatic progenitors derived from human embryonic stem cells (hESCs) are a potential source of transplantable cells for treating diabetes and are currently being tested in clinical trials. Yet, how the milieu of pancreatic progenitor cells, including exposure to different factors after transplant, may influence their maturation remains unclear. Here, we examined the effect of thyroid dysregulation on the development of hESC-derived progenitor cells in vivo. Hypothyroidism was generated in SCID-beige mice using an iodine-deficient diet containing 0.15% propyl-2-thiouracil, and hyperthyroidism was generated by addition of L-thyroxine (T4) to drinking water. All mice received macroencapsulated hESC-derived progenitor cells, and thyroid dysfunction was maintained for the duration of the study ("chronic") or for 4 weeks posttransplant ("acute"). Acute hyperthyroidism did not affect graft function, but acute hypothyroidism transiently impaired human C-peptide secretion at 16 weeks posttransplant. Chronic hypothyroidism resulted in severely blunted basal human C-peptide secretion, impaired glucose-stimulated insulin secretion, and elevated plasma glucagon levels. Grafts from chronic hypothyroid mice contained fewer ß-cells, heterogenous MAFA expression, and increased glucagon(+) and ghrelin(+) cells compared to grafts from euthyroid mice. Taken together, these data suggest that long-term thyroid hormone deficiency may drive the differentiation of human pancreatic progenitor cells toward α- and ε-cell lineages at the expense of ß-cell formation.

ß1-Adrenergic and M2 Muscarinic Autoantibodies and Thyroid Hormone Facilitate Induction of Atrial Fibrillation in Male Rabbits.

Activating autoantibodies to the ß1-adrenergic and M2 muscarinic receptors are present in a very high percentage of patients with Graves' disease and atrial fibrillation (AF). The objective of this study was to develop a reproducible animal model and thereby to examine the impact of these endocrine-like autoantibodies alone and with thyroid hormone on induction of thyroid-associated atrial tachyarrhythmias. Five New Zealand white rabbits were coimmunized with peptides from the second extracellular loops of the ß1-adrenergic and M2 muscarinic receptors to produce both sympathomimetic and parasympathomimetic antibodies. A catheter-based electrophysiological study was performed on anesthetized rabbits before and after immunization and subsequent treatment with thyroid hormone. Antibody expression facilitated the induction of sustained sinus, junctional and atrial tachycardias, but not AF. Addition of excessive thyroid hormone resulted in induced sustained AF in all animals. AF induction was blocked acutely by the neutralization of these antibodies with immunogenic peptides despite continued hyperthyroidism. The measured atrial effective refractory period as one parameter of AF propensity shortened significantly after immunization and was acutely reversed by peptide neutralization. No further decrease in the effective refractory period was observed after the addition of thyroid hormone, suggesting other cardiac effects of thyroid hormone may contribute to its role in AF induction. This study demonstrates autonomic autoantibodies and thyroid hormone potentiate the vulnerability of the heart to AF, which can be reversed by decoy peptide therapy. These data help fulfill Witebsky's postulates for an increased autoimmune/endocrine basis for Graves' hyperthyroidism and AF.

Antidotes to coumarins, isoniazid, methotrexate and thyroxine, toxins that work via metabolic processes.

Some toxins cause their effects by affecting physiological processes that are fundamental to cell function or cause systemic effects as a result of cellular interaction. This review focuses on four examples, coumarin anticoagulants, isoniazid, methotrexate and thyroxine from the context of management of overdose as seen in acute general hospitals. The current basic clinical pharmacology of the toxin, the clinical features in overdose and evidence base for specific antidotes are discussed. The treatment for this group is based on an understanding of the toxic mechanism, but studies to determine the optimum dose of antidote are still required in all these toxins except thyroxine, where treatment dose is based on symptoms resulting from the overdose.

Case report: clues to the diagnosis of an unsuspected massive levothyroxine overdose.

There is currently little literature pertaining to levothyroxine overdose apart from minor or accidental overdoses in the pediatric population. In particular, there is little information available on how to confidently differentiate levothyroxine overdose from endogenous causes of thyrotoxicosis when there is no history available at the time of assessment. We report a levothyroxine (15,800 mcg) and citalopram (2,460 mg) overdose in a 55-year-old woman presenting with seizure and tachycardia in which the diagnosis was not initially suspected. Clinical data, including a long history of treated hypothyroidism and lack of a goiter; and biochemical findings, such as an incompletely suppressed thyroid-stimulating hormone (TSH) level, despite a markedly elevated free thyroxine level (FT4), a normal sex hormone-binding globulin level at baseline, and an undetectable thyroglobulin, supported the diagnosis of thyrotoxicosis due to a massive exogenous thyroid hormone overdose. Treatment was given to decrease free triiodothyronine (FT3) conversion and increase thyroid hormone clearance with dexamethasone and cholestyramine. The patient made a full recovery. Levothyroxine overdose can result in subtle symptoms and signs clinically, even when in massive quantities. This can make diagnosis challenging. Biochemical features, such as the pattern of thyroid hormone elevation and thyroglobulin levels, help differentiate exogenous thyroid hormone overdose from endogenous causes of thyrotoxicosis.

[Multi-organ failure after massive Levothyroxine ingestion: case report]. / Insufficienza multiorgano da massiva ingestione volontaria di Levotiroxina: case report.

Levothyroxine is the drug of choice prescribed worldwide for the treatment of Hypothyroidism. The exact daily dosage, mode of consumption and refractoriness to therapy are still subject of discussion. The intoxication with levothyroxine is rare and with severe complications in adults; on the contrary, high prevalence and benign course is observed in pediatric age. We report the case of a 56 year-old woman, presented to the emergency department after intentional ingestion of massive levothyroxine overdose , with acute renal failure, severe disturbances of cardiovascular and central nervous system, that required intensive care support. In absence of a specific treatment, plasmapheresis has been used with good results, despite important clinical complications. In fact the clinical applications of plasmapheresis are rapidly increasing in number and scope: the plasmapheresis appears to be a very important tool for the treatment of acute and severe forms of thyrotoxicosis due to l-thyroxine intoxication.

Levothyroxine Poisoning - Symptoms and Clinical Outcome.

Levothyroxine (LT), T4, poisoning is rarely associated with a severe outcome. However, cases with significant complications have been reported. The aim of this study was to identify factors associated with symptoms of poisoning including late-onset symptoms. All enquiries to the Danish Poison Information Centre (DPIC) concerning LT poisoning between March 2007 and September 2012 were reviewed and the following parameters were recorded: age, dose, time from ingestion, multiple drug intake and symptoms. To evaluate the frequency of late-onset symptoms, a subgroup of patients without initial symptoms were contacted. A total of 181 patients were registered (112 children). Ingested LT dose ranged from 10 to 9000 mcg (median 275 mcg). A total of 29 of 181 (16%) patients were symptomatic at the time of enquiry, and there was no difference in ingested LT dose between asymptomatic and symptomatic patients, neither in children nor in adults (age 16-92 years) (p < 0.68 and p < 0.47, respectively). In total, 153 of 181 (85%) patients did not have symptoms of poisoning at the time of enquiry; however, in 9 of 21 (43%) patients, we were able to contact, late-onset symptoms existed. In none of the cases, hospital contact was needed and there were no reports of long-term sequelae. Acute LT poisoning often follows a benign course. The occurrence of symptoms appears not to be dose dependent. Late-onset symptoms seem to be common. However, all symptoms resolved spontaneously without need of medical care.

Thyroid storm caused by a chinese herb contaminated with thyroid hormones.

BACKGROUND: We report a case of thyroid storm caused by consuming a Chinese herb contaminated with thyroid hormones. CASE REPORT: A 70-year-old man presented to an emergency department after 2 days of nausea, vomiting, and weakness. Three days previously, he had started taking Cordyceps powder and "Flower Man Sang Hung" as recommended by his Chinese physician. Following admission, the patient deteriorated and was eventually diagnosed with thyroid storm complicated by rapid atrial fibrillation requiring cardioversion, intubation, and intensive care admission. The analysis of the Chinese herb "Flower Man Sang Hung" was positive for levothyroxine. The patient was extubated 11 days after admission and discharged to a rehabilitation centre after 17 days of hospitalization. The Chinese medicine physician was informed of the events. CONCLUSIONS: Herbal products can be the source of illness, medication interactions, and contamination. Awareness should be raised among Chinese medicine physicians, allopathic physicians, and their patients. Clinicians should also have a low threshold of suspicion to seek laboratory analysis of suspect substances when the cause of the clinical presentation is unclear.

[Acute poisoning with levothyroxine in own experience]. / Ostre zatrucia lewotyroksyna w materiale wlasnym.

Exposure to thyroid products is common, but acute poisonings in adults are rare. Most cases of severe toxicity are related to prolonged, repeated exposure (either inadvertent or deliberate abuse). There are a few reports of toxicity in children following large (greater than 10 mg) single ingestions. Expect significant toxicity in children and adults who have ingested more than 2 to 4 mg of levothyroxine. However, in comorbid elderly patients, the threshold may be lower. In this paper we present acute overdose of levothyroxine in nine adult patients (aged 21-44 years; mean--30.5 years); ingested doses were from 1.2 mg to 15 mg (mean--6.5 mg). Only in three cases (ingested doses were 5.6; 8.0 and 15 mg) minor and mild clinical symptoms were observed and pharmacological treatment was necessary. No severe symptoms were observed in our group. Asymptomatic clinical course in patients who ingested more than 3 mg of levothyroxine probably was related to coingestion of benzodiazepins, beta-blockers, ACE inhibitors and ethanol. Serum free triiodothyronine (T3) level of 20 pg/ml (normal, 4.1 pg/ml) was reported following an overdose of 15 mg levothyroxine in day five. Normalization was observed in day eleven.

Fibroblast growth factor 21 and thyroid hormone show mutual regulatory dependency but have independent actions in vivo.

Thyroid hormone (TH) regulates fibroblast growth factor 21 (FGF21) levels in the liver and in the adipose tissue. In contrast, peripheral FGF21 administration leads to decreased circulating levels of TH. These data suggest that FGF21 and TH could interact to regulate metabolism. In the present study, we confirmed that TH regulates adipose and hepatic FGF21 expression and serum levels in mice. We next investigated the influence of TH administration on key serum metabolites, gene expression in the liver and brown adipose tissue, and energy expenditure in FGF21 knockout mice. Surprisingly, we did not observe any significant differences in the effects of TH on FGF21 knockout mice compared with those in wild-type animals, indicating that TH acts independently of FGF21 for the specific outcomes studied. Furthermore, exogenous FGF21 administration to hypothyroid mice led to similar changes in serum and liver lipid metabolites and gene expression in both hypothyroid and euthyroid mice. Thus, it appears that FGF21 and TH have similar actions to decrease serum and liver lipids despite having some divergent regulatory effects. Whereas TH leads to up-regulation in the liver and down-regulation in brown adipose tissue of genes involved in the lipid synthesis pathway (eg, fatty acid synthase (FASN) and SPOT14), FGF21 leads to the opposite changes in expression of these genes. In conclusion, TH and FGF21 act independently on the outcomes studied, despite their ability to regulate each other's circulating levels. Thus, TH and FGF21 may modulate the availability of each other in critical metabolic states.

Thyrotoxicosis after a massive levothyroxine ingestion in a 3-year-old patient.

Most children with exploratory levothyroxine ingestions remain asymptomatic or suffer only minor effects, and most patients can be managed in the home or with supportive care in the hospital. We present a case of a 3-year-old girl who was found after a witnessed massive ingestion of levothyroxine. The patient was initially seen in an emergency department and discharged in stable condition, only to return 4 days after ingestion with thyrotoxicosis, hypertension, tachycardia, 24 hours of persistent vomiting, and clinical and laboratory evidence of dehydration. On the day of hospital admission, her thyroid-stimulating hormone was 0.018 µIU/mL (reference range, 0.6-4.5 µIU/mL); free T4 (tetraiodothyronine) was greater than 6.0 ng/dL (reference range, 0.7-2.1 ng/dL); and T3 (triiodothyronine) total was 494 ng/dL (reference range, 100-200 ng/dL). During a 3-day hospital admission, she was managed with supportive care, including intravenous fluid rehydration and antiemetics, and was ultimately discharged in good condition. The patient was followed up until 2 months after ingestion and remained asymptomatic. Although most exploratory levothyroxine ingestions suffer little to no clinical effects, serious symptoms can occur. Because serious symptoms can occur in a delayed fashion, it is important for clinicians to give proper anticipatory guidance regarding home symptom monitoring, follow-up, and reasons to return to the emergency department when patients present for medical evaluation.