Incidence and risk factors for hyperlactatemia in ED patients with acute metformin overdose.

INTRODUCTION: The goals of this study are to describe clinical characteristics and risk factors for metabolic acidosis with hyperlactatemia in emergency department (ED) patients with acute metformin overdose. METHODS: This was a secondary analysis of data from a retrospective observational cohort of adult ED patients presenting with acute drug overdose at two tertiary care hospitals over 5 years. The primary outcomes were: (1) hyperlactatemia, defined as a lactate concentration ≥ 2 mmol/L at any point during hospital admission and, (2) metformin associated lactic acidosis (MALA), defined as a lactate concentration ≥ 5 mmol/L and pH <7.35 at any point during hospital admission. RESULTS: We screened 3739 acute overdoses; 2872 met eligibility, 56 self-reported metformin overdose (57% female, mean age 55.8). Of these, 39 had measured lactate values. There was a high incidence of hyperlactatemia (56.4%); MALA was less frequent (17.9%). There were no deaths. Low serum bicarbonate was an independent clinical risk factor for hyperlactatemia (adjusted p < 0.05). Acetaminophen co-exposure was an independent clinical risk factor for MALA (OR 24.40, 95% CI 1.6-376.4). CONCLUSIONS: In ED patients with acute metformin overdose, initial hyperlactatemia is common but MALA is unusual. Acetaminophen co-exposure is a novel independent risk factor for the occurrence of MALA that deserves further investigation.

Insulin degludec overdose may lead to long-lasting hypoglycaemia through its markedly prolonged half-life.

BACKGROUND: Overdose of insulin often causes long-lasting severe hypoglycaemia. Insulin degludec has the longest duration of action among the available insulin products; thus, an overdose of insulin degludec can lead to long-lasting hypoglycaemia. In the present paper, we report the case of a woman with long-lasting hypoglycaemia attributable to insulin degludec overdose and markedly prolonged insulin degludec half-life. CASE REPORT: A 64-year-old woman with Type 2 diabetes receiving insulin therapy was taken to an emergency department because of disturbed consciousness 21 h after self-injection of 300 units of insulin degludec (4.34 units/kg). Her plasma glucose level was 2.3 mmol/l. She received repeated intravenous boluses of dextrose for 43 h with continuous intravenous dextrose infusion, but no improvement in long-lasting hypoglycaemia or consciousness was observed. Considering the possibility of adrenal insufficiency, intravenous dexamethasone was administered, and her plasma glucose levels subsequently remained above 5.5 mmol/l without intravenous dextrose boluses. She gradually regained consciousness. A total of 34 h after the overdose, her plasma immunoreactive insulin levels were markedly increased and then gradually declined over ~400 h. The insulin degludec half-life was 40.76 h. CONCLUSION: Although the reported half-life of insulin degludec in the body is ~25 h when administered in standard doses (0.4-0.8 units/kg), no study has investigated its half-life after overdose. In the present case, the half-life of insulin degludec was ~1.6 times longer than that observed with standard doses, probably leading to long-lasting hypoglycaemia. Physicians should be aware of the possibility of unexpected long-lasting severe hypoglycaemia resulting from insulin degludec overdose.

'Massive' metformin overdose.

Massive metformin overdose can cause metabolic acidosis with hyperlactatemia. A 55-year-old woman presented 5 h after multidrug overdose, including 132 g extended-release metformin. Continuous venovenous haemodiafiltration (CVVHDF) and noradrenaline were commenced due to metabolic acidosis (pH 7.0, lactate 17 mmol l-1 ) and shock. Despite 3 h of CVVHDF, her acidosis worsened (pH 6.83, lactate 24 mmol l-1 ). Intermittent haemodialysis (IHD) improved acidosis (pH 7.13, lactate 26 mmol l-1 ) but again worsened (pH 6.91, lactate 30 mmol l-1 ) with CVVHDF recommencement. IHD (12 h), CVVHDF (26 h) and vasopressor support for 7 days resulted in survival. Measured metformin concentrations were extremely high with a peak of 292 µg ml-1 at 8 h postingestion. IHD, but not CVVHDF in this case, was associated with improvement in metabolic acidosis and hyperlactataemia. Pharmacokinetic analysis of metformin concentrations found a reduced apparent oral clearance of 8.2 l h-1 and a half-life of approximately 30 h. During IHD, the apparent oral clearance increased to 22.2 l h-1 with an approximate half-life of 10 h. The impact of prolonged oral absorption from a pharmacobezoar and redistribution of metformin from peripheral sites (including erythrocytes) on the pharmacokinetic profile cannot be determined from the data available.

Pharmacokinetics of insulin disappearance after massive overdosing.

Long-term glucose supplementation is required to prevent hypoglycemia after massive insulin overdosing. We fitted the blood insulin concentration-time profile to the model: I = A·exp(-a·t) + B·exp(-b·t), where I (µU/mL) is the serum/plasma insulin concentration, A (µU/mL) and B (µU/mL) are the peak insulin concentrations of each component, a (time-1) and b (time-1) are the time constants of each component, and t (h) is the time elapsed from the peak of blood insulin level. Additional components were considered as needed. Patient 1 had auto-injected 600 U NovoRapid® 30Mix, and Patient 2 had auto-injected 300 U Novolet®R (regular) and 1,800 U NovoLet®N (NPH). We used the disappearance of therapeutic doses of the respective insulin in healthy individuals as controls, and we obtained parameters by Excel solver. In Patient 1, the parameter values were A = 1490.04 and a = 0.15 for insulin aspart and B = 60.66 and b = 0.04 for protaminated aspart. In Patient 2, the values were A = 784.45 and a = 0.38 for regular insulin and B = 395.84 and b = 0.03 for NPH. Compared with controls, the half-lives (t1/2) for insulin aspart and protaminated aspart were 4 and 2 times longer, respectively, in Patient 1. In Patient 2, the t1/2 for regular and NPH insulin were 2 and 7 times longer than those in the controls, respectively. In conclusion, the t1/2 for insulin was elongated 2 to 7 times after massive overdosing, explaining why glucose supplementation is needed for long periods in these cases.

Hemodialysis in metformin-associated lactic acidosis due to acute overdose in a metformin-naïve patient.

Metformin is a common and generally well-tolerated medication in the treatment of diabetes but rarely has been implicated as the cause for metformin-associated lactate acidosis. This is usually caused by decreased elimination from renal dysfunction but is rarely described after an acute ingestion. We present a case of an acute intentional overdose of metformin in a metformin-naïve patient without renal dysfunction. The patient gradually developed altered mental status, tachypnea, hypotension, hyperglycemia, hypoglycemia, hypothermia, and vasoplegic shock unresponsive to vasopressor support. Despite attempts at alkalinization, the patient developed a lactic acidosis with a pH of 6.9 and lactate of 33 mmol/L. Hemodialysis was performed with rapid improvement of clinical status. This case provides a clinical context in the acute setting and illustrates the rare need for extracorporeal support in this setting, which may be lifesaving.

Metformin intoxication: Vasopressin's key role in the management of severe lactic acidosis.

Vasopressin is a potent vasopressor used for improving organ perfusion during cardiac arrest, septic and catecholamine-resistant shock; with reference to this, it is useful for the treatment of vasoplegic shock because, restoring organ perfusion pressure by contraction of vascular smooth muscle through a non-catecholamine receptor pathway, it can be employed when catecholamines are ineffective. A 49-yr-old woman was admitted to the Emergency Department after having intentionally taken 95.2g of metformin, 1.6g of pioglitazone and 40 UI of insulin glargine in a suicide attempt. Despite fluid resuscitation, CVVHDF (continuous veno-venous hemodiafiltration) treatment, norepinephrine and epinephrine infusion, she developed a severe lactic acidosis and a catecholamines-refractive vasodilatory shock. Only the vasopressin infusion, in association with catecholamines, gradually stabilized the patient's hemodynamic status.

Treatment of Metformin Intoxication Complicated by Lactic Acidosis and Acute Kidney Injury: The Role of Prolonged Intermittent Hemodialysis.

Metformin intoxication with lactic acidosis, a potentially lethal condition, may develop in diabetic patients when the drug dose is inappropriate and/or its clearance is reduced. Diagnosis and therapy may be delayed due to nonspecific symptoms at presentation, with severe anion gap metabolic acidosis and elevated serum creatinine values being the most prominent laboratory findings. Confirmation requires measurement of serum metformin by high-performance liquid chromatography-tandem mass spectrometry, but this technique is available only at specialized institutions and cannot be relied on as a guide to immediate treatment. Thus, based on strong clinical suspicion, renal replacement therapy must be started promptly to achieve efficient drug clearance and correct the metabolic acidosis. However, because metformin accumulates in the intracellular compartment with prolonged treatment, a rebound in serum concentrations due to redistribution is expected at the end of dialysis. We report a case of metformin intoxication, severe lactic acidosis, and acute kidney injury in a diabetic patient with pre-existing chronic kidney disease stage 3, treated effectively with sustained low-efficiency dialysis. We discuss the pathophysiology, differential diagnosis, and treatment options and highlight specific pharmacokinetic issues that should be considered in selecting the appropriate modality of renal replacement therapy.

[Advance of Forensic Research in Insulin Poisoning].

Insulin as a common clinical hypoglycemic agent can effectively control serves to lower the concentration of blood glucose. However, insulin overdose can lead to death. In the whole fatal cases of insulin overdose, medical accident is the most common, followed by suicide. Though insulin homicide is extremely rare, it deserves great attention. Though there are some researches about insulin poisoning on forensic toxicology and pathology, it is still a difficult task in forensic practice. In this paper, the mechanism of death, pathological changes, detection methods and diagnose criteria of insulin overdose will be discussed in the view of forensic toxicology and pathology. We hope that this paper could enhance relative knowledges of insulin poisoning for medical examiners.

Post-mortem analysis of lactate concentration in diabetics and metformin poisonings.

Lactate is produced in carbohydrate metabolism under anaerobic conditions. Lactic acidosis occurs when the production of lactate exceeds its removal. In post-mortem (PM) context, the lactic acidosis is difficult to interpret due to unknown pathophysiological factors prior to death and PM changes that may affect the lactate levels. We evaluated 1865 medico-legal autopsy cases where the quantitation of glucose, lactate, and ketone bodies was performed as a part of the cause of death (CoD) investigation. Lactate was shown to ascend in a logarithmic manner as the PM interval increased until a plateau was achieved approximately after 8-10 days PM, and the elevation was caused mainly by PM changes. The lactate level was higher than the mean in cases where the CoD was diabetes mellitus type 2 (DM2) or metformin poisoning. Although there was a correlation between metformin and lactate levels, our findings suggest the DM2 and its complications were the cause for elevated lactate levels rather than metformin, since the lactate levels were similar in DM2-associated deaths where no metformin was detected. Elevated lactate levels in PM samples rather referred to metabolic disturbances often caused by DM2. An assay to detect D-lactate in PM samples was described.

Lacticemia After Acute Overdose of Metformin in an Adolescent Managed Without Intravenous Sodium Bicarbonate or Extracorporeal Therapy.

Metformin-associated lactic acidosis or lacticemia has been widely reported as an adverse drug effect in diabetic patients with other significant comorbidities and in acute overdose in adults. Lacticemia has been reported twice in a previously healthy pediatric population, both of which were suicide attempts and required hemodialysis. We report a case of a 17-year-old, nondiabetic, healthy adolescent girl with metformin-associated lacticemia who intentionally overdosed on metformin, had no coingestants, and was treated only with crystalloids. Furthermore, she did not require intravenous bicarbonate administration or extracorporeal removal.

[Non usual cases of hypoglycaemia--hypoglycaemia factitia]. / Neobvyklé prípady hypoglykémie--hypoglycaemia factitia.

Hypoglycaemia factitia means also in recent time serious diagnostic and therapeutic problem in medical clinical practice, whereby often repeating episodes of serious hypoglycaemia in patients with diabetes mellitus, but also in patients without diabetes mellitus could be very difficult do resolve. First unsuccessful diagnosis implicit from wrong chose of examination algorithm, can lead to unidentified surgical interventions as are laparotomy and pancreatectomy, respectively. Hypoglycaemia factitia is considered to be one of many manifestations of so called Münchhausen's syndrome for that is typical acting of diabetic patient with goal to intentionally making hypoglycaemia or within suicidal attempt of patient on the basis psychological disease with intention to attract attention of surrounding community to himself due to application of insulin or sulfonylurea drugs. Diagnostic and therapeutic process could be in the case of hypoglycaemia factitia extremely difficult as from time side, than from health and also from economical side and that why necessary to approach with maximum responsibility.

Fatal metformin overdose: case report and postmortem biochemistry contribution.

Metformin is an oral antihyperglycemic agent used in the management of type 2 diabetes mellitus. Lactic acidosis from metformin overdose is a rare complication of metformin therapy and occurs infrequently with therapeutic use. Fatal cases, both accidental and intentional, are extremely rare in clinical practice. Metformin is eliminated by the kidneys, and impaired renal function can result in an increased plasma concentration of the drug. In this report, we describe an autopsy case involving a 70-year-old woman suffering from diabetes mellitus and impaired renal function who received metformin treatment. Metformin concentrations in the peripheral blood collected during hospitalization and femoral blood collected during autopsy were 42 and 47.3 µg/ml, respectively. Lactic acidosis (29.10 mmol/l) was objectified during hospitalization. Furthermore, postmortem biochemistry allowed ketoacidosis to be diagnosed (blood ß-hydroxybutyrate, 10,500 µmol/l). Death was attributed to lactic acidosis due to metformin intoxication. Increased plasma concentrations of the drug were attributed to severely impaired renal function. The case emphasizes the usefulness of performing exhaustive toxicology and postmortem biochemistry towards the more complete understanding of the pathophysiological mechanisms that may be involved in the death process.

Review of the lethal mechanism of insulin poisoning and the characteristic of forensic identification.

Insulin, as the only hypoglycemic hormone in the body, plays a key role in blood sugar control. However, excessive insulin intake can lead to insulin poisoning and even death, which often occurs in clinical and forensic work. At present, some researches on insulin poisoning have been carried out at home and abroad, however, it seems that the mechanism and forensic characteristics of insulin poisoning are not clear and complete. Therefore, in this paper, we reviewed the potential mechanism of insulin poisoning, the methods of insulin detection and the forensic identification of poisoning cases, aiming at providing services for the forensic identification of insulin poisoning.

Use of Intravenous Lipid Emulsion Therapy and Insulin in a Case of Tarka Intoxication.

INTRODUCTION: Tarka (trandolapril/verapamil hydrohloride extended-release) is a fixed-dose combination antihypertensive drug formed from verapamil hydrochloride and trandolapril. Toxicologic manifestations of Tarka overdose are altered mental status, bradycardia, hypotension, atrioventricular block (first-degree), hyperglycemia, metabolic acidosis, and shock. CASE PRESENTATION: We report a case of Tarka toxicity in a 2-year-old girl who presented with altered mental status, cardiogenic shock, hypotension, bradycardia, severe metabolic acidosis, hyperglycemia, and first-degree atrioventricular block. We started fluid resuscitation, epinephrine, norepinephrine, and insulin. Because of the patient's hyperlactatemia and hypotension despite standard therapies, we initiated intravenous lipid emulsion (ILE) therapy, after which her condition improved promptly. DISCUSSION: Tarka overdose may be life-threatening as it can cause cardiogenic shock. In our patient, the regression of lactate elevation in a short time with ILE therapy and the improvement of her general condition highlight the importance of ILE. CONCLUSIONS: ILE is an alternative treatment method for acute lipophilic drug intoxications, such as Tarka.

Is it really possible to kill with insulin without leaving traces? From lifesaver to killer, the issues surrounding the analytical characterization of postmortem insulin illustrated by an exemplary case.

Evidence of an insulin overdose is very complicated in the medico-legal field. The analysis and subsequent interpretation of results is complex, especially when treating postmortem blood samples. The instability of insulin, the special pre-analytical conditions and the absence of specific analytical methods has led most laboratories not to analyze insulin in their routine with a consequent underestimation of cases. This paper aims to assess the difficulties associated with the analytical characterization of insulin by describing a case that typically represents most of the inconveniences encountered following a suspected insulin overdose. The case concerns a man found dead at home by his brother. After an external examination, which did not reveal a specific cause of death, toxicological analysis was requested which did not reveal any substance of toxicological interest. Only 9 months later, it was reported to the toxicologist that the subject was diabetic, on insulin lispro treatment and that three empty syringes were found next to his body. Following analysis by LC-high-resolution mass spectrometry, the presence of insulin lispro at a concentration of 1.1 ng/mL, a therapeutic concentration, was evidenced. Despite the low concentration found, overdose cannot be excluded and this paper will describe the criteria evaluated to reach this conclusion. This case highlights that the interpretation of a postmortem insulin concentration is very complex and requires the evaluation of various elements including the circumstances of death, the subject's medical history, the interval between death and sampling and the sample storage.

A retrospective study of 29 fatal cases of insulin overdose.

PURPOSE: To summarize recent cases of fatal insulin poisoning both domestically and internationally, thereby offering valuable insights for the forensic identification of insulin overdose cases. METHODS: Literature published since 2000 on fatal insulin overdose were systematically searched and screened. Data encompassing variables such as year, age, sex, cause of death, scene conditions, occupations, medical histories of victims and perpetrators, autopsy timing, dosage and administration methods, forensic pathology, and toxicological analysis, were compiled for rigorous statistical analysis. RESULTS: Among the 29 fatal cases of insulin poisoning, suicides and homicides accounted for 55.2 % and 41.4 %, respectively. Precisely 34.5 % of victims or perpetrators were associated with the medical industry, 27.6 % had diabetes, and 24.1 % had mental illnesses such as depression. Intravenous injection resulted in quicker death than did subcutaneous injection. In some cases, immunohistochemical staining of insulin and protamine at injection sites yielded positive results. The average molar ratio of insulin to C-peptide in post-mortem blood was 13.76 ± 5.167, indicating a significant diagnostic value for insulin poisoning. CONCLUSION: Assessment of cases of fatal insulin overdose should be thorough, incorporating case investigation, scene examination, medical records review, autopsy findings, pathological examinations, and laboratory tests, alongside considering the condition of the body and timing of death autopsy. Using mass spectrometry to detect insulin proves valuable, particularly in cases of poor body preservation.

Multi-modal brain imaging showing brain damage to the orbitofrontal cortex and left hemisphere, in a case of prolonged hypoglycemia-induced transient hemiplegia followed by persistent encephalopathy.

A 21-year-old left-handed male patient was admitted with a 19-h history of coma after substantial insulin injection for suicide attempt. Although the patient recovered from coma 3 days after injury, he experienced transient hemiplegia followed by permanent brain damage. Electroencephalogram (EEG), brain magnetic resonance imaging (MRI), and brain single-photon emission computed tomography (SPECT) identified the localization of this dysfunction, but consistency between clinical symptoms and brain images changed depending on the course of treatment. Transient hemiplegia corresponded to abnormal waveforms on EEG and decreased cerebral blood flow on SPECT, whereas persistent dysfunctions corresponded to abnormal brain regions on MRI and SPECT.

Suicide commitment with metformin: our experience with five cases.

Biguanides can function as oral antihyperglycemic drugs. They were used for diabetes mellitus or prediabetes treatment over the last nine decades, but they lost their popularity in 1970s because of phenformin and regained with metformin. For metformin, the most common side effects are diarrhea and dyspepsia, occurring in up to 30% of patients. The most important and serious side effect is lactic acidosis. Phenformin was removed from the markets before 1970, because it caused lactic acidosis in 40-65 patients in 100,000 patient-years. Metformin causes lactate accumulation only in patients who have hepatic failure, renal failure or in patients who attempt suicide with high dosage of drugs. In this report, we present five patients who used high doses of metformin for suicide attempt.

Octreotide for the treatment of hypoglycemia after insulin glargine overdose.

BACKGROUND: Intentional insulin glargine overdose is rarely reported in the literature, but usually results in prolonged hypoglycemia requiring intensive care unit admission. OBJECTIVE: We report a case of using octreotide to treat prolonged hypoglycemia after a large insulin glargine overdose. CASE REPORT: A 56-year-old man with type 2 diabetes mellitus presented to the Emergency Department after a multidrug overdose including up to 3,300 units insulin glargine. He required admission to the intensive care unit for mechanical ventilation and blood-glucose monitoring every 30 to 60 min. He received a continuous dextrose infusion for >100 h for persistent hypoglycemia. Octreotide, a somatostatin analogue, was given on day 4 of admission in an attempt to inhibit any insulin secretion from the pancreas that might be occurring in response to the dextrose infusion and to minimize the amount of fluid being given. After three doses, improvements in the patient's blood glucoses were seen, however, this could have coincided with complete absorption of the insulin. CONCLUSIONS: Prolonged hypoglycemia often occurs after large overdoses of insulin glargine due to a depot effect at the site of injection. Octreotide is a potential adjunctive treatment to dextrose in patients with a functioning pancreas.