Hyperlactataemia and clinical severity of acute metformin overdose

Metformin Therapy for Acne Vulgaris: A Meta-Analysis

Acne vulgaris is a common disease, which occurs in adolescents as well as adults and has a significant influence on the patient's quality of life (QoL) in every aspect. Due to resistance to standard therapies, it has become necessary to prospect for new treatment strategies. It is important to highlight that the diagnosis and treatment of the underlying cause of acne such as metabolic and hormonal disorders may significantly improve the effectiveness of acne treatment. The correlation between Insulin Resistance (IR) and acne has been proven. Both disorders share many common occurrence factors and activation pathways. Metformin, an antihyperglycemic agent, seems to be a possible therapy option, not only because of its insulin sensitizing ability but also via plenty of additional effects of this medicine. While the efficiency of metformin therapy in patients with acne and Polycystic Ovary Syndrome (PCOS) is well explored, it is still necessary to evaluate it in patients without any endocrinopathies. This meta-analysis aimed to estimate the effectiveness of oral metformin as a monotherapy in acne patients without PCOS or other endocrinopathies. Study selection was performed with included criteria such as no PCOS and other endocrinopathies diagnosed, oral administration of metformin, and metformin in monotherapy. Selected studies contained comparisons in the Global Acne Grading System (GAGS) before and after metformin therapy. Statistical analysis detected significant improvement in skin condition after treatment with metformin.

Current status and frontier tracking of clinical trials on Metformin for cancer treatment

PURPOSE

Metformin has been used clinically for more than six decades. Over time, numerous remarkable effects of metformin beyond the clinic have been discovered and discussed. Metformin has been shown to have a favorable impact on cancer therapy in addition to its clinically recognized hypoglycemic effect. However, the antitumor efficacy of metformin in humans has not been clearly demonstrated yet. Hence, a systematic analysis of the existing trials is necessary.

METHODS

Here, we retrieved clinical trials from the Clinical Trials.gov database to overview the clinical development of metformin for the treatment of cancer, analyze existing clinical results, and summarize some promising applications for specific cancer therapies.

RESULTS

The potential application of metformin contains three directions: Firstly, improvement of metabolic factors associated with treatment effects, such as insulin resistance and peripheral neuropathy. Secondly, in combination with immune checkpoint blockade effects. Finally, use it for the endocrine treatment of hormone-dependent cancers.

CONCLUSION

Although the outcomes of metformin as a repurposed agent in some trials have been unsatisfactory, it still has the potential to be used in select cancer therapy settings.

Expanding the evidence for managing metformin poisoning to support decision-making

INTRODUCTION

Metformin-associated lactic acidosis is a well-described and commonly encountered condition associated with significant morbidity and mortality. Patients with metformin-associated lactic acidosis are frequently managed in the intensive care unit with supportive care, including volume resuscitation and consideration of an extracorporeal treatment to correct metabolic acidemia and remove metformin and lactate.

EXTRACORPOREAL TREATMENTS IN POISONING WORKGROUP

The Extracorporeal Treatments in Poisoning Workgroup published evidence-based consensus recommendations in 2015 regarding the use of extracorporeal treatment in metformin toxicity. These recommendations list both clinical and biochemical indications, and they outline the rationale and evidence supporting each recommendation.

NEW RESEARCH SINCE RECOMMENDATIONS WERE PUBLISHED

Subsequent publications have provided new information regarding metformin-associated lactic acidosis and its treatment. A retrospective study showed that patients who did not meet the Extracorporeal Treatments in Poisoning Workgroup criteria for initiation of an extracorporeal treatment had a 100% survival. In patients who met the criteria, survival was approximately 75%; only 66% of these patients received an extracorporeal treatment, and this treatment did not appear to impact survival. Two other retrospective studies in patients diagnosed with metformin-associated lactic acidosis noted that extracorporeal treatments did not improve survival. However, those who received an extracorporeal treatment were more severely ill, potentially supporting a benefit from this intervention. A systematic review of patients receiving continuous kidney replacement therapy identified an overall survival that was higher than the overall survival in patients included in the Workgroup publication. This led the authors to suggest that intermittent hemodialysis may not be the preferred treatment for metformin toxicity. However, a closer look at the Workgroup data identified improved survival with each decade since the initial reports in the 1970s. Furthermore, there are multiple reports of persistent metformin-associated lactic acidosis that did not improve with standard continuous kidney replacement therapy, prompting an increase in the dosage of the extracorporeal treatment. The data supporting these observations are largely derived from retrospective studies, which have inherent biases, so prospective studies are required.

PRESCRIBING EXTRACORPOREAL TREATMENTS FOR PATIENTS WITH METFORMIN POISONING

Case-based decision-making is always necessary, but in general, we continue to follow the Extracorporeal Treatments in Poisoning Workgroup criteria because a convincing reason for changing these has not yet been presented. This includes the use of intermittent hemodialysis where possible, particularly in cases of severe poisoning. For patients with less severe poisoning or when intermittent hemodialysis is not readily available, it is reasonable to trial continuous modalities with careful observation for deterioration.

Metformin-Induced Lactic Acidosis: A Question of Time

Metformin is an oral antidiabetic largely prescribed in the treatment of type II diabetes. Overdose is associated with life-threatening lactic acidosis. We report the case of the highest metformin concentration ever described secondary to a voluntary suicidal intake. The patient developed a severe lactic acidosis and hemodynamic shock successfully treated with high-flow hemofiltration. Time to start extrarenal epuration is capital to avoid poor evolution.

Is metformin associated with acute kidney injury? A case-control study of patients with type 2 diabetes admitted with acute infection

INTRODUCTION

Despite the long-term renoprotective effects of Metformin, a recent study on data from the U.S. Food and Drug Administration reported a possible nephrotoxic effect, contributing to the development of acute kidney injury (AKI). We investigated the association between metformin and AKI in patients admitted with the AKI-prone condition of acute infection and compared results with corresponding results of other antidiabetics.

METHODS

In a nationwide register-based case-control study, we identified Danish patients with type 2 diabetes hospitalized with acute infection between 2008 and 2018. Cases of AKI had an increase in plasma creatinine ≥  × 1.5 during admission, controls did not. Antidiabetics were identified up to 6 months before admission. Odds ratio (OR) of each antidiabetic was computed in separate multiple logistic regression models adjusted for relevant medication and comorbidities and results compared.

RESULTS

We included 46,811 patients, hereof 9454 AKIs (20%) and 2186 (4.7%) severe AKIs. Overall, 56% were males, median age (IQR) was 73 (65-81). Sixty percent received metformin, 13% sulfonylurea, 31% insulin and 8% dipeptidyl peptidase-4 inhibitors (DPP-4i), with equal distribution between cases and controls. Metformin was associated with increased OR (CI) for AKI, 1.07 (1.02-1.12), equally to sulfonylurea, 1.10 (1.03-1.18) and DPP-4i, 1.11 (1.02-1.20), but not insulin, 0.99 (0.93-1.05). In severe AKI, results for metformin were 1.27 (1.25-1.40) but increased equivalently to other antidiabetics.

CONCLUSIONS

In patients with type 2 diabetes hospitalized with acute infection, metformin was not independently associated with AKI, since other antidiabetics were also significantly associated, indicating confounding by indication.

Multiple limb compartment syndrome as a manifestation of capillary leak syndrome secondary to metformin and dipeptidyl peptidase IV inhibitor overdose: A case report

RATIONALE

Capillary leak syndrome is a condition that increases systemic capillary permeability and causes characteristic manifestations such as recurrent hypovolemia, systemic edema, and hemoconcentration. Acute limb compartment syndrome is a possible complication of severe capillary leak syndrome. However, timely diagnosis and prompt treatment are challenging because of atypical presentation.

PATIENT CONCERNS

An 18-year-old woman with a history of clinical depression was admitted to our intensive care unit (ICU) because of metformin and vildagliptin overdose. She developed marked vasodilatory shock with recurrent severe hypovolemia and disseminated intravascular coagulation. After urgent hemodialysis and plasma exchange, she started to stabilize hemodynamically. However, her limbs became stone-hard with massive edema. Her serum creatinine kinase level increased to an extremely high level.

DIAGNOSIS

Extremities were distended, and her skin developed pallor with blistering. Intramuscular pressure in both forearms and lower legs was significantly elevated.

INTERVENTIONS

Decompressive fasciotomy was performed. Hemodialysis was continued because of rhabdomyolyses-induced acute kidney injury.

OUTCOMES

The patient was finally able to walk by herself at the time of hospital discharge on day 109.

LESSONS

The possibility of acute compartment syndrome should be considered in patients with marked capillary leakage, especially after aggressive fluid resuscitation. It is important to be aware of the compartment syndrome in an ICU setting because communication barriers often mask typical symptoms and make diagnosis difficult.

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.

Time to development of metformin-associated lactic acidosis

Objective: Metformin-associated lactic acidosis (MALA) is a complication of metformin overdose. Recommendations for observation time after an acute ingestion to monitor for MALA vary. The aim of this study was to characterize the time to development of MALA after an acute metformin overdose.Methods: Utilizing Crystal Reports (Version 11.0), all metformin cases reported to the Illinois Poison Center (IPC) with a National Poison Data System (NPDS) clinical effects code of "acidosis" or "anion gap" were retrospectively queried over a 14-year period (2001-2014). Demographic data, time to MALA, co-ingestants, therapeutic modality use, and case outcome were extracted. Interrater reliability was assessed using kappa analysis.Results: A total of 88 cases were identified of which 44 met criteria for MALA; 40 were acute, acute on chronic, or unknown ingestions. The remaining four were chronic ingestions which were excluded. The mean age was 41 years (range 19-79 years). Most were female (55.0%) and over half (62.5%) were acute on chronic ingestions. Hypoglycemia was seen in three ingestions of metformin only. Of the 40 MALA cases, 18 developed MALA less than or equal to 6 h after ingestion, 9 between 6-12 h, 3 after 12 h, and 10 patients had an unknown time to MALA. The only death in the cohort had MALA detected beyond the typical 6-h observation period. Of the exposures when time to MALA was known, 40% (12/30) developed MALA greater than 6 h post ingestion.Conclusion: A 6-h observation period after a single acute ingestion of metformin may be inadequate, as a significant portion of exposures developed MALA beyond this time. We recommend a minimum of 12 h of observation following an acute overdose. Further study defining prospectively the time to development of MALA may improve management of this population.

Review of Biguanide (Metformin) Toxicity

In the 1920s, guanidine, the active component of Galega officinalis, was shown to lower glucose levels and used to synthesize several antidiabetic compounds. Metformin (1,1 dimethylbiguanide) is the most well-known and currently the only marketed biguanide in the United States, United Kingdom, Canada, and Australia for the treatment of non-insulin-dependent diabetes mellitus. Although phenformin was removed from the US market in the 1970s, it is still available around the world and can be found in unregulated herbal supplements. Adverse events associated with therapeutic use of biguanides include gastrointestinal upset, vitamin B₁₂ deficiency, and hemolytic anemia. Although the incidence is low, metformin toxicity can lead to hyperlactatemia and metabolic acidosis. Since metformin is predominantly eliminated from the body by the kidneys, toxicity can occur when metformin accumulates due to poor clearance from renal insufficiency or in the overdose setting. The dominant source of metabolic acidosis associated with hyperlactatemia in metformin toxicity is the rapid cytosolic adenosine triphosphate (ATP) turnover when complex I is inhibited and oxidative phosphorylation cannot adequately recycle the vast quantity of H+ from ATP hydrolysis. Although metabolic acidosis and hyperlactatemia are markers of metformin toxicity, the degree of hyperlactatemia and severity of acidemia have not been shown to be of prognostic value. Regardless of the etiology of toxicity, treatment should include supportive care and consideration for adjunct therapies such as gastrointestinal decontamination, glucose and insulin, alkalinization, extracorporeal techniques to reduce metformin body burden, and metabolic rescue.

'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.

Hypoglycemia and severe lactic acidosis in a dog following metformin exposure

Hypoglycemia and lactic acidosis are rare complications with metformin use in humans. As metformin is not commonly used in veterinary medicine, severe adverse effects secondary to exposure are not known. Awareness of potentially life-threatening complications with metformin exposure is an important addition to the veterinary literature.

Metabolic syndrome in children and adolescents

Prevalence of metabolic syndrome in children and adolescents is increasing, in parallel with the increasing trends in obesity rates. Varying definitions of this syndrome have hindered the development of a consensus for the diagnostic criteria in the pediatric population. While pathogenesis of metabolic syndrome is not completely understood, insulin resistance and subsequent inflammation are thought to be among its main mechanistic underpinnings. Overweight and obesity are cardinal features, along with abnormal glucose metabolism, dyslipidemia, and hypertension. Other disorders associated with metabolic syndrome include fatty liver, polycystic ovarian syndrome (PCOS), and pro-inflammatory states. Prevention and management of this condition can be accomplished with lifestyle modifications, behavioral interventions, pharmacological and surgical interventions as needed.

Metformin associated lactic acidosis (MALA): clinical profiling and management

Metformin (MF) accumulation during acute kidney injury is associated with high anion gap lactic acidosis type B (MF-associated lactic acidosis, MALA), a serious medical condition leading to high mortality. Despite dose adjustment for renal failure, diabetic patients with chronic kidney disease (CKD) stage III-IV are at risk for rapid decline in renal function by whatever reason, so that MF toxicity might arise if the drug is not timely withdrawn. Sixteen consecutive patients were admitted to our Hospital's Emergency Department with clinical findings consistent with MALA. Fifteen had prior history of CKD, 60 % of them with GFR between 30 and 60 ml/min. Of these, 5 required mechanical ventilation and cardiovascular support; 3 promptly recovered renal function after rehydration, whereas 10 (62 %) required continuous veno-venous renal replacement treatment. SOFA and SAPS II scores were significantly related to the degree of lactic acidosis. In addition, lactate levels were relevant to therapeutic choices, since they were higher in dialyzed patients than in those on conservative treatment (11.92 mmol/l vs 5.7 mmol/l, p = 0.03). The overall death rate has been 31 %, with poorer prognosis for worse acidemia, as serum pH was significantly lower in non-survivors (pH 6.96 vs 7.16, p > 0.04). Our own data and a review of the literature suggest that aged, hemodynamically frail patients, with several comorbidities and CKD, are at greater risk of MALA, despite MF dosage adjustment. Moreover, renal replacement therapy rather than simple acidosis correction by administration of alkali seems the treatment of choice, based on eventual renal recovery and overall outcome.