A Case of Metformin-Associated Lactic Acidosis

Metformin is a US FDA-approved oral anti-hyperglycemic medication used to treat non-insulin-dependent diabetes mellitus (NIDDM). Metformin, a biguanide drug, works by reducing glucose production in the liver, decreasing intestinal absorption, and improving insulin sensitivity, leading to lower blood glucose levels. Metformin is generally considered to be a medication with a good safety profile and high tolerability. However, metformin therapy is associated with an uncommon but potentially serious complication known as metformin-associated lactic acidosis (MALA), which is marked by severe lactic acid accumulation in the bloodstream. This case introduces an elderly female with multiple comorbidities who presented with confusion, malaise, and lethargy. Her laboratory findings revealed acute renal failure, severe metabolic acidosis, and significantly elevated lactic acid levels consistent with sepsis and possibly MALA. Aggressive resuscitation with fluids and sodium bicarbonate was initiated. Antimicrobial drugs were started for urinary tract infections. She subsequently required endotracheal intubation with invasive ventilation, pressor support, and continuous renal replacement therapy. Her condition gradually improved over several days. The patient ultimately recovered, and at the time of discharge, metformin was discontinued, and a sodium-glucose cotransporter-2 (SGLT-2) inhibitor was initiated. This case underscores the relevance of MALA as a potential complication of metformin therapy, particularly in patients with underlying kidney disease or other risk factors. Timely detection and prompt management of MALA can prevent progression to a critical stage and thus avoid potentially fatal outcomes.

Hypoglycemia-Induced Basal Ganglia Infarct: A Rare Case of Metformin Toxicity in a Hemodialysis Patient

Metformin is the preferred agent in type 2 diabetes due to its efficacy, safety profile, cardioprotective benefits, weight loss, and accessibility in the market. However, Metformin should be prescribed with caution in patients with renal dysfunction and is contraindicated in those with a glomerular filtration rate (GFR) of less than 30 mL/min. Though extremely rare, accumulation of metformin due to poor renal clearance can cause metformin toxicity and subsequently cause lactic acidosis and hypoglycemia. The incidence is estimated at less than 10 events per 100,000 patients. Hypoglycemia has been shown to induce ischemic strokes in previous case reports; however, only one other case control study has shown hypoglycemia-induced strokes in the setting of metformin toxicity. Herein, we present a rare case of hypoglycemia-induced ischemic stroke from metformin toxicity, in a patient undergoing maintenance hemodialysis. Our case report illustrates an extremely rare case of metformin toxicity that caused a hypoglycemic-induced ischemic infarct.

Clinical presentations and prognosis of metformin-associated lactic acidosis patients in the intensive care unit: A 20-year survey

METHODS

We retrospectively analyzed 82 adult patients with MALA admitted to the ICU over 20 years. The association between the clinical parameters and mortality post-MALA was estimated using logistic regression analysis.

RESULTS

Patients with MALA admitted to the ICU presented with clinical symptoms mainly associated with the head (40.24%), chest (41.46%), and abdomen (35.37%). Additionally, the PLL distribution significantly varied with age, APACHE II = Acute Physiology and Chronic Health Evaluation II (APACHE II) score, various laboratory parameters like nadir arterial bicarbonate level, multiple treatment modalities such as renal replacement therapy, and mortality. The overall mortality rate was 17.07%. After adjustment of age and gender, the significant predictors of mortality were APACHE II score, PLL, vasoactive support, ventilator support, and cardiopulmonary resuscitation.

CONCLUSIONS

Despite MALA being a rare event, it is necessary to evaluate its clinical characteristics, especially the associated PLL and mortality. In the current study, higher levels of APACHE II score and PLL show a greater likelihood of mortality in MALA patients.

The Role of the Nephrologist in Management of Poisoning and Intoxication: Core Curriculum 2022

Poisoning is a common problem in the United States. Acid-base disturbances, electrolyte derangements, or acute kidney injury result from severe poisoning from toxic alcohols, salicylates, metformin, and acetaminophen. Lithium is highly sensitive to small changes in kidney function. These poisonings and drug overdoses often require the nephrologist's expertise in diagnosis and treatment, which may require correction of acidosis, administration of selective enzyme inhibitors, or timely hemodialysis. The clinical and laboratory abnormalities associated with the poisonings and drug overdoses can develop rapidly and lead to severe cellular dysfunction and death. Understanding the pathophysiology of the disturbances and their clinical and laboratory findings is essential for the nephrologist to rapidly recognize the poisonings and establish an effective treatment plan. This installment of AJKD's Core Curriculum in Nephrology presents illustrative cases of individual poisonings and drug overdoses and summarizes up to date information on their prevalence, clinical and laboratory findings, pathophysiology, diagnosis, and treatment.

Extracorporeal membrane oxygenation with continuous renal replacement therapy to treat metformin-associated lactic acidosis: A case report

RATIONALE

Metformin-associated lactic acidosis (MALA) is rarely encountered, but has a high mortality rate, Conventional treatments include hemodialysis or continuous renal replacement therapy (CRRT); however, when the disease progresses to end-stage, cardiac function is significantly inhibited, circulation cannot be maintained, CRRT cannot be tolerated, V-A extracorporeal membrane oxygenation (ECMO) may be the last treatment.

PATIENT CONCERNS

The study report a rare case of MALA in an elderly female patient at the age of 72 who was admitted to hospital because of nausea for 2 days, complicated with systemic fatigue.

DIAGNOSIS

MALA was cofirmed because of patient have increased lactic acid levels, blood pH <7.2, and a history of oral metformin intake.

INTERVENTIONS

Venoarterial ECMO (V-A ECMO) combined with CRRT was initiated when circulation was still not hold after intravenous fluids and 5% sodium bicarbonate were prescribed.

OUTCOMES

V-A ECMO was then terminated after 48 hours when circulation was perserved, CRRT was discontinued when PH and lactic acid level were normal limited. etformin-associated lactic acidosis did not recur during 6 months follow-up.

LESSONS

The incidence of MALA is low, but mortality is very high. Intermittent hemodialysis or CRRT should be performed if the lactic acid level is persistently elevated. When severe circulatory dysfunction occurs and cardiac function is inhibited, V-A ECMO support should be performed immediately to maintain circulation, followed by CRRT, which may be the final measure to treat refractory MALA.

The Association of Premorbid Metformin Exposure With Mortality and Organ Dysfunction in Sepsis: A Systematic Review and Meta-Analysis

Supplemental Digital Content is available in the text.

To examine the association between premorbid metformin exposure and mortality, hyperlactatemia, and organ dysfunction in sepsis.

Clinical and Laboratory Features of Metformin Intoxication in Suicidal Patients Attending an Intensive Care Unit

Introduction

This study has been performed for the purpose of researching the complications occurred at patients who took metformin overdose in an attempt to suicide. None of the patients has the diagnosis of diabetes mellitus and never used metformin.

Materials and Methods

This retrospective cross-sectional study was carried out with 21 patients who has neither diagnosed diabetes mellitus nor taken metformin for suicide before.

Results

It was observed that there is a moderate, negative (r = -0.63) statistically significant correlation (P < 0.001) between the time of applying to the hospital and arterial blood pH at the arrival and a statistically significant positive mild correlation (P < 0.041) between applying and blood lactate level (r = 0.45), and a moderate positive (r = 0.63) and statistically significant correlation (P < 0.001) between the total metformin dose and blood lactate level at the arrival and a positive, moderate (r = 0.68) significant correlation (P < 0.001) between the creatinine and metformin dose at the arrival. Lactic acidosis has been detected at 8 of 21 patients, 6 patients were hemodialized, 2 patients needed mechanical ventilation, and 2 patients died. It is observed that there is no mortality for early hemodialized patients.

Conclusion

The most important reason of the mortality in patients who has metformin intoxication is metformin-associated lactic acidosis (MALA). It was considered that hemodialysis therapy could be effective in MALA.

Continuation of metformin use after a diagnosis of cirrhosis significantly improves survival of patients with diabetes

The risks and benefits of metformin use in patients with cirrhosis with diabetes are debated. Although data on a protective effect of metformin against liver cancer development have been reported, metformin is frequently discontinued once cirrhosis is diagnosed because of concerns about an increased risk of adverse effects of metformin in patients with liver impairment. This study investigated whether continuation of metformin after cirrhosis diagnosis improves survival of patients with diabetes. Diabetic patients diagnosed with cirrhosis between 2000 and 2010 who were on metformin at the time of cirrhosis diagnosis were identified (n = 250). Data were retrospectively abstracted from the medical record. Survival of patients who continued versus discontinued metformin after cirrhosis diagnosis was compared using the log-rank test. Hazard ratio (HR) and 95% confidence interval (CI) were calculated using Cox's proportional hazards analysis. Overall, 172 patients continued metformin whereas 78 discontinued metformin. Patients who continued metformin had a significantly longer median survival than those who discontinued metformin (11.8 vs. 5.6 years overall, P < 0.0001; 11.8 vs. 6.0 years for Child A patients, P = 0.006; and 7.7 vs. 3.5 years for Child B/C patients, P = 0.04, respectively). After adjusting for other variables, continuation of metformin remained an independent predictor of better survival, with an HR of 0.43 (95% CI: 0.24-0.78; P = 0.005). No patients developed metformin-associated lactic acidosis during follow-up.

CONCLUSION

Continuation of metformin after cirrhosis diagnosis reduced the risk of death by 57%. Metformin should therefore be continued in diabetic patients with cirrhosis if there is no specific contraindication.