Fulminant lactic acidosis in two patients with Type 2 diabetes treated with metformin

The Association between Metformin Therapy and Lactic Acidosis

INTRODUCTION AND OBJECTIVES

There is increasing evidence to suggest that therapeutic doses of metformin are unlikely to cause lactic acidosis. The aims of this research were (1) to formally evaluate the association between metformin therapy and lactic acidosis in published case reports using two causality scoring systems, (2) to determine the frequency of pre-existing independent risk factors in published metformin-associated lactic acidosis cases, (3) to investigate the association between risk factors and mortality in metformin-associated lactic acidosis cases, and (4) to explore the relationship between prescribed metformin doses, elevated metformin plasma concentrations and the development of lactic acidosis in cases with chronic renal impairment.

METHODS

A systematic review was conducted to identify metformin-associated lactic acidosis cases. Causality was assessed using the World Health Organisation-Uppsala Monitoring Centre system and the Naranjo adverse drug reaction probability scale. Compliance to dosing guidelines was investigated for cases with chronic renal impairment as well as the association between steady-state plasma metformin concentrations prior to admission.

RESULTS

We identified 559 metformin-associated lactic acidosis cases. Almost all cases reviewed (97%) presented with independent risk factors for lactic acidosis. The prescribed metformin dose exceeded published guidelines in 60% of cases in patients with impaired kidney function. Metformin steady-state plasma concentrations prior to admission were predicted to be below the proposed upper limit of the therapeutic range of 5 mg/L.

CONCLUSIONS

Almost all cases of metformin-associated lactic acidosis reviewed presented with independent risk factors for lactic acidosis, supporting the suggestion that metformin plays a contributory role. The prescribed metformin dose, on average, exceeded the dosing recommendations by 1000 mg/day in patients with varying degrees of renal impairment but the predicted pre-admission plasma concentrations did not exceed the therapeutic range.

Is it necessary to discontinue metformin in diabetic patients with GFR > 60 ml/min per 1.73 m2 undergoing coronary angiography: A controversy still exists?

BACKGROUND

Although metformin is not directly nephrotoxic, it has been postulated that it can impair gluconeogenesis from lactate, which may lead lactate to be accumulated under circumstances such as contrast-induced nephropathy. The present study aims to assess the role of metformin in lactate production in a group of diabetic patients with GFR > 60 ml/min per 1.73 m2undergoing coronary angiography.

METHODS

In the present randomized clinical trial, 162 metformin-treated diabetic patients were enrolled. The enlisted patients were scheduled to undergo coronary angiography at Modarres Hospital from Feb 2012 to Nov 2012. Patients were randomly allocated to continue metformin during peri-angiography period (M (+) group) or to stop the medication 24 hours prior the procedure (M (-) group). All the patients had glomerular filtration rate of >60 mL/min per 1.73 m2. Iodixanol was the only contrast media which in all patients. Metformin-associated lactic acidosis (MALA) was defined as an arterial pH <7.35 and plasma lactate concentration >5 mmol⁄L.

RESULTS

162 patients, including79 (48.7%) male and 83 (51.3%) female patients were enrolled in the study. The average of GFR was comparable in both groups (76 ml/min per 1.73 m2 in the M (+) group versus 79 ml/min per 1.73 m2 in the M (-) group, p=0.53). No significant difference was observed in the mean dose of metformin before the study between the 2 groups (2.18 tablets per day in M (+) group vs. 2.21 tablets per day in M(-) group, p=0.62).No lactic acidosis was observed in the studied groups.

CONCLUSION

In conclusion, the results of the present study indicate that metformin continuation in diabetic patients with a GFR of more than 60 ml/min per 1.73 m2 undergoing coronary angiography does not enhance the risk of MALA development.

Metformin-associated lactic acidosis: Current perspectives on causes and risk

Although metformin has become a drug of choice for the treatment of type 2 diabetes mellitus, some patients may not receive it owing to the risk of lactic acidosis. Metformin, along with other drugs in the biguanide class, increases plasma lactate levels in a plasma concentration-dependent manner by inhibiting mitochondrial respiration predominantly in the liver. Elevated plasma metformin concentrations (as occur in individuals with renal impairment) and a secondary event or condition that further disrupts lactate production or clearance (e.g., cirrhosis, sepsis, or hypoperfusion), are typically necessary to cause metformin-associated lactic acidosis (MALA). As these secondary events may be unpredictable and the mortality rate for MALA approaches 50%, metformin has been contraindicated in moderate and severe renal impairment since its FDA approval in patients with normal renal function or mild renal insufficiency to minimize the potential for toxic metformin levels and MALA. However, the reported incidence of lactic acidosis in clinical practice has proved to be very low (<10 cases per 100,000 patient-years). Several groups have suggested that current renal function cutoffs for metformin are too conservative, thus depriving a substantial number of type 2 diabetes patients from the potential benefit of metformin therapy. On the other hand, the success of metformin as the first-line diabetes therapy may be a direct consequence of conservative labeling, the absence of which could have led to excess patient risk and eventual withdrawal from the market, as happened with earlier biguanide therapies. An investigational delayed-release metformin currently under development could potentially provide a treatment option for patients with renal impairment pending the results of future studies. This literature-based review provides an update on the impact of renal function and other conditions on metformin plasma levels and the risk of MALA in patients with type 2 diabetes.

Acute renal failure and metformin-associated lactic acidosis following colonoscopy

Two patients with type 2 DM developed acute kidney injury and lactic acidosis following colonoscopy despite withholding metformin. We recommend that DM patients on metformin also withhold ACEI, ARB until their dehydration is reversed after colonoscopy. This should reduce the risk of acute renal failure (ARF) and of lactic acidosis.

Clinical evaluation of Dyslipidemia among type II diabetic patients at Public hospital Penang, Malaysia

Background

Global views emphasize the need for early; effective intervention against the atherogenic dyslipidemia associated with type 2 diabetes and metabolic syndrome to reduce the risk of premature cardiovascular diseases. Our aim was to determine the clinical practices and compliance among dyslipidemia with type II diabetes and hypertension in multiracial society.

Method(s)

Study was carried out in out-patient department of General hospital Penang over a period of ten months (Jan - Oct 2008). Study reflects the retrospective data collection covering a period of three years from Jan 2005 - Dec 2007. Universal sampling technique was used to select all the patients' undergone treatment for diabetes type II and dyslipidemia. All the concerned approvals were obtained from Clinical research Committee (CRC). Data was analyzed by using SPSS 15^®.

Result(s)

A total of 501 diabetes type 2 patients with dyslipidemia were identified in this study. The demographic data showed that 55.9% (n = 280) were female patients and 44.1% (n = 221) were males. Patients on combination therapy of metformin with other antidiabetic agent were 79%, while 21% were on monotherapy. Lovastatin was received as monotherapy in 83% of study population, while only 17% were on combination with gemfibrozil. Means of FPG and lipid profile were reduced from the initial (2005) to the latest level (2007) significantly (p < 0.001). Only 0.89% decrease in mean weight with S.D 13.1 as compared to initial S.D 12.8 after three years of Cohort. While in description 35.2% representatives gain weight with majority of males (71.5%), 52.3% with weight loss of 1-3 pounds majority (69.3%) with female respondents and rest 12.4% remains with same weight with mix gender distribution.

Conclusion

Metformin and lovastatin use among patients of type 2 diabetes and dyslipidemia is significantly improved the clinical outcomes. No significant association of metformin or lovastatin is found against the hypertension. Metformin and calcium channel blocker combination therapy was found to be the best choice in the co-treatment of diabetes and hypertension.

Metformin and lactic acidosis in patients with type 2 diabetes--from pride and prejudice to sense and sensibility

AIM

To present the cases of lactic acidosis encountered in our department among metformin-treated type 2 diabetic patients and to investigate the role of contraindications to metformin use.

METHODS

A survey of medical records of metformin-treated type 2 diabetic patients hospitalised for various medical conditions during the years 2004-2005 who exhibited elevated serum concentrations of lactic acid.

RESULTS

Seven metformin-treated type 2 diabetic patients were identified who were not attending our department and were hospitalised with elevated serum lactic acid levels (6 developed lactic acidosis). All patients had one or more contraindications to metformin use. Outcome was favourable in 6 patients, while 1 patient with hepatocellular carcinoma died of liver failure.

CONCLUSIONS

So far, metformin is one of the safest first-line oral hypoglycaemic agents. However, caution is needed to avoid patients with evident contraindications. This highlights the need for the practitioner to possess sound clinical judgement when prescribing metformin.

Defining the role of repaglinide in the management of type 2 diabetes mellitus: a review

Type 2 diabetes mellitus (T2DM) is characterized by hyperglycemia due to a combination of insulin resistance and impaired insulin secretion. The hyperglycemia is associated with an increased risk for micro- and macrovascular complications, and lowering fasting and postprandial hyperglycemia may be protective against these complications. Repaglinide is an insulin secretagogue that lowers blood glucose levels in patients with T2DM. We review the effects of repaglinide in patients with T2DM, its impact on glycemia and its non-glycemic effects, and its effects when used in special situations or patient populations. Results from randomized controlled trials, observational studies, and safety reports involving humans and published in the English-language through 1 May 2007 identified by a search in PubMed/MEDLINE were evaluated. Present knowledge indicates that repaglinide reduces fasting and postprandial hyperglycemia and the level of glycosylated hemoglobin (HbA1c) in patients with T2DM. It is at least as effective in reducing HbA1c and fasting plasma glucose as sulphonylureas, metformin, or the glitazones and in combination therapy with other drugs, repaglinide is as effective as any other combination. Some studies show a better effect of repaglinide on postprandial glycemia than the comparators. Its propensity to induce hypoglycemia is similar to or a little less than that of sulphonylureas. Repaglinide is associated with less weight gain than sulphonylureas and the glitazones. Repaglinide has primarily a role in the treatment of T2DM when metformin cannot be used due to adverse effects, when metformin fails to adequately control blood glucose levels, when there is a need for flexible dosing (i.e. the elderly or during Ramadan fasting), or when there is a specific wish to lower postprandial glucose. Repaglinide may also have an advantage when an oral agent is needed in diabetic patients with renal impairment. Because of its short duration of action, repaglinide should be taken before each meal, usually at least three times a day. Although no study has investigated whether repaglinide lowers total mortality or cardiovascular endpoints, several studies indicate beneficial effects on cardiovascular surrogate endpoints, such as carotid intima-media thickening, markers of inflammation, platelet activation, lipid parameters, endothelial function, adiponectin, and oxidative stress. In conclusion, repaglinide is a compound that can be used in both mono- and combination therapy for the treatment of both fasting and postprandial hyperglycemia in patients with T2DM. It can be used in patients at different stages of the disease, from uncomplicated to severe renal impairment. Although the drug has been tested in a large number of clinical trials and observational studies, its world-wide use is far less than, for example, sulphonylureas. Repaglinide may offer an additional potential for lowering blood glucose levels in T2DM that until now has not been fully realized by many clinicians.

Use of an electronic medical record to detect patients at high risk of metformin-induced lactic acidosis

The Notes section welcomes the following types of contributions: (1) practical innovations or solutions to everyday practice problems, (2) substantial updates or elaborations on work previously published by the same authors, (3) important confirmations of research findings previously published by others, and (4) short research reports, including practice surveys, of modest scope or interest. Notes should be submitted with AJHP's manuscript checklist. The text should be concise, and the number of references, tables, and figures should be limited.

Metformin-associated lactic acidosis treated with continuous renal replacement therapy

INTRODUCTION

Lactic acidosis is an infrequent complication of metformin therapy for diabetes mellitus. The presence of clinical conditions, such as renal failure, increases the risk of metformin-associated lactic acidosis (MALA). We present a case of lactic acidosis in a patient with diabetes treated with metformin, complicated by acute renal failure in preexisting chronic nephropathy.

CASE SUMMARY

A 70-year-old white male, weighing 77 kg, with diabetes mellitus, coronary heart disease, congestive heart failure (New York Heart Association class III), moderate essential hypertension (stage 2), and renal dysfunction (serum urea, 90 mg/dL; serum creatinine, 1.5 mg/dL; creatinine clearance, 49.8 mL/min/1.73 m2) presented to the emergency department of the General Hospital of Rhodes (Rhodes, Greece), complaining of malaise, respiratory distress, myalgias, disorientation, abdominal discomfort, and increasing somnolence of insidious onset. The patient's regimen included isosorbide mononitrate 60 mg QD, furosemide 40 mg QD, quinapril 20 mg QD, and metformin 850 mg TID. Before this hospitalization, he had received a 2-week course of oral diclofenac sodium 25 mg TID for low back pain. Preliminary laboratory evaluation found leukocytosis (27,300/mm3), severe renal failure (serum urea, 215 mg/dL; serum creatinine, 7.4 mg/dL; calculated creatinine clearance, 10.1 mL/min/1.73 m2), and a high anion gap metabolic acidosis (pH, 6.95; anion gap, 33 mEq/L) in arterial blood gas analysis. His medical and drug history, the clinical and laboratory findings, and the determination of lactate in samples of plasma (7.8 mEq/L), aroused the suspicion of MALA. The Naranjo algorithm scores for metformin and diclofenac sodium were 6 and 7, respectively. The patient received a single session of bicarbonate-buffered continuous venovenous hemodiafiltration (CWHDF) that lasted 16 hours. Ultimately, he was stabilized, and progressive restoration of acid-base balance and renal function was observed.

DISCUSSION

We suspect that lactic acidosis may have been related to the use of metformin, the presence of heart and renal failure (contributing to metformin toxicity), and previous use of diclofenac sodium. CVVHDF has an advantage over conventional intermittent hemodialysis in that it corrects acidosis and removes lactate and metformin without risk of hypernatremia or fluid overload.

CONCLUSIONS

MALA should be strongly suspected in diabetic patients presenting with high anion gap metabolic acidosis and increased serum lactate level. In the case described, prompt recognition of lactic acidosis and early application of bicarbonate-buffered CVVHDF produced successful results.