|EVIDENCE-BASED MEDICINE: SUMMARY OF STUDY
|Year : 2017 | Volume
| Issue : 3 | Page : 240-242
Use of metformin in chronic kidney disease, congestive heart failure, and chronic liver disease
|Date of Web Publication||7-Aug-2017|
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
. Use of metformin in chronic kidney disease, congestive heart failure, and chronic liver disease. Curr Med Issues 2017;15:240-2
Source: This is a summary of the study: Clinical Outcomes of Metformin Use in Populations with Chronic Kidney Disease, Congestive Heart Failure, or Chronic Liver Disease: A Systematic Review. Authors: Crowley MJ, Diamantidis CJ, McDuffie JR, Cameron CB, Stanifer JW, Mock CK, et al. Ann Intern Med. 2017 Feb 7;166(3):191-200. doi: 10.7326/M16-1901. Summary prepared by Dr. Ajay Kumar Mishra, Christian Medical College, Vellore, Tamil Nadu, India.
Clinical Question: Is metformin safe for use in individuals with chronic kidney disease, congestive heart failure, or chronic liver disease?
Authors' conclusion: With appropriate dose optimization, the use of metformin in patients with type 2 diabetes mellitus and moderate chronic kidney disease, congestive heart failure, or chronic liver disease is associated with improvement in clinical outcomes.
Case Scenario: A 65-year retired school teacher comes to a general practitioner with her concern regarding her medications. She has well-controlled diabetes, hypertension, dyslipidemia, and chronic kidney disease (CKD). Recently, she had visited another health practitioner who had advised her to stop Glyciphage (metformin) stating that this drug is contraindicated in CKD. What should be the clinician's response?
| Background|| |
Metformin is the first-line therapy for type 2 diabetes  and is used widely. Traditionally, metformin is contraindicated in patients with chronic kidney disease (CKD), congestive heart failure (CHF), and chronic liver disease (CLD). However, most of the evidence regarding the same has been based on historical evidence of significant lactic acidosis by phenformin and under the presumption that decreased excretion (CKD) and increased accumulation (CHF and CLD) of lactate would precipitate lactic acidosis. This study aimed to review the clinical outcomes of metformin use in patients with CKD, CHF, and CLD.
| Results|| |
- The relative chance of death in patients with CKD (estimated glomerular filtration rate >30 mL/min/1.73 m 2) and congestive cardiac failure (left ventricular ejection fraction 30%–40%) was 22% lower for patients receiving metformin as compared to those not receiving it
- CHF patients on metformin had 13% lower readmission rate for CHF
- Reduce mortality was seen in patients on metformin for CLD as well (<10%)
- None of the studies evaluated the effect of metformin on glycemic control, lipid control, hypoglycemia, weight gain, or Vitamin B12 deficiency in adults with diabetes with contraindications of interest.
All studies were observational studies and most are retrospective; hence, the strength of evidence is suboptimal and risk of bias is significant.
| Conclusion|| |
In the above case scenario, the physician should estimate the patient's glomerular filtration rate and optimize her metformin dosing accordingly [Table 1].
|Table 1: Food and Drug Administration approvals/recommendations for metformin usage|
Click here to view
The systematic review has a robust methodology and includes a large number of patients with a well-defined outcome. The improvement in mortality in patients on metformin confirms that it can be safely be used in patients with CKD, CHF, and CLD. However, the clinician needs to be aware that these studies were observational (most being retrospective), did not have details of dosage of metformin, and excluded sicker patients. In a real clinical setting, the same patient may often have more than one comorbidity, i.e., CKD and congestive cardiac failure/CLD. None of the studies evaluated effect of metformin usage and the spectrum of complications in such a group of patients. Hence, the clinician should educate the patient regarding the expected adverse effect and advise meticulous follow-up of such patients while prescribing metformin.
Financial support and sponsorship
Conflicts of interets
There are no conflicts of interest.
| References|| |
Standards of medical care in diabetes-2017: Summary of revisions. Diabetes Care 2017;40 Suppl 1:S4-5.
Crowley MJ, Diamantidis CJ, McDuffie JR, Cameron CB, Stanifer JW, Mock CK, et al.
Clinical outcomes of metformin use in populations with chronic kidney disease, congestive heart failure, or chronic liver disease: A systematic review. Ann Intern Med 2017;166:191-200.