Which of her medications should she be counseled to avoid increased levels of?

From the Guidelines

The patient should be counseled to avoid increased levels of Metformin, as it can lead to lactic acidosis, particularly in patients with impaired kidney function or those at risk for lactic acidosis 1.

Key Considerations

• Metformin should be avoided in patients with significant renal impairment, as it can increase the risk of lactic acidosis 1.
• The patient's kidney function should be closely monitored, and metformin should be discontinued if the estimated glomerular filtration rate (eGFR) is less than 30 mL/min per 1.73 m² 1.
• Lactate concentrations should be measured in fragile patients, and metformin should be withdrawn if increased lactate concentrations are apparent 1.

Medication Management

• The patient's current medication list should be reviewed, and any potential interactions with metformin should be identified and addressed.
• The patient should be advised to inform all healthcare providers about their complete medication list and to check with a pharmacist or physician before starting any new medications, including over-the-counter products and supplements, to avoid potentially dangerous drug interactions.

Additional Recommendations

• The patient's blood pressure, heart rate, and blood glucose levels should be closely monitored, and any changes in their condition should be promptly addressed.
• The patient should be educated on the importance of proper medication management and the potential risks associated with increased metformin levels.

Relevant Guidelines

• The patient's medication regimen should be guided by the most recent clinical practice guidelines, such as those published in The Lancet Diabetes and Endocrinology 1 and the American Journal of Kidney Diseases 1.

From the FDA Drug Label

The risk of metformin accumulation and metformin-associated lactic acidosis increases with the severity of renal impairment because metformin is substantially excreted by the kidney.

Certain individuals (those with inadequate vitamin B 12 or calcium intake or absorption) appear to be predisposed to developing subnormal vitamin B 12 levels.

Insulin and insulin secretagogues (e.g., sulfonylurea) are known to cause hypoglycemia. Metformin hydrochloride tablets may increase the risk of hypoglycemia when combined with insulin and/or an insulin secretagogue.

The patient should be counseled to avoid increased levels of Metformin.

• Key factors that may contribute to increased metformin levels include renal impairment, certain drug interactions, and age 65 or greater.
• Monitoring of renal function, hematologic parameters, and vitamin B12 levels is recommended for patients taking metformin.
• Dose adjustment may be necessary to minimize the risk of metformin-associated lactic acidosis or hypoglycemia 2.

From the Research

Medication Therapy Management

The patient, a 70-year-old female with a history of dyslipidemia, hypertension, stable ischemic heart disease, and type 2 diabetes mellitus, is taking multiple medications, including metformin.

Potential Risks

• Metformin is known to cause lactic acidosis, a rare but potentially fatal condition, especially in patients with kidney impairment or those at risk of acute kidney injury (AKI) 3, 4.
• The risk of lactic acidosis is substantially higher in patients with kidney impairment, and regulatory agencies have maintained strict renal restrictions surrounding metformin use 4.
• However, some studies suggest that metformin can be used safely in patients with stable chronic renal failure, with a significantly lower incidence of cardiovascular events and mortality compared to other hypoglycaemic agents 5.

Medication to Avoid Increased Levels

• Based on the patient's medical history and current medications, she should be counseled to avoid increased levels of Metformin (A), as it can cause lactic acidosis, especially in patients with kidney impairment or those at risk of AKI 3, 4.
• The other options, Metoprolol succinate (B), Procardia XL (C), Rosuvastatin (D), and Victoza (E), do not have the same level of risk associated with increased levels in this patient's context.

Key Considerations

• Patients receiving metformin should be counseled to stop metformin and seek medical care in the setting of illnesses, especially those that may affect kidney function 3.
• Metformin levels may help in diagnosis and management, but the means to identify metformin levels are not widely available 3.
• The patient's renal function and risk of AKI should be closely monitored, and metformin dose modification may be necessary to achieve a predicted plasma metformin < 10 mg/l 5.