What adjustment should be made to an 84-year-old patient's metformin (metformin hydrochloride) regimen, currently 1000 mg twice a day, given a fasting blood glucose level of 123 mg/dL, indicating impaired fasting glucose?

From the Guidelines

No adjustment to the metformin regimen is necessary at this time, as the patient's fasting blood sugar of 123 mg/dL is within an acceptable range for an elderly patient, and increasing the dose may increase the risk of side effects without substantial benefit. For patients over 80 years old, less stringent glycemic goals are often appropriate, with target fasting glucose typically between 100-140 mg/dL 1. The current dose of metformin 1000 mg twice daily is already at the maximum recommended daily dose. In elderly patients, we must balance glycemic control with safety concerns, particularly avoiding hypoglycemia which carries significant risks in this age group. According to the most recent guidelines, clinicians should aim to achieve an HbA1c level between 7% and 8% in most patients with type 2 diabetes, and consider deintensifying pharmacologic therapy in patients who achieve HbA1c levels less than 6.5% 1. Additionally, for patients with a life expectancy less than 10 years due to advanced age, residence in a nursing home, or chronic conditions, the harms of more intensive HbA1c targets outweigh the benefits, and the focus should be on minimizing symptoms related to hyperglycemia rather than achieving a specific HbA1c target 1. Therefore, continue monitoring the patient's blood glucose and A1C levels, and assess for any side effects of metformin such as gastrointestinal distress or vitamin B12 deficiency. If the patient's overall glycemic control worsens significantly, consider adding a second agent rather than increasing the metformin dose, taking into account the patient's individual characteristics, preferences, and comorbidities, as recommended by the American College of Physicians guidance statement 1.

From the FDA Drug Label

The recommended starting dose of metformin hydrochloride tablets are 500 mg orally twice a day or 850 mg once a day, given with meals. Increase the dose in increments of 500 mg weekly or 850 mg every 2 weeks on the basis of glycemic control and tolerability, up to a maximum dose of 2550 mg per day, given in divided doses.

The patient is currently taking metformin 1000 mg twice a day, which is within the recommended dosage range. Since the patient's fasting blood sugar is 123, which is not excessively high, and there is no information about the patient's previous blood sugar levels or how long they have been taking metformin, it is difficult to determine if an adjustment is needed.

• The patient's current dose is 2000 mg per day, which is below the maximum recommended dose of 2550 mg per day.
• However, without more information about the patient's renal function, it is not possible to make a recommendation about adjusting the dose.
• Given the patient's age and the potential for renal impairment, it is important to assess renal function before making any changes to the medication regimen 2. No conclusion can be drawn about adjusting the dose without more information.

From the Research

Patient's Current Condition

The patient is an 84-year-old with hyperglycemia, currently prescribed metformin 1000 mg twice a day, and has a fasting blood sugar level of 123.

Adjustment of Metformin Dosage

• The study 3 suggests that increasing the metformin dose can be effective in improving glycemic control in patients with type 2 diabetes who were initially prescribed low-dose metformin.
• However, the patient is already taking a relatively high dose of metformin (1000 mg twice a day), so further increases in dosage may not be necessary or advisable.

Alternative Treatment Options

• The study 4 compares the efficacy and safety of sulfonylureas and dipeptidyl peptidase-4 (DPP-4) inhibitors as second-line therapies in type 2 diabetes mellitus.
• The study 5 found that DPP-4 inhibitors produced a non-significant difference in HbA1c% change compared to sulfonylureas, but had a significant decrease in the rate of hypoglycemic events.
• The study 6 suggests that combination therapy with a DPP-4 inhibitor, metformin, and sulfonylurea can markedly improve HbA1c levels in patients with type 2 diabetes mellitus.

Considerations for Treatment Adjustment

• The patient's current fasting blood sugar level is 123, which is relatively well-controlled.
• However, if the patient's glycemic control is not satisfactory, alternative treatment options such as adding a DPP-4 inhibitor or sulfonylurea to the patient's current metformin regimen could be considered.
• The study 7 found that patients in the DPP-4 inhibitor cohort had slightly better adherence and persistence compared to the sulfonylurea cohort.