Discontinue the metformin in this elderly hospice patient
In an elderly hospice patient with glucose values of 92-110 mg/dL on 500 mg metformin ER daily, you should discontinue the metformin entirely rather than dose it every other day. 1
Rationale for Discontinuation
Metformin Does Not Cause Hypoglycemia
Your concern about hypoglycemia, while understandable, is actually misplaced. Metformin does not cause hypoglycemia when used as monotherapy 1, 2. The drug works by enhancing insulin sensitivity and decreasing hepatic glucose output—it does not stimulate insulin secretion 3. The glucose values of 92-110 mg/dL are well within the recommended fasting goal of 90-150 mg/dL for older adults 1.
Why Discontinue in Hospice Care
The key issue here is not hypoglycemia risk, but rather the appropriateness of continuing diabetes treatment in a hospice patient:
Metformin can cause problematic side effects in elderly patients, including gastrointestinal intolerance and reduced appetite 1—both particularly concerning in hospice patients where maintaining nutrition and comfort are priorities
The glucose-lowering benefit is unnecessary when values are already well-controlled at 92-110 mg/dL, and aggressive glycemic control provides no mortality or quality-of-life benefit in end-of-life care
Metformin requires ongoing monitoring of renal function every 3-6 months 1, which is burdensome and inconsistent with hospice goals of care
Why Not Every-Other-Day Dosing?
Every-other-day dosing of metformin is not a standard or evidence-based approach. Metformin has a relatively short half-life and requires daily dosing for consistent effect 4. Intermittent dosing would create:
- Unpredictable glucose fluctuations
- No established safety or efficacy data
- Continued exposure to side effects without clear benefit
Common Pitfall to Avoid
The major pitfall here is conflating metformin with insulin secretagogues (sulfonylureas). Sulfonylureas like glyburide or glipizide DO cause hypoglycemia and should be avoided in older adults 1. Metformin does not share this risk profile. However, in the hospice context, the decision to discontinue is still correct—just for different reasons (quality of life, medication burden, lack of benefit) rather than hypoglycemia risk.
Practical Implementation
Simply stop the metformin. No taper is needed. Monitor glucose levels periodically (weekly is reasonable) to ensure they remain acceptable, but recognize that even values up to 200-250 mg/dL are often tolerated well in hospice patients and do not require treatment unless causing symptomatic hyperglycemia (polyuria, polydipsia, dehydration).