From the Guidelines
Beta-blockers are the primary medications for congestive heart failure (CHF) that can cause hypoglycemia, particularly non-selective beta-blockers like propranolol, nadolol, and carvedilol, which pose the highest risk. These medications can mask the warning signs of hypoglycemia, such as tremors, palpitations, and anxiety, making it particularly dangerous for diabetic patients. According to the standards of care in diabetes-2025, when initiating a new glucose-lowering medication, it is essential to reassess the need for and/or dose of medications with higher hypoglycemia risk, such as sulfonylureas, meglitinides, and insulin, to minimize the risk of hypoglycemia and treatment burden 1. Beta-blockers cause hypoglycemia by blocking the body's compensatory responses to low blood sugar, inhibiting glycogenolysis and gluconeogenesis in the liver, and impairing peripheral glucose uptake.
- Key points to consider:
- Diabetic patients on beta-blockers should monitor their blood glucose levels more frequently, especially when starting therapy or adjusting doses.
- They should also be educated about hypoglycemia symptoms that may still be recognizable despite beta-blocker therapy, such as confusion, hunger, and sweating.
- For diabetic CHF patients, cardioselective beta-blockers are generally preferred when possible to minimize this risk.
- The risk of hypoglycemia associated with beta-blockers should be weighed against their benefits in managing CHF, and alternative treatments should be considered if necessary.
From the FDA Drug Label
5.3 Hypoglycemia with Concomitant Use with Insulin and Insulin Secretagogues 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. Therefore, a lower dose of insulin or insulin secretagogue may be required to minimize the risk of hypoglycemia when used in combination with metformin hydrochloride tablet [see Drug Interactions ( 7)].
- Metformin can cause hypoglycemia when used in combination with insulin and/or an insulin secretagogue in patients with CHF.
- The risk of hypoglycemia may be increased when metformin is used with other medications that can cause hypoglycemia, such as insulin secretagogues.
- To minimize the risk of hypoglycemia, a lower dose of insulin or insulin secretagogue may be required when used in combination with metformin 2.
- Carvedilol may mask some of the manifestations of hypoglycemia, particularly tachycardia, in patients with type 2 diabetes 3.
From the Research
Medications for CHF that can cause Hypoglycemia
- Beta-blockers, particularly non-selective ones like propranolol, can cause metabolic disturbances, including hypoglycemia, especially when combined with insulin or in patients with diabetes 4.
- Metformin, often used in patients with diabetes, can cause hypoglycemia, even in the absence of other antidiabetic drugs, through mechanisms such as decreased hepatic glucose production and decreased glucose absorption 5.
- Patients with chronic heart failure are at risk of developing hypoglycemia, even without antidiabetic therapy, possibly due to malabsorption 6.
- Certain oral hypoglycemic medications, like sulfonylureas and meglitinides, can cause hypoglycemia, especially in older patients, alcoholics, and those with liver or renal disease 7.
- Metformin may have beneficial effects on heart failure-related outcomes, such as improving myocardial oxygen consumption and reducing markers of heart failure, but its impact on hypoglycemia in CHF patients is not fully understood 8.