Calcium channel blocker overdose typically presents with which effect on blood sugar?

• A. Hyperglycemia
• B. Hypoglycemia
• C. Normoglycemia
• D. Hyperglycemia

Answer: (D)

Calcium channels on pancreatic beta cells are what trigger insulin release when blood glucose rises. In an overdose, blocking those channels limits calcium entry into the beta cells, which blunts or stops insulin secretion. With less insulin available, glucose isn’t taken up as effectively by muscle and fat, and the liver isn’t as strongly suppressed in glucose production, so blood sugar levels rise. In this situation you’d expect hyperglycemia to be the typical finding, whereas hypoglycemia is not the usual result. Stress from the overdose can add to elevated glucose, but the primary mechanism is reduced insulin release due to calcium channel blockade.