Drug-Food Interactions with Insulin and Insulin Glargine
The primary drug-food interaction with insulin (including insulin glargine) is the need for carbohydrate supplementation during and after exercise to prevent hypoglycemia, particularly with high-intensity or prolonged physical activity. 1
Exercise-Related Carbohydrate Requirements
Users of insulin and insulin secretagogues should supplement with carbohydrate as needed to prevent hypoglycemia during and after exercise. 1
High-intensity exercise (repeated interval or intense resistance training) can substantially deplete muscle glycogen, increasing the risk of postexercise hypoglycemia in insulin users. 1
Consumption of 5-30 grams of carbohydrate during and within 30 minutes after exhaustive, glycogen-depleting exercise will lower hypoglycemia risk and allow for more efficient restoration of muscle glycogen. 1
Persons with type 2 diabetes not using insulin or insulin secretagogues are unlikely to experience hypoglycemia related to physical activity. 1
Insulin Dose Adjustments Around Exercise
Before planned exercise, short-acting insulin doses will likely need to be reduced to prevent hypoglycemia, while longer-acting insulins such as glargine are less likely to cause exercise-induced hypoglycemia. 1
If only longer-acting insulins such as glargine, detemir, and NPH are being absorbed from subcutaneous depots during physical activity, exercise-induced hypoglycemia is not as likely, although doses may need to be reduced to accommodate regular participation in physical activity. 1
Rapid-acting insulin analogs (lispro, aspart, and glulisine) induce more rapid decreases in blood glucose than regular human insulin, requiring careful timing around exercise. 1
Individuals must monitor blood glucose levels before, occasionally during, and after exercise and compensate with appropriate dietary and/or medication regimen changes, particularly when exercising at insulin peak times. 1
Critical Mixing and Compatibility Considerations
Insulin glargine should not be mixed with other forms of insulin due to the low pH of its diluent, which represents a critical drug-drug interaction rather than a food interaction. 1
- No other medication or diluent should be mixed with any insulin product unless approved by the prescribing physician. 1
Storage and Food-Related Practical Considerations
Insulin in use may be kept at room temperature to limit local irritation at the injection site, which may occur when cold insulin is used. 1
Extreme temperatures (<36°F or >86°F, <2°C or >30°C) and excess agitation should be avoided to prevent loss of potency, clumping, frosting, or precipitation. 1
Common Pitfalls to Avoid
Do not assume that all insulin types have the same food interaction profile—glargine's peakless 24-hour action makes it less susceptible to exercise-induced hypoglycemia compared to short-acting insulins. 1
Failing to supplement with carbohydrates during high-intensity exercise in insulin users can lead to severe hypoglycemia, even with basal insulin like glargine if combined with prandial insulin. 1
Beta-blockers may block adrenergic symptoms of hypoglycemia, increasing the risk of undetected hypoglycemia during exercise in patients on insulin. 1