What is the most common adverse effect of insulin (intramuscular/intravenous hormone replacement) therapy?

From the Guidelines

Hypoglycemia is the most common adverse effect of insulin therapy, as evidenced by recent studies 1. This occurs when blood glucose levels drop too low, typically below 70 mg/dL, due to excess insulin in the body relative to carbohydrate intake or energy expenditure. Symptoms of hypoglycemia include:

• Shakiness
• Sweating
• Confusion
• Irritability
• Dizziness
• Hunger
• In severe cases, loss of consciousness or seizures Patients using insulin should always carry fast-acting carbohydrates such as glucose tablets, juice, or hard candies to treat hypoglycemia promptly. The risk of hypoglycemia is higher with intensive insulin regimens, during exercise, with alcohol consumption, or when meals are delayed or skipped. Physiologically, insulin lowers blood glucose by facilitating glucose uptake into cells and inhibiting glucose production by the liver. When insulin levels are too high relative to blood glucose, this mechanism can drive glucose levels dangerously low. Patients on insulin therapy should be educated about recognizing, preventing, and treating hypoglycemia as part of their diabetes management plan, as recommended by recent guidelines 1. A hypoglycemia management surveillance protocol should be adopted by all health systems, and treatment plans should be reviewed and changed as necessary to prevent hypoglycemia and recurrent hypoglycemia when a blood glucose value of <70 mg/dL is documented 1. Additionally, glucagon should be prescribed for all individuals requiring intensive insulin therapy or at high risk for hypoglycemia, and family, caregivers, school personnel, and others providing support to these individuals should know its location and be educated on how to administer it 1.

From the FDA Drug Label

Hypoglycemia: Most common adverse reaction of insulin therapy and may be life-threatening. Adverse events commonly associated with human insulin therapy include the following: ... Hypoglycemia

The most common adverse effect of insulin therapy is hypoglycemia. This is a life-threatening condition that requires close monitoring of blood glucose levels in patients treated with insulin 2, 3.

From the Research

Adverse Effects of Insulin Therapy

• The most common adverse effect of insulin therapy is hypoglycemia, as stated in multiple studies 4, 5, 6, 7.
• Hypoglycemia is a potential source of considerable morbidity and has a recognized mortality 5.
• Severe hypoglycemia is associated with significant morbidity, including reversible and permanent abnormalities of cardiovascular, neurological, and cognitive function 5, 6.
• The annual prevalence of severe hypoglycemia is around 30% in people with type 1 diabetes, and is higher in those with risk factors such as strict glycaemic control, impaired awareness of hypoglycaemia, and increasing duration of diabetes 6.

Prevalence and Risk Factors

• Mild, asymptomatic episodes of hypoglycemia occur once or twice a week in insulin-treated diabetic subjects 7.
• Asymptomatic hypoglycemia, including nocturnal hypoglycemia, occurs in about 25% of diabetic subjects treated with insulin therapy 7.
• Recurrent mild hypoglycemia can induce unawareness of hypoglycemia and impair glucose counterregulation, which in turn predisposes to severe hypoglycemia 7.

Minimizing the Risk of Hypoglycemia

• Frequent monitoring of blood sugars with home blood glucose tests and sometimes continuous glucose monitoring (CGM) can help identify hypoglycemia, particularly in hypoglycemia unawareness 4.
• Prompt measured hypoglycemia treatment, attempts to reduce glycemic variability, balancing basal and meal insulin therapy, and a pattern therapy approach can help minimize the risk of hypoglycemia 4.
• Using a physiological mimicry with insulin analogues in a flexible manner can also help reduce the risk of hypoglycemia 4, 7.