As with other human insulin preparations, hypoglycemic reactions may be associated with the administration of Humulin R (U–500). However, deep secondary hypoglycemic reactions may develop 18 to 24 hours after the original injection of Humulin R (U–500). Consequently, patients should be carefully observed, and prompt treatment of such reactions should be initiated with glucagon injections and/or with glucose by intravenous injection or gavage.
Hypoglycemia is one of the most frequent adverse events experienced by insulin users.
Symptoms of mild to moderate hypoglycemia may occur suddenly and can include:
Signs of severe hypoglycemia can include:
Early warning symptoms of hypoglycemia may be different or less pronounced under certain conditions, such as long duration of diabetes, diabetic nerve disease, medications such as beta–blockers, change in insulin preparations, or intensified control (3 or more insulin injections per day) of diabetes.
A few patients who have experienced hypoglycemic reactions after transfer from animal–source insulin to human insulin have reported that the early warning symptoms of hypoglycemia were less pronounced or different from those experienced with their previous insulin.
Without recognition of early warning symptoms, the patient may not be able to take steps to avoid more serious hypoglycemia. Patients who experience hypoglycemia without early warning symptoms should monitor their blood glucose frequently, especially prior to activities such as driving. Mild to moderate hypoglycemia may be treated by eating foods or taking drinks that contain sugar. Patients should always carry a quick source of sugar, such as candy mints or glucose tablets.
Hypoglycemia when using Humulin R (U–500) can be prolonged and severe.
Rarely, administration of insulin subcutaneously can result in lipoatrophy (depression in the skin) or lipohypertrophy (enlargement or thickening of tissue).
Allergy to Insulin
Local Allergy — Patients occasionally experience erythema, local edema, and pruritus at the site of injection of insulin. This condition usually is self–limiting. In some instances, this condition may be related to factors other than insulin, such as irritants in the skin cleansing agent or poor injection technique.
Systemic Allergy — Less common, but potentially more serious, is generalized allergy to insulin, which may cause rash over the whole body, shortness of breath, wheezing, reduction in blood pressure, fast pulse, or sweating. Severe cases of generalized allergy (anaphylaxis) may be life threatening.