Humulin R (Insulin Human (Rdna))

Humulin R is indicated for the management of hyperglycemia in adults and children with diabetes.

• Initiation of insulin therapy in type 1 diabetes mellitus.
• Supplemental (prandial) insulin for type 2 diabetes mellitus when diet, exercise, and oral agents are insufficient.
• Adjustment of basal‑bolus regimens to match carbohydrate intake.
• Management of gestational diabetes when rapid‑acting insulin is required.
• Use in inpatient settings for tight glucose control during surgery or acute illness.
• Transition from intravenous insulin infusion to subcutaneous Humulin R in critical care environments.

• Humulin R provides recombinant human insulin that binds to insulin receptors on muscle, adipose and hepatic cells. Receptor activation triggers autophosphorylation and downstream signaling through the PI3‑K/Akt pathway, promoting translocation of GLUT‑4 transporters to the cell membrane and increasing glucose uptake. In the liver, insulin suppresses gluconeogenesis and glycogenolysis, thereby lowering circulating glucose concentrations. The rapid onset of action allows it to cover the post‑prandial glucose rise.

Like all insulin preparations, Humulin R may be associated with adverse reactions that vary in frequency and severity, occasionally.

Common

• Hypoglycemia, presenting as sweating, tremor, or confusion.
• Injection site reactions such as redness, swelling, or itching.
• Lipodystrophy, including localized lipoatrophy or lipohypertrophy.
• Weight gain due to improved glycemic control.
• Transient visual disturbances such as blurred vision.
• Nausea or abdominal discomfort.
• Mild headache or dizziness.

Serious

• Severe hypoglycemia leading to loss of consciousness or seizures.
• Allergic reactions ranging from urticaria to anaphylaxis.
• Edema or heart failure exacerbation in susceptible patients.
• Hypersensitivity leading to serum sickness-like reaction.
• Persistent hyperglycemia indicating insulin resistance or dosing error.

When using Humulin R, clinicians and patients should observe several precautions to minimize risks and ensure effective therapy.

• Verify blood glucose before each injection to avoid hypoglycemia.
• Adjust dose during illness, pregnancy, or changes in physical activity.
• Rotate injection sites to prevent lipodystrophy.
• Store the product refrigerated; do not use if solution is cloudy or contains particles.
• Avoid mixing with other insulin types unless specifically instructed.
• Monitor for signs of allergic reaction, especially after the first few doses.
• Use caution in patients with renal or hepatic impairment.

Humulin R can interact with other medicines, affecting glucose control or increasing the risk of adverse events.

Avoid

• Concurrent use of high‑dose sulfonylureas may cause severe hypoglycemia.
• Beta‑blockers may mask hypoglycemia symptoms.
• Concurrent use of glucocorticoids can raise glucose levels, requiring dose adjustment.
• Meglitinides may potentiate insulin effect, increasing hypoglycemia risk.
• Exogenous insulin combined with insulin‑like growth factor‑1 can cause prolonged hypoglycemia.

Use with caution

• Thiazide diuretics may increase insulin resistance.
• ACE inhibitors may enhance insulin sensitivity.
• Alcohol can cause unpredictable glucose fluctuations.
• Non‑steroidal anti‑inflammatory drugs (NSAIDs) may affect renal function, altering insulin clearance.
• Thyroid hormone replacement may increase insulin requirements.