Humulin R (Regolare) (Insulin Human)

Humulin R is indicated for the management of hyperglycemia in patients with diabetes mellitus.

• For adults and children with type 1 diabetes mellitus requiring basal‑bolus insulin regimens.
• For adults with type 2 diabetes mellitus when diet, exercise, and oral agents do not achieve glycemic targets.
• As short‑acting insulin in inpatient settings for rapid control of blood glucose during surgery or acute illness.
• In combination with intermediate‑ or long‑acting insulin preparations to provide comprehensive glucose coverage.
• For use in insulin pump therapy where a rapid‑acting formulation is required.
• Occasionally prescribed during pregnancy or lactation when other options are unsuitable and the clinician determines benefit.

• Humulin R contains recombinant human insulin that binds to insulin receptors on the surface of muscle, adipose and hepatic cells. Receptor activation triggers autophosphorylation and initiates intracellular signaling cascades, primarily the phosphatidylinositol‑3‑kinase (PI3‑K)/Akt pathway, which promotes translocation of GLUT‑4 transporters to the plasma membrane, increasing glucose uptake. In the liver, insulin suppresses gluconeogenesis and glycogenolysis, reducing effectively endogenous glucose production.

Adverse reactions to Humulin R may vary in frequency and severity, and they should be monitored during therapy.

Common

• Hypoglycemia, which may present as sweating, tremor, hunger, confusion, or visual disturbances, and may interfere with daily activities.
• Localized pain, redness, swelling, or itching at the injection site, often transient.
• Lipodystrophy, including lipoatrophy or lipohypertrophy, occurring with repeated injections in the same area.

Serious

• Severe hypoglycemia leading to loss of consciousness, seizures, or coma, requiring immediate treatment.
• Anaphylactic or systemic allergic reactions, such as angioedema, bronchospasm, or urticaria, which can be life‑threatening.
• Significant hypokalemia, particularly when insulin is given intravenously in high doses.

When prescribing or using Humulin R, clinicians and patients should consider several precautions to minimize risks.

• Adjust dose during illness, stress, or changes in diet/exercise.
• Monitor blood glucose frequently, especially when initiating therapy or changing dose.
• Use caution in patients with renal or hepatic impairment, as insulin clearance may be reduced.
• Assess for hypoglycemia unawareness and educate patients on recognizing symptoms.
• Avoid use in patients with known hypersensitivity to human insulin or any excipients.
• Consider cardiovascular status; rapid glucose shifts can affect heart disease patients.
• Pregnant or nursing women should be managed by a specialist; benefits must outweigh potential risks.

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

Avoid

• Concurrent use of other rapid‑acting insulins without dose adjustment.
• Co‑administration with sulfonylureas in patients prone to severe hypoglycemia.
• Concurrent use with meglitinides may increase risk of hypoglycemia.

Use with caution

• Oral antidiabetic agents (e.g., metformin, thiazolidinediones) may potentiate insulin effect.
• Corticosteroids, thiazide diuretics, and growth hormone can increase insulin requirements.
• Beta‑adrenergic antagonists may blunt hypoglycemia warning signs.
• Contrast media used in imaging may cause transient hyperglycemia.
• Alcohol consumption can enhance insulin’s glucose‑lowering effect and precipitate hypoglycemia.