Humulin S (Soluble) (Insulin Human)

Humulin S is indicated for the management of blood glucose in adults and children with diabetes mellitus.

• Initiation and maintenance therapy for type 1 diabetes mellitus.
• Supplemental insulin for type 2 diabetes mellitus when oral agents are insufficient.
• Intravenous administration in hospital settings for rapid correction of hyperglycaemia or diabetic ketoacidosis.
• Subcutaneous dosing for basal‑bolus regimens in combination with longer‑acting insulin analogues.
• Peri‑operative glucose control in patients undergoing surgery.
• Adjustment of dose during illness or stress to prevent hyperglycaemia.

• Humulin S contains recombinant human insulin that binds to insulin receptors on the surface of muscle, adipose and hepatic cells. Receptor activation triggers autophosphorylation of the β‑subunit, initiating intracellular signaling cascades that promote translocation of GLUT‑4 transporters to the plasma membrane and stimulate glycogen synthesis while inhibiting gluconeogenesis. The net effect is increased cellular uptake of glucose and reduced blood glucose concentrations.

Adverse reactions to Humulin S may vary in frequency and severity.

Common

• Hypoglycaemia, presenting as sweating, tremor, confusion or loss of consciousness.
• Local injection‑site reactions such as redness, swelling, or itching.
• Weight gain associated with improved glycaemic control.
• Mild gastrointestinal discomfort such as nausea or abdominal pain.
• Transient visual disturbances, especially during rapid glucose changes.
• Skin lipohypertrophy at repeated injection sites.

Serious

• Severe hypoglycaemia requiring assistance from another person.
• Anaphylactic or systemic allergic reactions, including rash, urticaria, or airway swelling.
• Persistent hypokalemia or electrolyte disturbances secondary to high insulin levels.
• Insulin‑induced oedema that may exacerbate congestive heart failure.
• Severe hypoglycaemic coma requiring emergency medical intervention.
• Additional serious allergic reactions such as angioedema.

When prescribing or using Humulin S, several precautions should be considered to minimise risk and ensure safe therapy.

• Monitor blood glucose frequently, especially when initiating or changing dose.
• Adjust dose in renal or hepatic impairment.
• Use caution in patients with cardiovascular disease or heart failure due to risk of fluid retention.
• Educate patients on recognizing and treating hypoglycaemia.
• Avoid use in patients with known hypersensitivity to human insulin or excipients.
• Consider pregnancy and lactation status; insulin may be required but benefits outweigh risks.

Humulin S can 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.
• Beta‑blockers that mask hypoglycaemia symptoms.
• MAO‑inhibitors may potentiate insulin effect.
• Combination with meglitinides without dose reduction can cause severe hypoglycaemia.
• High‑dose glucocorticoids may necessitate substantial insulin dose increases.

Use with caution

• Oral antidiabetic agents (e.g., sulfonylureas, meglitinides) may increase hypoglycaemia risk.
• Corticosteroids can raise blood glucose, requiring higher insulin doses.
• Thyroid hormones may enhance insulin clearance.
• Alcohol consumption can cause delayed hypoglycaemia.
• Loop diuretics may alter potassium levels, influencing insulin activity.