Humulin I (Isophane)

Humulin I (Isophane) is a recombinant human insulin (isophane) formulated for subcutaneous injection. It is supplied in multiple vial or cartridge strengths as an intermediate‑acting insulin solution. As a prescription‑only product marketed in the European Union, Humulin I provides basal insulin coverage for patients with diabetes. The preparation contains insulin human (rDNA) and is intended for use under a healthcare professional's guidance and should be administered according to a healthcare professional's guidance.

Humulin I (Isophane) is indicated for the management of hyperglycemia in adults and children with diabetes.

- Basal insulin therapy for type 1 diabetes mellitus. - Supplemental basal coverage in type 2 diabetes mellitus when diet, exercise, and oral agents are insufficient. - Combination with rapid‑acting insulin analogues to provide a basal‑bolus regimen. - Use in insulin‑pump therapy only when specifically prescribed (off‑label in some regions).

Adverse reactions to Humulin I (Isophane) may vary in frequency and severity.

Common: - Pain, redness, swelling, or bruising at the injection site, usually mild and transient. - Mild to moderate hypoglycemia, often occurring if a meal is missed, delayed, or carbohydrate intake is reduced. - Localized lipodystrophy, presenting as lipoatrophy or lipohypertrophy at repeated injection sites. - Gradual weight gain, typically modest and related to improved glycemic control. - Nausea, occasional abdominal discomfort, or a feeling of fullness after injection. - Headache, light‑headedness, or dizziness that resolves without intervention.

Serious: - Severe hypoglycemia with neuroglycopenic signs such as confusion, seizures, or loss of consciousness. - Allergic reactions ranging from urticaria and angioedema to full‑body anaphylaxis requiring emergency treatment. - Fluid retention, peripheral edema, or worsening of pre‑existing heart failure, especially in patients with cardiac disease. - Hypersensitivity responses that may manifest as serum‑sickness–like syndrome, including fever, rash, and arthralgia.

When prescribing or using Humulin I (Isophane), clinicians and patients should consider several safety precautions to minimize risk.

- Assess renal and hepatic function before initiating therapy and monitor periodically. - Adjust dose in patients with fluctuating dietary intake, physical activity, or concurrent illness. - Use caution in pregnant or breastfeeding women; benefits must outweigh potential risks. - Educate patients on recognizing and treating hypoglycemia promptly. - Avoid use in individuals with known hypersensitivity to human insulin or any excipients. - Monitor for signs of fluid retention or worsening heart failure, especially in cardiac patients. - Store the product according to label instructions and discard after the recommended in‑use period.

Humulin I (Isophane) may interact with other medications that affect glucose metabolism or insulin action.

Avoid: - Concurrent use of other rapid‑acting insulin preparations without dose adjustment, which can cause severe hypoglycemia. - Beta‑blockers that mask hypoglycemia symptoms and may prolong insulin’s glucose‑lowering effect.

Use with caution: - Oral antidiabetic agents (e.g., sulfonylureas, meglitinides) that increase the risk of additive hypoglycemia. - Corticosteroids, thiazide diuretics, or sympathomimetics that raise blood glucose and may require higher insulin doses. - Alcohol consumption, especially in excess, which can cause delayed hypoglycemia. - Anticoagulants such as heparin, which may alter insulin absorption at the injection site.