Humulin R, Novolin R, Regular Insulin, Velosulin, Velosulin BR, Velosulin Human
Classifications: hormone and synthetic substitute; antidiabetic agent; insulin
Pregnancy Category: B


100 units/mL


Short-acting, clear, colorless solution of exogenous unmodified insulin extracted from beta cells in pork pancreas or synthesized by recombinant DNA technology (human). Enhances transmembrane passage of glucose across cell membranes of most body cells and by unknown mechanism may itself enter the cell to activate selected intermediary metabolic processes. Promotes conversion of glucose to glycogen.

Therapeutic Effects

It lowers blood glucose levels by increasing peripheral glucose uptake, especially by skeletal muscle and fat tissue, and by inhibiting the liver from changing glycogen to glucose.


Emergency treatment of diabetic ketoacidosis or coma, to initiate therapy in patient with insulin-dependent diabetes mellitus, and in combination with intermediate-acting or long-acting insulin to provide better control of blood glucose concentrations in the diabetic patient. Used IV to stimulate growth hormone secretion (glucose counter regulatory hormone) to evaluate pituitary growth hormone reserve in patient with known or suspected growth hormone deficiency. Other uses include promotion of intracellular shift of potassium in treatment of hyperkalemia (IV) and induction of hypoglycemic shock as therapy in psychiatry.


Hypersensitivity to insulin animal protein.

Cautious Use

Pregnancy (category B), lactation, renal impairment, hepatic impairment, and older adults. Safety and efficacy in children <2 y are not established.

Route & Dosage

Diabetes Mellitus
Adult: SC 5–10 U 15–30 min a.c. and h.s. (dose adjustments based on blood glucose determinations)
Child: SC 2–4 U 15–30 min a.c. and h.s. (dose adjustments based on blood glucose determinations)

Adult: IV 2.4–7.2 U loading dose, followed by 2.4–7.2 U/h continuous infusion
Child: IV 0.1 U/kg loading dose, followed by 0.1 U/h continuous infusion


Note: Insulins should not be mixed unless prescribed by physician. In general, regular insulin is drawn up into syringe first. Any change in the strength (e.g., U-40, U-100), brand (manufacturer), purity, type (regular, etc.), species (pork, human), or sequence of mixing two kids of insulin is made by the physician only, since a simultaneous change in dosage may be necessary.


PREPARE: Direct: Give undiluted.  Continuous: Typically diluted in NS or 0.45% NaCl. 100 U added to 1000 mL yields 0.1 U/mL.  

ADMINISTER: Direct: Give 50 U or a fraction thereof over 1 min.  Continuous: Rate must be ordered by physician.  

INCOMPATIBILITIES Solution/additive: Aminophylline, amobarbital, chlorothiazide, cytarabine, dobutamine, pentobarbital, phenobarbital, phenytoin, secobarbital, sodium bicarbonate, thiopental. Y-site: Dobutamine.

  • Regular insulin may be adsorbed into the container or tubing when added to an IV infusion solution. Amount lost is variable and depends on concentration of insulin, infusion system, contact duration, and flow rate.
  • Monitor patient response closely.

Adverse Effects (1%)

Body as a Whole: Most adverse effects are related to hypoglycemia; anaphylaxis (rare), hyperinsulinemia [Profuse sweating, hunger, headache, nausea, tremulousness, tremors, palpitation, tachycardia, weakness, fatigue, nystagmus, circumoral pallor; numb mouth, tongue, and other paresthesias; visual disturbances (diplopia, blurred vision, mydriasis), staring expression, confusion, personality changes, ataxia, incoherent speech, apprehension, irritability, inability to concentrate, personality changes, uncontrolled yawning, loss of consciousness, delirium, hypothermia, convulsions, Babinski reflex, coma. (Urine glucose tests will be negatives). CNS: With overdose, psychic disturbances (i.e., aphasia, personality changes, maniacal behavior). Metabolic: Posthypoglycemia or rebound hyperglycemia (Somogyi effect), lipoatrophy and lipohypertrophy of injection sites; insulin resistance. Skin: Localized allergic reactions at injection site; generalized urticaria or bullae, lymphadenopathy.

Diagnostic Test Interference

Large doses of insulin may increase urinary excretion of VMA. Insulin can cause alterations in thyroid function tests and liver function test and may decrease serum potassium and serum calcium.


Drug: Alcohol, anabolic steroids, mao inhibitors, guanethidine, salicylates may potentiate hypoglycemic effects; dextrothyroxine, corticosteroids, epinephrine may antagonize hypoglycemic effects; furosemide, thiazide diuretics increase serum glucose levels; propranolol and other beta blockers may mask symptoms of hypoglycemic reaction. Herbal: Garlic, ginseng may potentiate hypoglycemic effects.


Absorption: Rapidly absorbed from IM and SC injections. Onset: 0.5–1 h. Peak: 2–3 h. Duration: 5–7 h. Distribution: Throughout extracellular fluids. Metabolism: Metabolized primarily in liver with some metabolism in kidneys. Elimination: <2% excreted in urine. Half-Life: Biological, up to 13 h.

Nursing Implications

Assessment & Drug Effects

Patient & Family Education

Common adverse effects in italic, life-threatening effects underlined; generic names in bold; classifications in SMALL CAPS; Canadian drug name; Prototype drug