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Insulin (umbrella) Pregnancy: UK SPC §4.6, verbatim: 'There are no restrictions on treatment of diabetes with insulin during pregnancy, as insulin does not pass the placental barrier. Both hypoglycaemia and hyperglycaemia, which can occur in inadequately controlled diabetes therapy, increase the risk of malformations and death in utero. Intensified blood glucose control and monitoring of pregnant women with diabetes are recommended throughout pregnancy and when contemplating pregnancy. Insulin requirements usually fall in the first trimester and increase subsequently during the second and third trimesters. After delivery, insulin requirements normally return rapidly to pre-pregnancy values.' Breast-feeding: 'There is no restriction on treatment with Actrapid during breast-feeding. Insulin treatment of the nursing mother presents no risk to the baby. However, the Actrapid dose may need to be adjusted.' Fertility: 'Animal reproduction studies with human insulin have not revealed any adverse effects on fertility.'

Insulin (general)

Brand names: Actrapid, Humulin, Insulatard

Insulin is the principal glucose-lowering hormone, given as replacement therapy in type 1 diabetes and in type 2 diabetes or other hyperglycaemic states when other measures are insufficient.

Adult dose

Dose: Insulin replacement in diabetes mellitus — the individual insulin requirement is usually 0.3 to 1.0 international units/kg/DAY as a TOTAL DAILY requirement (not a per-injection dose). §4.2, verbatim: 'The potency of human insulin is expressed in international units. Actrapid dosing is individual and determined in accordance with the needs of the patient. It can be used alone or in combination with intermediate-acting or long-acting insulin before a meal or a snack. The individual insulin requirement is usually between 0.3 and 1.0 international unit/kg/day.' SCOPE: this figure is quoted from the SPC of ONE fast-acting soluble human insulin (Actrapid 100 international units/ml), one of this page's own brands. Rapid-acting, short-acting soluble, intermediate-acting, long-acting and premixed insulins differ in strength, timing and route and are NOT interchangeable — always prescribe by brand and preparation and take the actual dose from that product's own SPC.
Route: Subcutaneous injection into the abdominal wall, thigh, gluteal region or deltoid region, rotating sites within the same region. §4.2, verbatim: 'Injection sites should always be rotated within the same region in order to reduce the risk of lipodystrophy and cutaneous amyloidosis (see sections 4.4 and 4.8). Injection into a lifted skin fold minimises the risk of unintended intramuscular injection. The needle should be kept under the skin for at least 6 seconds to make sure the entire dose is injected. Subcutaneous injection into the abdominal wall ensures a faster absorption than other injection sites.' Intravenous use is possible for this product but is a healthcare-professional procedure — verbatim: 'If necessary, Actrapid can be administered intravenously. This should be carried out by healthcare professionals.' NOT for continuous subcutaneous pump infusion — verbatim: 'Due to the risk of precipitation in pump catheters, Actrapid should not be used in insulin pumps for continuous subcutaneous insulin infusion.'
Frequency: Individualised, given before a meal or a snack, alone or in combination with an intermediate- or long-acting insulin. §4.2, verbatim: 'An injection should be followed within 30 minutes by a meal or snack containing carbohydrates.' and 'Adjustment of dose may be necessary if patients undertake increased physical activity, change their usual diet or during concomitant illness.'
maxDose is blank because §4.2 states no ceiling of any kind — insulin is titrated against blood glucose. ⚠️ THE 0.3–1.0 INTERNATIONAL UNIT/KG FIGURE IS PER DAY. It is a total daily requirement, not a per-injection dose, and it is not an intravenous infusion rate — the sibling 'insulin_infusion' page needs a units/hour variable-rate protocol, which no SPC in this bundle provides. DURATION OF ACTION, §4.2 verbatim: 'The duration of action will vary according to the dose, injection site, blood flow, temperature and level of physical activity.' SPECIAL POPULATIONS, §4.2 verbatim: 'Elderly (≥ 65 years old) Actrapid can be used in elderly patients. In elderly patients, glucose monitoring should be intensified and the insulin dose adjusted on an individual basis.' and 'Renal and hepatic impairment Renal or hepatic impairment may reduce the patient's insulin requirements. In patients with renal or hepatic impairment, glucose monitoring should be intensified and the human insulin dose adjusted on an individual basis.' TRANSFER BETWEEN INSULINS, §4.2 verbatim: 'When transferring from other insulin medicinal products, adjustment of the Actrapid dose and the dose of the basal insulin may be necessary. Close glucose monitoring is recommended during the transfer and in the initial weeks thereafter.' §4.4 adds, verbatim: 'Transferring a patient to another type or brand of insulin should be done under strict medical supervision. Changes in strength, brand (manufacturer), type, origin (animal insulin, human insulin or insulin analogue) and/or method of manufacture (recombinant DNA versus animal source insulin) may result in a need for a change in dose. Patients transferred to Actrapid from another type of insulin may require an increased number of daily injections or a change in dose from that used with their usual insulin medicinal products. If an adjustment is needed, it may occur with the first dose or during the first few weeks or months.' INTRAVENOUS COMPATIBILITY (a stability statement, NOT a rate), §4.2 verbatim: 'For intravenous use, infusion systems with Actrapid at concentrations from 0.05 international unit/ml to 1.0 international unit/ml human insulin in the infusion fluids 0.9% sodium chloride, 5% dextrose and 10% dextrose with 40 mmol/l potassium chloride using polypropylene infusion bags, are stable at room temperature for 24 hours. Although stable over time, a certain amount of insulin will initially be adsorbed to the material of the infusion bag. Monitoring of blood glucose is necessary during the insulin infusion.' SYRINGE USE, §4.2 verbatim: 'Actrapid vials are for use with insulin syringes with a corresponding unit scale. When two types of insulin are mixed always mix the insulin medicinal products in the same sequence.' TRAVEL, §4.4: 'Before travelling between different time zones, the patient should seek the doctor's advice since this may mean that the patient has to take the insulin and meals at different times.' The US ADMELOG label supplies no numeric dose — it states only that dosage is 'individualized based on the route of administration and the patient's metabolic needs, blood glucose monitoring results, and glycemic control goal' — so nothing numeric is imported from it.

Paediatric dose

Route: Subcutaneous
Frequency: Individualised
dosePerKg is null because §4.2 gives NO separate paediatric figure. The entire paediatric statement is, verbatim: 'Paediatric population Actrapid can be used in children and adolescents.' The 0.3–1.0 international unit/kg/day requirement quoted in the adult entry appears once under Posology without an age qualifier and is a TOTAL DAILY requirement, not a per-dose figure, so it is deliberately not wired into the weight calculator here — feeding a daily total into a per-dose calculator would produce a several-fold overdose. Dose paediatric insulin from the specific preparation's own SPC, a children's formulary and paediatric diabetes specialist advice. The US ADMELOG label adds only that paediatric effectiveness 'is supported by evidence from an adequate and well-controlled study with another insulin lispro product, 100 units/ml, in 60 pediatric patients 3 years of age and older with type 1 diabetes mellitus' — again with no numeric dose, and for a different molecule.

Dose adjustments

Renal

§4.2, verbatim: 'Renal and hepatic impairment Renal or hepatic impairment may reduce the patient's insulin requirements. In patients with renal or hepatic impairment, glucose monitoring should be intensified and the human insulin dose adjusted on an individual basis.' No numeric dose reduction is stated. §4.4 adds that 'Concomitant diseases in the kidney, liver or affecting the adrenal, pituitary or thyroid gland can require changes in the insulin dose.'

Hepatic

Covered by the same §4.2 statement as renal impairment — hepatic impairment may reduce insulin requirements; intensify glucose monitoring and adjust the dose on an individual basis. No numeric adjustment is stated.

Dose independently re-sourced from UK Summary of Product Characteristics (SPC) via the eMC; US FDA prescribing information (openFDA / DailyMed) — cross-check; US labelling may differ from UK — clinician-reviewed. Always confirm against the product SmPC and your local formulary before prescribing.

Contraindications

  • [Actrapid UK SPC §4.3] 'Hypersensitivity to the active substance or to any of the excipients listed in section 6.1.'
  • [Actrapid UK SPC §4.4] Hypoglycaemia — 'In case of hypoglycaemia or if hypoglycaemia is suspected, Actrapid must not be injected. After stabilisation of the patient's blood glucose, adjustment of the dose should be considered.' The US ADMELOG label §4 states this as an outright contraindication: 'ADMELOG is contraindicated: during episodes of hypoglycemia.'
  • [Actrapid UK SPC §4.2 — a route bar rather than a formal contraindication] 'Due to the risk of precipitation in pump catheters, Actrapid should not be used in insulin pumps for continuous subcutaneous insulin infusion.'
  • [ADMELOG US label §4] 'in patients who are hypersensitive to insulin lispro or to any of the excipients in ADMELOG' — product-specific to that US insulin lispro presentation.

Side effects

  • [§4.8] Hypoglycaemia — very common, and the most frequently reported adverse reaction: 'Severe hypoglycaemia may lead to unconsciousness and/or convulsions and may result in temporary or permanent impairment of brain function or even death. The symptoms of hypoglycaemia usually occur suddenly. They may include cold sweats, cool pale skin, fatigue, nervousness or tremor, anxiousness, unusual tiredness or weakness, confusion, difficulty in concentrating, drowsiness, excessive hunger, vision changes, headache, nausea and palpitation.'
  • [§4.8] Urticaria and rash (uncommon); anaphylactic reactions (very rare) — 'The occurrence of generalised hypersensitivity reactions (including generalised skin rash, itching, sweating, gastrointestinal upset, angioneurotic oedema, difficulty in breathing, palpitation and reduction in blood pressure) is very rare but can potentially be life threatening.'
  • [§4.8] Peripheral (painful) neuropathy — uncommon: 'Fast improvement in blood glucose control may be associated with acute painful neuropathy, which is usually reversible.'
  • [§4.8] Refraction disorders (uncommon) and diabetic retinopathy (very rare) — 'Intensification of insulin therapy with abrupt improvement in glycaemic control may be associated with temporary worsening of diabetic retinopathy, while long-term improved glycaemic control decreases the risk of progression of diabetic retinopathy.'
  • [§4.8] Lipodystrophy (uncommon) and cutaneous amyloidosis (frequency not known) at injection sites — rotate injection sites within the same region.
  • [§4.8 / §4.4] Injection site reactions (uncommon) — 'pain, redness, hives, inflammation, bruising, swelling and itching'; usually resolve in a few days to a few weeks. Oedema (uncommon), typically at the start of treatment.
  • [§4.4] Hyperglycaemia and diabetic ketoacidosis from inadequate dosing or discontinuation — 'In type 1 diabetes, untreated hyperglycaemic events eventually lead to diabetic ketoacidosis, which is potentially lethal.'
  • This side-effect list may be incomplete — check the full SPC.

Interactions

  • [ADMELOG US label §7 — US labelling; verify against the UK SPC. No §4.5 was captured from the Actrapid SPC in this bundle.] Drugs that may increase the risk of hypoglycaemia: 'Antidiabetic agents, ACE inhibitors, angiotensin II receptor blocking agents, disopyramide, fibrates, fluoxetine, monoamine oxidase inhibitors, pentoxifylline, pramlintide, salicylates, somatostatin analogs (e.g., octreotide), and sulfonamide antibiotics.'
  • [ADMELOG US label §7] Drugs that may decrease the blood-glucose-lowering effect: 'Atypical antipsychotics (e.g., olanzapine and clozapine), corticosteroids, danazol, diuretics, estrogens, glucagon, isoniazid, niacin, oral contraceptives, phenothiazines, progestogens (e.g., in oral contraceptives), protease inhibitors, somatropin, sympathomimetic agents (e.g., albuterol, epinephrine, terbutaline), and thyroid hormones.'
  • [ADMELOG US label §7] Drugs that may increase or decrease the blood-glucose-lowering effect: 'Alcohol, beta-blockers, clonidine, and lithium salts. Pentamidine may cause hypoglycemia, which may sometimes be followed' [truncated at the source-fetch limit].
  • [ADMELOG US label §5.7] Thiazolidinediones with insulin — 'Fluid Retention and Heart Failure with Concomitant Use of Thiazolidinediones (TZDs): Observe for signs and symptoms of heart failure; consider dosage reduction or discontinuation if heart failure occurs.'

Monitoring

  • [§4.4] Warning symptoms of hypoglycaemia may change or disappear — 'Patients whose blood glucose control is greatly improved, e.g. by intensified insulin therapy, may experience a change in their usual warning symptoms of hypoglycaemia and should be advised accordingly. Usual warning symptoms may disappear in patients with longstanding diabetes.'
  • [§4.2] Intensify glucose monitoring and individualise the dose in patients aged 65 years and over and in renal or hepatic impairment.
  • [§4.2] Close glucose monitoring during and for the initial weeks after any transfer between insulin products, which must be done under strict medical supervision.
  • [§4.4] Concomitant illness — 'Concomitant illness, especially infections and feverish conditions, usually increases the patient's insulin requirement.'
  • [§4.2 / §4.8] Inspect and rotate injection sites within the same region at each review, to detect and reduce lipodystrophy and cutaneous amyloidosis.
  • [§4.2] Blood glucose during any intravenous insulin — 'Monitoring of blood glucose is necessary during the insulin infusion.'

Clinical monograph

How it works

It promotes cellular glucose uptake, suppresses hepatic glucose production and inhibits lipolysis and ketogenesis, lowering blood glucose.

Prescribing in practice

  • Hypoglycaemia is the major risk, and insulin is a recognised high-alert medicine for which prescribing units in words ('units', never 'U') and double-checking are essential to avoid serious dosing errors.
  • Never abruptly stop insulin in type 1 diabetes, as this precipitates diabetic ketoacidosis even during intercurrent illness.
  • Numerous formulations with different onset and duration exist; specify the exact preparation and device to avoid confusion.

Monitoring

Monitor capillary blood glucose, HbA1c and for hypoglycaemia, with ketone monitoring during illness in insulin-dependent patients.

Counselling the patient

  • Learn to recognise and treat hypoglycaemia and always carry fast-acting carbohydrate.
  • Rotate injection sites to prevent lipohypertrophy and never share pens or needles.
  • Follow sick-day rules and do not stop insulin if you are unwell or eating poorly.

Evidence & guidelines

Insulin is life-sustaining in type 1 diabetes, and intensive control is supported by landmark trials such as the DCCT.

Reference: NICE NG17/NG28; ABCD/JBDS guidance; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).

Related

Curated clinical cross-links plus same-class fallbacks.

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