Rapid-acting analogue insulin Pregnancy: Can be used during pregnancy; intensified blood-glucose control and monitoring recommended (insulin requirements usually fall in the first trimester and rise during the second and third). No restrictions during breast-feeding.

Insulin aspart

Brand names: NovoRapid, Fiasp

A rapid-acting insulin analogue used at mealtimes in diabetes, suitable for subcutaneous injection, insulin pumps, and intravenous use in acute care.

Auto-extracted from the source labelling — not yet independently clinician-verified. These values were distilled from the UK SPC (or the US label where noted) but have not had a clinician sign-off. Confirm against the current SmPC before prescribing.

Adult dose

Dose: Individualised. Total daily insulin requirement (adults and children) is usually 0.5-1.0 unit/kg/day; in a basal-bolus regimen 50-70% is provided by insulin aspart (mealtime bolus) and the remainder by intermediate- or long-acting insulin

Route: Subcutaneous injection (abdominal wall, thigh, upper arm, deltoid or gluteal region); may also be given by continuous subcutaneous infusion (pump) or intravenously by healthcare professionals using a vial

Frequency: Immediately before a meal (may be given soon after a meal when necessary); onset of action within 10-20 minutes, duration 3-5 hours

Rapid-acting insulin analogue; potency expressed in units. Normally used in combination with intermediate- or long-acting insulin. Rotate injection sites within the same region to reduce lipodystrophy/cutaneous amyloidosis. Dose adjustment may be needed with increased physical activity, dietary change or concomitant illness. Elderly and renal or hepatic impairment: intensify glucose monitoring and adjust dose individually. Can be used in children and adolescents from 1 year of age; safety and efficacy below 1 year not established. FlexPen delivers 1-60 units in 1-unit increments (subcutaneous use only).

Dose adjustments

Renal

Renal or hepatic impairment may reduce insulin requirements; intensify glucose monitoring and adjust the dose on an individual basis.

Dose auto-extracted from UK Summary of Product Characteristics (SPC) via the eMC; US FDA prescribing information (openFDA / DailyMed) — cross-check; US labelling may differ from UK — not yet clinician-verified. Always confirm against the product SmPC and your local formulary before prescribing.

Contraindications

Hypersensitivity to insulin aspart or to any excipient

Side effects

Hypoglycaemia (most frequently reported)
Injection-site reactions (pain, redness, hives, inflammation, bruising, swelling, itching) - usually transitory
Lipodystrophy and cutaneous amyloidosis at injection sites
Allergic reactions: urticaria, rash, eruptions (uncommon); rarely systemic hypersensitivity/anaphylactic reactions
Transient refraction anomalies and oedema at the start of treatment

Interactions

Drugs that may increase hypoglycaemia risk: oral antidiabetic agents, ACE inhibitors, angiotensin II receptor blockers, disopyramide, fibrates, fluoxetine, MAO inhibitors, pentoxifylline, pramlintide, salicylates, octreotide, sulfonamide antibiotics
Drugs that may reduce the glucose-lowering effect: corticosteroids, diuretics, danazol, oestrogens and oral contraceptives, thyroid hormones, growth hormone (somatropin), sympathomimetics, atypical antipsychotics (olanzapine, clozapine), protease inhibitors, isoniazid, niacin, glucagon

Clinical monograph

How it works

Structural modification of the insulin molecule speeds subcutaneous absorption, giving a faster onset and shorter duration than soluble human insulin and allowing dosing close to meals.

Prescribing in practice

The most important safety point is the risk of hypoglycaemia, with insulin being a high-alert medicine; prescribe in units written in full, use insulin-specific devices, and dose around meals.
Because of its rapid onset it is given just before or shortly after eating, and unexpected delays in eating increase hypoglycaemia risk.
Different insulin brands and analogues are not interchangeable, so prescribe and dispense by brand.

Monitoring

Monitor blood glucose around meals and overnight, titrating mealtime doses to carbohydrate intake and glucose response.

Counselling the patient

Inject just before eating and have fast-acting carbohydrate available in case of hypoglycaemia.
Rotate injection sites to prevent lipohypertrophy and check sites regularly.
Do not switch insulin brand or type without specialist advice.

Evidence & guidelines

Rapid-acting analogues such as insulin aspart are recommended in NICE diabetes guidance for mealtime control, and insulin is classified as a high-alert medicine.

Reference: NICE NG17/NG28; 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).

Curated clinical cross-links plus same-class fallbacks.

Calculators

Pathways