Diabetes & insulin

Insulin

TypeGenericBrandTypical useOnsetPeakDuration
Rapid-actingInsulin aspartNovoRapidPre-meal bolus10–20 min1–3 h3–5 h
Rapid-actingInsulin lisproHumalogPre-meal bolus15–30 min1–2 h4–5 h
Short-actingRegular insulinActrapidCorrection / pre-meal / IV drip30 min2–4 h6–8 h
IntermediateNPH insulinInsulatard / Humulin NBID basal60–90 min4–6 h12–18 h
BasalInsulin glargineLantusOD basal60–120 minNo peak~24 h
Basal (ultra-long)Insulin glargine U300ToujeoLong-acting basal60–120 minNo peak> 24 h
Basal (ultra-long)Insulin degludecTresibaUltra-long basal~1 hNo peak~42 h
IV insulinRegular insulin (IV)Humulin RDKA, ICU insulin dripImmediateVariesShort
PremixedBiphasic insulin aspartNovoMix 30Premixed (basal + bolus)10–20 min1–4 hUp to 24 h
PremixedBiphasic human insulin 30/70Mixtard 30Premixed, commonly used30 min2–8 hUp to 24 h

Switching basal insulin (Lantus ↔ Toujeo ↔ Tresiba): start at ~1:1 total daily units and titrate. Toujeo (U300) often needs ~10–15% more to match; Tresiba is long-acting and forgiving. Converting twice-daily NPH to a once-daily basal: start at ~80% of the total daily NPH dose.

Oral & non-insulin diabetes medications

Class (examples)Inpatient useNotes
Biguanide — metformin (Glucophage)StopRisk of lactic acidosis
Sulfonylureas — gliclazide (Diamicron), glimepiride (Amaryl)AvoidHigh hypoglycemia risk
DPP-4 inhibitors — Januvia, Trajenta, Galvus, OnglyzaContinue if stableLow risk, safe in eating patients
GLP-1 RAs — Ozempic, Victoza, TrulicityAvoidNausea, limited inpatient benefit
SGLT2 inhibitors — Forxiga, JardianceAvoidRisk of DKA, dehydration
Thiazolidinediones — pioglitazone (Actos)AvoidRisk of edema, HF
Combinations — Synjardy, Xigduo, JanumetPer componentsUsually hold the SGLT2/metformin part inpatient
Alpha-glucosidase inhibitors — acarboseNot usedIneffective if NPO

Correction (sliding) scale

Capillary glucoseRapid-acting insulin SC
10–14 mmol/L2 units
14–17 mmol/L4 units
17–20 mmol/L6 units
> 20 mmol/L8 units + check ketones, call senior

A subcutaneous correction scale on top of the patient’s usual regimen. This is a conservative scale for an insulin-sensitive adult: reduce in the frail, elderly, or CKD (hypo risk), and expect higher requirements in insulin-resistant patients (obesity, high-dose steroids, large home insulin doses). Titrate to the individual. For DKA/HHS or the nil-by-mouth patient, use an IV variable-rate insulin infusion (VRIII) per local protocol, not this SC scale.

Educational reference for clinicians. Doses are typical adult starting points — cross-check current local policy, the formulary, and renal/hepatic function before prescribing. Last reviewed: July 2026.

Last reviewed · July 2026

MOC