Midazolam (Surgical — Anxiolysis/Sedation)

SOURCE: eMC UK SPC, 'Midazolam 1 mg/ml solution for injection/infusion', §4.2. Titration is strongly recommended; administer with care in patients over 60, debilitated or chronically ill patients. CONSCIOUS SEDATION, patients over 60 / debilitated / chronically ill: initial 0.5 to 1 mg IV 5 to 10 minutes before the procedure, further 0.5 to 1 mg as necessary, titrated very slowly (peak effect takes longer). ANAESTHESIA PREMEDICATION (ASA I-II, under 60 years): 1 to 2 mg IV repeated as necessary, or 0.07 to 0.1 mg/kg IM 20 to 60 minutes before induction; over 60 / debilitated / chronically ill: 0.5 mg IV initially, slowly increased as needed, or 0.025 to 0.05 mg/kg IM; usual dose 2 to 3 mg with concomitant narcotics (reduce midazolam dose). ANAESTHESIA INDUCTION: premedicated adults under 60 years 0.15 to 0.2 mg/kg IV; non-premedicated adults under 60 years 0.3 to 0.35 mg/kg IV; in refractory cases up to a total of 0.6 mg/kg may be used (may prolong recovery); premedicated adults over 60 / debilitated / chronically ill 0.05 to 0.15 mg/kg IV; non-premedicated over 60 years 0.15 to 0.3 mg/kg; non-premedicated debilitated or severe systemic disease 0.15 to 0.25 mg/kg. Give in increments of not more than 5 mg over 20 to 30 seconds with 2-minute intervals; if used with other induction agents, reduce the initial dose of all agents significantly, sometimes to as low as 25%. SEDATIVE COMPONENT IN COMBINED ANAESTHESIA: intermittent IV doses of 0.03 to 0.1 mg/kg or continuous IV infusion of 0.03 to 0.1 mg/kg/h, typically with analgesics (lower doses in adults over 60, debilitated or chronically ill). ICU SEDATION: IV loading dose 0.03 to 0.3 mg/kg given slowly in increments of 1 to 2.5 mg over 20 to 30 seconds with 2-minute intervals, then maintenance infusion 0.03 to 0.2 mg/kg/h; reduce or omit the loading dose and reduce maintenance in hypovolaemia, vasoconstriction or hypothermia; give strong analgesics first. Hepatic impairment reduces clearance — the required dose may be reduced and vital signs monitored. §4.4 and §4.8 text was truncated at the source-fetch limit.

dosePerKg is left null because the SPC gives DIFFERENT per-kg ranges by age band, route and indication — carrying one number would risk it being applied to the wrong band. CONSCIOUS SEDATION (IV): under 6 months — not recommended (predisposed to airway obstruction and hypoventilation); 6 months to 5 years — initial 0.05 to 0.1 mg/kg, up to 0.6 mg/kg may be needed, total not to exceed 6 mg; 6 to 12 years — initial 0.025 to 0.05 mg/kg, up to a total of 0.4 mg/kg (10 mg maximum); 12 to 16 years — use adult dosages. RECTAL (over 6 months): 0.3 to 0.5 mg/kg total, given at once, not repeated. INTRAMUSCULAR: 0.05 to 0.15 mg/kg (conscious sedation, 1 to 15 years). PREMEDICATION (over 6 months): rectal 0.3 to 0.5 mg/kg 15 to 30 minutes before induction; IM 0.08 to 0.2 mg/kg (1 to 15 years). ICU SEDATION: neonates under 32 weeks gestational age — continuous IV infusion 0.03 mg/kg/h (0.5 micrograms/kg/min); neonates over 32 weeks and children up to 6 months — 0.06 mg/kg/h (1 microgram/kg/min), no IV loading dose in preterm infants, neonates or infants up to 6 months; children over 6 months (intubated and ventilated) — loading dose 0.05 to 0.2 mg/kg IV slowly over 2 to 3 minutes, then continuous infusion 0.06 to 0.12 mg/kg/h (1 to 2 micrograms/kg/min), adjusted by about 25% steps as required. In premature infants, neonates and children under 15 kg, solutions more concentrated than 1 mg/ml are not recommended — dilute to 1 mg/ml. Verify all under-18 dosing against a children's formulary.