Midazolam (IV/IM)

SOURCE: UK SPC (eMC) for Midazolam 1 mg/ml solution for injection/infusion, §4.2 (https://www.medicines.org.uk/emc/product/13192/smpc). CONSCIOUS SEDATION, ADULTS ≥60 YEARS / DEBILITATED / CHRONICALLY ILL: initial dose 0.5–1 mg given 5–10 minutes before the procedure, with additional doses of 0.5–1 mg titrated very slowly as necessary; total dose usually less than 3.5 mg. ANAESTHESIA PREMEDICATION (ASA I–II, under 60 years): 1–2 mg intravenously repeated as necessary, or 0.07–0.1 mg/kg intramuscularly (deep into the muscle mass, 20 to 60 minutes before induction); over 60 years / debilitated / chronically ill: recommended IV initial dose 0.5 mg increased slowly as needed, or IM 0.025–0.05 mg/kg; with concomitant narcotics the midazolam dose should be reduced (usual dosage 2–3 mg). ANAESTHESIA INDUCTION: premedicated adults under 60 years usually 0.15–0.2 mg/kg IV; non-premedicated adults under 60 years 0.3–0.35 mg/kg IV, with additional doses of about 25% of the initial dose if full induction is sought and up to a total of 0.6 mg/kg in refractory cases (higher doses may prolong recovery); premedicated adults over 60 years, debilitated or chronically ill 0.05–0.15 mg/kg IV over 20–30 seconds with a 2-minute wait; non-premedicated adults over 60 years 0.15–0.3 mg/kg; non-premedicated debilitated patients or those with severe systemic disease usually 0.15–0.25 mg/kg. Each induction increment of not more than 5 mg should be injected over 20–30 seconds with 2-minute intervals between doses; if used with other induction agents the initial doses of all medicines should be significantly reduced, sometimes to as low as 25% of the usual initial dose. SEDATIVE COMPONENT IN COMBINED ANAESTHESIA: intermittent IV doses of 0.03–0.1 mg/kg or continuous IV infusion of 0.03–0.1 mg/kg/h, typically with analgesics; lower doses in patients over 60 years, debilitated or chronically ill. SEDATION IN THE INTENSIVE CARE UNIT: IV loading dose 0.03–0.3 mg/kg given slowly in increments — each 1 to 2.5 mg dose over 20–30 seconds with 2-minute intervals — followed by an IV maintenance dose of 0.03–0.2 mg/kg/h; reduce or omit the loading dose and reduce the maintenance dose in patients with hypovolaemia, vasoconstriction or hypothermia; if strong analgesics are co-administered they should be given first; assess sedation level regularly — long-term sedation may lead to tolerance requiring dose increases, and physical dependence with withdrawal symptoms on abrupt cessation. HEPATIC IMPAIRMENT: clearance is reduced with a longer terminal half-life — the required dose may be reduced and vital signs properly monitored. ADMINISTRATION: midazolam should be given only by experienced physicians in a setting fully equipped for monitoring and support of respiratory and cardiovascular function. GAP — this SPC covers IV/IM/rectal use for conscious sedation, premedication, induction, combined anaesthesia and ICU sedation. It does NOT contain a status epilepticus regimen or any buccal (oromucosal) dosing; the '10 mg buccal/IM for status epilepticus' shown on this page must be sourced from a buccal midazolam product SPC or national guidance and verified by the clinician.

SPC §4.2 gives per-kg paediatric dosing as RANGES, so no single dosePerKg figure can be stated. CONSCIOUS SEDATION — not recommended under 6 months of age (predisposition to airway obstruction and hypoventilation); 6 months to 5 years: initial dose 0.05–0.1 mg/kg IV, up to 0.6 mg/kg may be needed to reach the desired effect but the total dosage should not exceed 6 mg; 6 to 12 years: initial dose 0.025–0.05 mg/kg IV, total dosage may need to reach 0.4 mg/kg with 10 mg as the maximum; 12 to 16 years: use the recommended adult dosages. Rectal (>6 months): total dose usually 0.3–0.5 mg/kg as a single administration — avoid repeated rectal administration. Intramuscular (1–15 years): 0.05–0.15 mg/kg — the IM route should only be used in exceptional cases as it is painful; rectal is preferred. ANAESTHESIA PREMEDICATION (over 6 months): rectal 0.3–0.5 mg/kg 15–30 minutes before induction; intramuscular 0.08–0.2 mg/kg. ICU SEDATION: neonates born before 32 weeks gestation — continuous IV infusion 0.03 mg/kg/h (0.5 micrograms/kg/min); neonates born after 32 weeks gestation and children up to 6 months — 0.06 mg/kg/h (1 microgram/kg/min); IV loading doses are not recommended in preterm infants, neonates and children up to 6 months, the infusion rate should instead be higher during the first hours; children over 6 months (intubated and ventilated) — loading dose 0.05–0.2 mg/kg IV slowly over 2 to 3 minutes, then continuous infusion 0.06–0.12 mg/kg/h (1 to 2 micrograms/kg/min), adjusted generally by 25% of the current rate. In premature infants, neonates and children with body weight below 15 kg, midazolam solutions with a concentration above 1 mg/ml are not recommended — dilute to 1 mg/ml. Careful monitoring of respiratory rate and oxygen saturation is required.