Esmolol

UNITS WARNING — the loading dose is a RATE in micrograms/kg/MINUTE, not a bolus in micrograms/kg; it must be given over a defined, short period. GAP IN THE SOURCE: for the supraventricular tachyarrhythmia indication the SPC sets out the loading and maintenance sequence in a 'Flow Chart for Initiation and Maintenance of Treatment' whose contents were NOT captured in this fetch, so the DURATION of the 500 micrograms/kg/minute loading infusion for that indication is not established here and MUST be confirmed against the full SPC before use. The retrieved SPC text bounds the 500 micrograms/kg/minute rate only in the perioperative settings (see below). US CROSS-CHECK (openFDA, Esmolol Hydrochloride Injection): 'Optional loading dose (500 mcg per kg over 1 minute), then 50 mcg per kg per min for 4 min', with step-wise titration (optional loading dose then 100, then 150, then if necessary 200 mcg/kg/min, each for 4 minutes), titrating at intervals of 4 minutes or more; maintenance infusions may be continued for up to 48 hours. PERIOPERATIVE TACHYCARDIA AND HYPERTENSION (eMC): intraoperative, during anaesthesia when immediate control is required — a bolus injection of 80 mg over 15 to 30 seconds followed by a 150 micrograms/kg/minute infusion, titrated as required up to 300 micrograms/kg/minute. On awakening from anaesthesia — an infusion of 500 micrograms/kg/minute given FOR 4 MINUTES followed by a 300 micrograms/kg/minute infusion. Post-operatively when time for titration is available — a loading dose of 500 micrograms/kg/minute given OVER 1 MINUTE before each titration step, with titration steps of 50, 100, 150, 200, 250 and 300 micrograms/kg/minute each given over 4 minutes, stopping at the desired therapeutic effect. TITRATING DOWN: as the desired heart rate or safety end-point (e.g. lowered blood pressure) is approached, OMIT the loading dose and reduce the incremental maintenance infusion from 50 to 25 micrograms/kg/minute or lower (elsewhere the SPC states reduce the incremental infusion to 12.5 to 25 micrograms/kg/minute); 25 micrograms/kg/minute doses may be used. Discontinue Brevibloc when heart rate or blood pressure rapidly approach or exceed a safety limit, then restart WITHOUT a loading infusion at a lower dose once they return to an acceptable level. DURATION: administration for longer than 24 hours has not been thoroughly evaluated; infusion durations greater than 24 hours should only be used with caution. Terminate the infusion gradually because of the risk of rebound tachycardia and rebound hypertension; caution with abrupt discontinuation in coronary artery disease. TRANSITION TO ALTERNATIVE DRUGS: within the first hour after the first dose of the alternative drug, reduce the Brevibloc infusion rate by one-half (50%); after the second dose of the alternative drug, if satisfactory control is maintained for the first hour, discontinue the Brevibloc infusion. MONITORING: continuously monitor blood pressure and ECG in all patients. If a local infusion site reaction develops, use an alternative site and take care to prevent extravasation. ELDERLY: treat with caution, starting with a lower dosage. HEPATIC: no special precautions needed in liver insufficiency. PAEDIATRIC: safety and efficacy in children up to 18 years have not been established; Brevibloc is not indicated for use in the paediatric population and NO posology recommendation can be made.