Metoprolol (IV/Oral — Cardiology)

SOURCE: UK SPC (eMC) for Betaloc 1 mg/ml Solution for Injection, §4.2 (https://www.medicines.org.uk/emc/product/866/smpc). The dose must always be adjusted to the individual requirements of the patient. MYOCARDIAL INFARCTION (early intervention): suitable patients should present within 12 hours of the onset of chest pain; IV therapy should be initiated in a coronary care or similar unit once haemodynamically stable — commence 5 mg IV every 2 minutes to a maximum of 15 mg total, as determined by blood pressure and heart rate; oral therapy should then commence 15 minutes after the last injection with 50 mg every 6 hours for 48 hours; patients who fail to tolerate the full intravenous dose should be given half the suggested oral dose. HOLD CRITERIA: the second or third dose should not be given if systolic blood pressure is <90 mmHg, heart rate <40 beats/min, P-Q time >0.26 seconds, or if there is any aggravation of dyspnoea or cold sweating; monitor haemodynamic status after each of the three 5 mg IV doses. DURING ANAESTHESIA: 2–4 mg injected slowly IV at induction is usually sufficient to prevent arrhythmias, and the same dosage can control arrhythmias developing during anaesthesia; further injections of 2 mg may be given as required to a maximum overall dose of 10 mg. CAUTION: because of the risk of a pronounced drop in blood pressure, IV administration to patients with a systolic blood pressure below 100 mmHg should only be given with special care. WITHDRAWAL: should not be withdrawn abruptly — when possible withdraw gradually over 10–14 days in diminishing doses to 25 mg daily for the last 6 days. HEPATIC IMPAIRMENT: dose adjustment normally not needed in liver cirrhosis, but a reduction may be necessary in severe hepatic dysfunction. ELDERLY: dose adjustment not needed, but careful dose titration is important in all patients. PAEDIATRIC: safety and efficacy in children has not been established. GAP — this is the INJECTION SPC. It contains no chronic oral maintenance regimen; the oral doses shown on this page (25–200 mg twice daily immediate-release, or 47.5–190 mg once daily succinate XL) are NOT in this label and must be sourced from the relevant oral metoprolol tartrate / succinate SPC. The only oral dose stated here is the post-MI 50 mg every 6 hours for 48 hours.