Standard Dosing for Metoprolol
Metoprolol comes as immediate-release (metoprolol tartrate, brand Lopressor) and extended-release (metoprolol succinate, brand Toprol XL) formulations with different dosing schedules. Dosing varies by condition, patient age, kidney/liver function, and response. Always follow prescribing information or a doctor's guidance.
Hypertension Dosing
- Immediate-release (tartrate): Start at 100 mg/day in 2 divided doses; increase weekly if needed to max 450 mg/day.[1]
- Extended-release (succinate): Start at 25-100 mg once daily; max 400 mg/day.[1]
Angina Pectoris Dosing
- Immediate-release: 100 mg/day in 2 divided doses; may increase to 400 mg/day.[1]
- Extended-release: 100 mg once daily; max 400 mg/day.[1]
Heart Failure Dosing (NYHA Class II-IV)
- Extended-release only: Start at 12.5-25 mg once daily; titrate slowly (e.g., double every 2 weeks) to target 200 mg/day, based on tolerance.[1]
Post-Myocardial Infarction Dosing
- Immediate-release: 200 mg/day in divided doses for long-term use, starting early in acute phase if stable.[1]
Migraine Prevention Dosing
- Immediate-release: 100 mg/day in 2 divided doses.[1]
How to Take It
Take with food to improve absorption. Extended-release tablets must be swallowed whole—do not crush or chew. Missed dose: Take as soon as remembered unless near next dose; do not double up.
Dosing Adjustments
- Elderly or liver impairment: Start lower (e.g., 50 mg/day immediate-release or 25 mg/day extended-release); titrate cautiously.[1]
- Kidney impairment: No major adjustment needed, but monitor.[1]
- Children: Not FDA-approved for most uses; off-label hypertension dosing is 1-2 mg/kg/day divided, max 200 mg/day.[2]
What If You Miss a Dose or Overdose?
Missing one dose usually isn't critical—resume schedule. Overdose symptoms include slow heart rate, low blood pressure, breathing issues; seek emergency care immediately. Activated charcoal or glucagon may be used in hospital.[1]
Common Side Effects Affecting Dosing
Fatigue, dizziness, or bradycardia may require dose reduction. Abrupt stopping risks rebound hypertension or angina—taper over 1-2 weeks.[1]
[1]: https://www.accessdata.fda.gov/drugsatfda_docs/label/2011/017963s038lbl.pdf (Lopressor label)
[2]: Lexicomp/Pediatrics dosing reference