Metoprolol

Chemical

Amide

Use

  1. Hypertension
  2. Post AMI
  3. Arrhythmias

Presentation

Tablets 25/50mg

Clear, colourless solution 1mg/mL

Dose

PO: 50 – 100mg BD

IV: 1 – 2mg boluses

Route

PO/IV

DoA

~4hrs

MoA

Competitive antagonist at β1 adrenoreceptors

Antagonises effects of catecholamines

PD

CVS:

  • – VE CHRONO, – VE DROMO, – VE INOTROPY
  • ↓myocardial O2 consumption

Metabolic: ↑TAGs, HDL, cholesterol

PK

A

50% OBA

D

10% PPB

M

Hepatic; 60% 1st pass metabolism

Inactive metabolites

E

Metabolites cleared in urine

<10% unchanged

t ½ B 6hrs

Adverse Effects

  • Hypotension
  • Bradycardia
  • Masks hypoglycaemia