BLACK BOX WARNING
- abrupt withdrawal
metoprolol tartrate
Brand: Lopressor
⚠ BBW Prototype: metoprolol-succinate
Drug Class: beta-blocker
Drug Family: antihypertensive
Subclass: selective beta-1 blocker (immediate-release)
Organ Systems: cardiovascular
Mechanism of Action
Cardioselective beta-1 antagonist; IR formulation requires twice-daily dosing.
beta-1 adrenergic receptor
Indications
- hypertension
- acute MI (IV)
- angina
- AF rate control
Contraindications
- decompensated HF
- cardiogenic shock
- severe bradycardia
- high-degree AV block
Adverse Effects
Common
- bradycardia
- fatigue
- dizziness
Serious
- bronchospasm
- heart block
Pharmacokinetics (ADME)
| Absorption | 50% bioavailability |
| Distribution | moderate lipophilicity |
| Metabolism | hepatic CYP2D6 |
| Excretion | renal |
| Half-life | 3-7 hours |
| Onset | 30-60 min oral; immediate IV |
| Peak | 1-2 hours |
| Duration | 6-12 hours |
| Protein Binding | 12% |
| Vd | 3.2-5.6 L/kg |
Drug Interactions
| Drug / Agent | Mechanism | Severity |
|---|---|---|
| verapamil/diltiazem | additive AV block | major |
| CYP2D6 inhibitors | increased plasma levels | moderate |
Nursing Considerations
- IV form used in acute MI and SVT
- Check pulse before each dose; hold if <50 bpm
- Twice-daily oral dosing required (vs succinate once-daily)
- Do NOT substitute tartrate for succinate in HFrEF studies
Clinical Pearls
- IV form used for acute rate control in AF/SVT and acute MI
- NOT the preferred formulation for chronic HF (succinate XL has the evidence)
Safety Profile
Pregnancy use-with-caution
Lactation use-with-caution
Renal Adjustment Not required
Hepatic Adjustment Required
TDM Not required
Concordance Terms
Cross-referenced clinical concepts — click any term to see all content where it appears.