Diltiazem

Metoprolol

Formulations

IV (bolus, continuous infusion), oral (IR, ER)

IV (push), oral (IR, ER)

Onset of action (IV)

3 minutes (bolus)

20 minutes

Duration of action (IV)

1 - 3 hours (bolus), 0.5 - 10 hours (infusion)

5 - 8 hours

Half-life (IV)

3 - 4 hours (bolus), 4 - 5 hours (infusion)

2 - 6 hours