How is pharmacokinetics of Ca channel blockers?

A: PO (all), IV (Diltiazem and verapamil) Bioavailability (Nifedipine, diltiazem and verapamil low bioavailability due to first-pass) Onset (w/in 30-60 min oral dose except ones that are more slowly acting (Amlodipine)) Distribution (bind plasma proteins (90%) most have short half-life (3-8 hours) except amlodipine no need for sustained release formulation) Excretion (Nifedipine and Verapamil by kidney, Diltiazem by liver)