Pharmacokinetics of Calcium Channel Blockers
| Verapamil | Nifedipine | Nicardipine | Nimodipine | Diltiazem | | Dosage | | | | | | | Oral | 80-160 mg every 8 h | 10-30 mg every 8 h | 20 mg every 8 h | 30-60 mg every 4-6 h | 60-90 mg every 8 h | | Intravenous | 75-150 μg/kg | 5-15 μg/kg | | 10 μg/kg | 75-150 μg/kg | | Absorption (%) | | | | | | | Oral | >90 | >90 | | >90 | | | Bioavailability (%) | 10-20 | 65-70 | 30 | 5-10 | 40 | | Onset of effect (min) | | | | | | | Oral | <30 | <20 | 20-60 | 30-90 | 30 | | Sublingual | | 3 | | | | | Intravenous | 1-3 | 1-3 | 1-3 | 1-3 | | | First-pass hepatic extraction after oral administration (%) | 75-90 | 40-60 | 20-40 | 90 | 70-80 | | Protein binding (%) | 83-93 | 92-98 | 95 | 99 | 98 | | Clearance | | | | | | | Renal (%) | 70 | 80 | 55 | 20 | 35 | | Hepatic (%) | 15 | <15 | 45 | 80 | 60 | | Active metabolites | Yes | No | | Yes | | | Therapeutic plasma concentration (ng/mL) | 50-250 | 10-100 | 5-100 | 10-30 | 100-250 | | Elimination half-time (h) | 3-7 | 3-7 | 3-5 | 2 | 4-6 |
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From Reves JG, Kissin I, Lell WA, et al. Calcium entry blockers: uses and implications for anesthesiologists. Anesthesiology. 1982;57:504-518; Durand PG, Lehot JJ, Foex P. Calcium-channel blockers and anaesthesia. Can J Anaesth. 1991;38:75-89.