title: Crossover comparison of the pharmacokinetics of amlodipine and felodipine ER in hypertensive patients.
abstract: The pharmacokinetics of amlodipine 5 mg and felodipine ER (extended release) 5 mg o.d. after single and 2 weeks of repeated oral doses, were compared in 28 essential hypertensive patients using a crossover design. As a secondary parameter the effects of the drugs on blood pressure were assessed. Significant differences were found between all principal pharmacokinetic variables, when comparing the 2 treatments after both single and repeated dosing. The coefficients of variation of maximal drug concentration and AUC after single dosing and at steady-state were significantly higher for felodipine ER than for amlodipine. After repeated dosing the peak-to-trough plasma concentration ratio were 1.58 and 4.43 (p < 0.001) for amlodipine and felodipine ER, respectively. Both drugs lowered systolic and diastolic blood pressure to the same extent after 2 weeks of repeated dosing. No significant differences between the blood pressure lowering vs time profile of the 2 drugs were encountered. In conclusion, the interpatient drug concentration variability and the peak-to-trough plasma concentration ratio were more favorable for amlodipine compared to felodipine ER. It remains to be established whether these characteristics are also reflected in a more smooth and consistent blood pressure control.
authors.affiliation: Medical Department C, Odense University Hospital, Denmark.
authors.forename: L M
authors.initials: LM
authors.lastname: Videbaek
authors.forename: I A
authors.initials: IA
authors.lastname: Jacobsen
mesh_terms: D000328:Adult; D017311:Amlodipine / Q000493:pharmacokinetics* / Q000627:therapeutic use; D000959:Antihypertensive Agents / Q000493:pharmacokinetics* / Q000627:therapeutic use; D019540:Area Under Curve; D001794:Blood Pressure / Q000187:drug effects; D018592:Cross-Over Studies; D003692:Delayed-Action Preparations; D015736:Felodipine / Q000493:pharmacokinetics* / Q000627:therapeutic use; D005260:Female; D006207:Half-Life; D006801:Humans; D006973:Hypertension / Q000188:drug therapy / Q000378:metabolism*; D008297:Male; D008875:Middle Aged
chemical_list: D000959:Antihypertensive Agents; D003692:Delayed-Action Preparations; D017311:Amlodipine; D015736:Felodipine