PURPOSE: Clopidogrel is metabolized by the hepatic cytochrome P450 (CYP) system into its active thiol metabolite. CYP3A4 is involved in the metabolism of both clopidogrel and dihydropyridine calcium channel blockers (CCBs). A few reports have suggested an inhibitory interaction between CCBs and clopidogrel. Accordingly, the aim of this study was to determine the effect of CCBs on the antiplatelet activity of clopidogrel by serial P2Y12 reaction unit (PRU) measurements. MATERIALS AND METHODS: We assessed changes in antiplatelet activity in patients receiving both clopidogrel and CCBs for at least 2 months prior to enrollment in the study. The antiplatelet activity of clopidogrel was measured by VerifyNow P2Y12 assay in the same patient while medicated with CCBs and at 8 weeks after discontinuation of CCBs. After discontinuation of the CCBs, angiotensin receptor blockers were newly administered to the patients or dosed up for control of blood pressure. RESULTS: Thirty patients finished this study. PRU significantly decreased after discontinuation of CCBs (238.1+/-74.1 vs. 215.0+/-69.3; p=0.001). Of the 11 patients with high post-treatment platelet reactivity to clopidogrel (PRU> or =275), PRU decreased in nine patients, decreasing below the cut-off value in seven of these nine patients after 8 weeks. Decrease in PRU was not related to CYP2C19 genotype. CONCLUSION: CCBs inhibit the antiplatelet activity of clopidogrel.
Aged ; Aged, 80 and over ; Blood Platelets/*drug effects ; Calcium Channel Blockers/*therapeutic use ; Dihydropyridines/*therapeutic use ; Drug Interactions ; Female ; Humans ; Male ; Middle Aged ; Platelet Aggregation Inhibitors/*therapeutic use ; Ticlopidine/*analogs & derivatives/therapeutic use

OBJECTIVETo compare the effects of amlodipine, benidipine and nifedipine on myocardial hypertrophy and evaluate the underlying mechanism.

METHODSMyocardial hypertrophy model was created by transverse aortic constriction (TAC) in C57 BL/6 mice, and plasma catecholamine concentrations were measured 7 days after surgery to confirm the sympathetic activation. The 3 drugs were administered in TAC mice for 7 days and cardiac hypertrophy was evaluated according to the heart-to-body weight ratio (HW/BW). Effects of those drugs on the protein synthesis stimulated by phenylephrine in cultured neonatal cardiac myocytes were also examined.

RESULTSHW/BW and plasma concentrations of catecholamine were significantly increased in TAC mice one week after surgery in comparison with to sham-operated mice. One week after TAC, the HW/BW ratio was significantly lower in the amolodipine but not nifedipine-treated group than in the TAC group. Administration of nifedipine via minipump infusion for one week did not decrease HW/BW ratio. Treatment with amlodpine or benidipine, but not nifedipine, decreased the neonatal rat myocyte protein synthesis induced by phenylephrine stimulation.

CONCLUSIONAntihypertrophic effect of DHEs on myocardium is dependent on their potential of blocking N-type calcium channel, and the underlying mechanism involves the sympathetic inhibition.

Amlodipine ; pharmacology ; therapeutic use ; Animals ; Calcium Channel Blockers ; pharmacology ; therapeutic use ; Calcium Channels, N-Type ; drug effects ; Cardiomegaly ; drug therapy ; etiology ; Dihydropyridines ; pharmacology ; therapeutic use ; Disease Models, Animal ; Male ; Mice ; Mice, Inbred C57BL ; Nifedipine ; pharmacology ; therapeutic use

BACKGROUNDCentral blood pressure (BP) is pathophysiologically more important than peripheral BP for the pathogenesis of cardiovascular disease. Arterial stiffness is also a good predictor of cardiovascular morbidity and mortality. The effects of benidipine, a unique dual L-/T-type calcium channel blocker, on central BP have not been reported. This study aimed to compare the effect of benidipine and losartan on the central BP and arterial stiffness in mild to moderate essential hypertensives.

METHODSThis 24 weeks, multi-center, open label, randomized, active drug comparative, parallel group study was designed as a non-inferiority study. The eligible patients (n = 200) were randomly assigned to receive benidipine (n = 101) or losartan (n = 99). Radial artery applanation tonometry and pulse wave analysis were used to measure the central BP, pulse wave velocity (PWV) and augmentation index (AIx). We also measured the metabolic and inflammatory markers.

RESULTSAfter 24 weeks, the central BP decreased significantly from baseline by (16.8 ± 14.0/10.5 ± 9.2) mmHg (1 mmHg = 0.133 kPa) (systolic/diastolic BP; P < 0.001) in benidipine group and (18.9 ± 14.7/12.1 ± 10.2) mmHg (P < 0.001) in losartan group respectively. Both benidipine and losartan groups significantly lowered peripheral BP (P < 0.001) and AIx (P < 0.05), but there were no significant differences between the two groups. The mean aortic, brachial and femoral PWV did not change in both groups after 24-week treatment. There were no significant changes of the blood metabolic and inflammatory biomarkers in each group.

CONCLUSIONBenidipine is as effective as losartan in lowering the central and peripheral BP, and improving arterial stiffness.

Adolescent ; Adult ; Aged ; Angiotensin II Type 1 Receptor Blockers ; therapeutic use ; Blood Pressure ; drug effects ; Calcium Channel Blockers ; therapeutic use ; Dihydropyridines ; adverse effects ; therapeutic use ; Essential Hypertension ; Female ; Humans ; Hypertension ; drug therapy ; physiopathology ; Losartan ; adverse effects ; therapeutic use ; Male ; Middle Aged ; Vascular Stiffness ; drug effects

BACKGROUNDCombination therapy is an effective method to reduce the blood pressure (BP) for patients with hypertension. This study was performed to evaluate the efficacy and safety of benazepril/lercanidipine compared with benazepril alone in patients with mild-to-moderate hypertension.

METHODSOne hundred and eighty-one patients with mild-to-moderate primary hypertension were assigned in this randomized, single-blind, parallel-group study and were randomly divided into group A (benazepril 10 mg/lercanidipine 10 mg) and group B (benazepril 10 mg) for 8 weeks. At 4 weeks, the dosage of Benazepril was titrated up to 20 mg if the diastolic blood pressure (DBP) remained ≥ 90 mmHg. BP control and side effects were evaluated at the end of 1, 4 and 8 weeks.

RESULTSThe baseline characteristics of the two groups were similar. The BP in both groups decreased from the baseline (P < 0.05). At the end of 4 and 8 weeks, Benazepril/Lercanidipine produced greater BP reduction than Benazepril alone (P < 0.05). The comparison of the rate of BP control for the benazepril/lercanidipine and benazepril groups at the end of 1, 4, and 8 weeks were 41.2% vs. 37.6% (P > 0.05), 67.1% vs. 44.7% (P < 0.05), and 71.8% vs. 45.9% (P < 0.05). There was no significant difference of side effects between the two groups.

CONCLUSIONThe benazepril/lercanidipine combination is more effective in reducing BP than benazepril alone, while it does not increase the incidence of side effects.

Aged ; Angiotensin-Converting Enzyme Inhibitors ; therapeutic use ; Benzazepines ; administration & dosage ; adverse effects ; therapeutic use ; Blood Pressure ; drug effects ; Calcium Channel Blockers ; administration & dosage ; Dihydropyridines ; administration & dosage ; adverse effects ; Drug Therapy, Combination ; Female ; Humans ; Hypertension ; drug therapy ; Male ; Middle Aged ; Single-Blind Method