title: Differential effects of azelnidipine and amlodipine on sympathetic nerve activity in patients with primary hypertension.
abstract: OBJECTIVE
  Calcium channel blockers (CCBs) are used as antihypertensive agents and have a strong vasodilatory effect; however, the sympathetic activation mediated by baroreflex might cause adverse effects. A recently developed CCB, azelnidipine, decreases the heart rate (HR) while lowering blood pressure (BP), possibly by inhibiting sympathetic nerve activity in animal models. In this study, we evaluated whether azelnidipine inhibited sympathetic nerve activity, compared to amlodipine, in primary hypertensive patients.
  
  
  METHODS
  We conducted a prospective, randomized, open-label, and crossover study of 14 patients. We measured the patients' BP, HR and baroreflex sensitivity, and directly recorded muscle sympathetic nerve activity (MSNA), via microneurography, after treatment with either CCB for 8 weeks.
  
  
  RESULTS
  Although systolic and diastolic BPs did not differ between the azelnidipine and amlodipine groups, the HR in the azelnidipine group significantly decreased compared with that in the amlodipine group. MSNA was significantly reduced in the azelnidipine compared with the amlodipine group (47.7 ± 14.9 vs. 61.5 ± 10.7  bursts per 100 beats, P < 0.05). However, no significant difference was observed in terms of the baroreflex control of HR, or MSNA, between the two groups.
  
  
  CONCLUSIONS
  Our data show, first, that azelnidipine, compared with amlodipine, exerted a favorable effect on sympathetic nerve activity, without affecting baroreflex sensitivity, in hypertensive patients. These results indicate that azelnidipine might be useful for treating hypertensive patients, in whom hypertension is complicated by heart failure and ischemic heart disease.
authors: aDepartment of Disease Control and Homeostasis, Graduate School of Medical Science, Kanazawa University bKanazawa Municipal Hospital, Kanazawa, Japan *Hisayoshi Murai and Shuichi Kaneko contributed equally to this article.
authors: Jun-ichiro
authors: J
authors: Inomata
authors: Hisayoshi
authors: H
authors: Murai
authors: Shuichi
authors: S
authors: Kaneko
authors: Takuto
authors: T
authors: Hamaoka
authors: Tatsunori
authors: T
authors: Ikeda
authors: Daisuke
authors: D
authors: Kobayashi
authors: Soichiro
authors: S
authors: Usui
authors: Hiroshi
authors: H
authors: Furusho
authors: Yu
authors: Y
authors: Sugiyama
authors: Shigeo
authors: S
authors: Takata
authors: Masayuki
authors: M
authors: Takamura
mesh_terms: D017311:Amlodipine / Q000494:pharmacology*; D000959:Antihypertensive Agents / Q000494:pharmacology*; D001383:Azetidinecarboxylic Acid / Q000031:analogs & derivatives* / Q000494:pharmacology; D017704:Baroreflex / Q000187:drug effects* / Q000502:physiology; D001794:Blood Pressure / Q000187:drug effects / Q000502:physiology; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D018592:Cross-Over Studies; D004095:Dihydropyridines / Q000494:pharmacology*; D000075222:Essential Hypertension; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D006973:Hypertension / Q000188:drug therapy* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D013564:Sympathetic Nervous System / Q000187:drug effects*
chemical_list: D000959:Antihypertensive Agents; D002121:Calcium Channel Blockers; D004095:Dihydropyridines; D017311:Amlodipine; D001383:Azetidinecarboxylic Acid; C061679:azelnidipine