Clinical trial of arotinolol in the treatment of hypertension: Dippers vs.non-dippers

To compare the effects of an a, P blocker, arotinolol, in the treatment of essential hypertension between patients with a dipper and those with a non- dipper profile by means of 24-h ambulatory blood pressure monitoring (ABPM) , a multicenter single blind parallel trial was carried out in five clinica l centers. After a one-week single blind placebo run-in period, the patient s underwent ABPM if their clinic diastolic blood pressure (DBP) ranged from 90-109 mmHg and their clinic systolic blood pressure (SBP) was < 180 mmHg. They were divided into two groups according to the absence (non-dipper gro up, 24 cases) or presence (dipper group, 23 cases) of nocturnal BP reductio n greater than or equal to 10% of daytime BP. ABPM was measured again at th e end of the active treatment phase. All patients were given Arotinolol 10- 20 mg twice daily for 4 weeks. Twenty four-hour systolic and diastolic aver age BPs (MSBP, MDBP), 24-h systolic and diastolic blood pressure load (LS B ID, LDBP), daytime systolic and diastolic average BPs (dMSBP, dMDBP), dayti me systolic and diastolic blood pressure load (dLSBP, dLDBP), nighttime sys tolic and diastolic average Bps (nMSBP, nMDBP) and nighttime systolic and d iastolic blood pressure load (nLSBP, nLDBP) were calculated. Arotinolol was effective in 78.2% of dippers and 54.2% of non-dippers, but the difference in effectiveness between these groups was not statistically significant. A fter treatment, SBP and DBP-including 24-h, daytime and nighttime systolic and diastolic BPs- were significantly reduced in both groups. During the da ytime period, the systolic and diastolic blood pressures were significantly reduced in both dippers and non-dippers, while nighttime systolic and dias tolic blood pressures were significantly reduced only in the non-dipper gro up. No significant changes were found in the dipper group over this period. In conclusion, Arotinolol, which can be dosed twice daily, is an effective antihypertensive agent which effectively lowers blood pressure during the day while reducing nighttime blood pressure more in non-dippers than in dip pers, without excessive lowering blood pressure in the latter.