TREATMENT OF ELDERLY PATIENTS WITH ISOLATED SYSTOLIC HYPERTENSION WITH ISOSORBIDE DINITRATE IN AN ASYMMETRIC DOSING SCHEDULE

Nitrates decrease pulse pressure more than mean arterial pressure (MAP ) and are advocated for the treatment of isolated systolic hypertensio n (ISH). Nitrates show drug tolerance during chronic treatment so an a symmetric dosing regimen may prevent loss of effect of nitrates. This study investigates the anti-hypertensive effect of isosorbide dinitrat e (ISDN) given in a twice daily asymmetric dosing regimen in elderly p atients with ISH. After a 6-week placebo run-in period, patients enter ed the double-blind study. Ten patients received placebo and II patien ts ISDN 20 mg b.i.d. for 8 weeks. This dose could be doubled once. Off ice systolic and diastolic blood pressures (SBP/DBP) and ambulatory BP were measured. Purse pressure was calculated as SBP-DBP. Office pulse pressure was more reduced during ISDN (17.9%) than with placebo (5%; P < 0.05). SEP and MAP decreased compared to baseline, but the changes were not statistically significant between the two groups. DBP tended to increase with ISDN compared to placebo. Mean 24-h, mean daytime an d mean night-time pulse pressure decreased after treatment with ISDN ( 10.7%, 12.1%, 7.9%, respectively). pulse pressure tended to decrease m ore during the day than during the night with ISDN. No changes could b e demonstrated with placebo. In conclusion, pulse pressure decreased w ith ISDN, resulting in a lower SEP without a decrease in DBP. The latt er may preserve coronary perfusion in ISH. With the asymmetric dosing regimen the decrease in pulse pressure was not clear at night. Whether a decrease in nocturnal BP, in addition to the spontaneous decrease, is advisable in ISH remains a matter of debate.