Blood Pressure Elevation after Withdrawal of Antihypertensive Drugs in the Aged

The return of the elevated blood pressure after discontinuing antihypertensive drugs was investigated in 65 hypertensive aged patients. The blood pressure was elevated at a certain level one month after the withdrawal of drugs, and remained around the same level for six months. The lower the blood pressure during the antihypertensive treatment, the lower the blood pressure level reached after the withdrawal of drugs. The elevation of systolic blood pressure over 160mmHg after the withdrawal of drugs was observed in 65% and in 87.5% patients who showed the systolic pressures of 149 or less and 150 to 159mmHg during the treatment respectively. The elevation of systolic pressures in patients with systolic pressure of 160 to 169, and 170 to 179, were by 56.3% and 67.1% respectively, and systolic blood pressure remained the same level in patients with blood pressure over 180mmHg. As a whole, 26.5% remained at 159mmHg or less after withdrawal of drugs. The elevation of diastolic blood pressure over 90mmHg after the withdrawal of drugs was observed in 13.6% and 53.6% of patients who showed the diastolic pressures of 79 or less and 80 to 89mmHg during the treatment respectively. Patients with diatolic pressure of 90 to 99 showed the elevation of diastolic pressure by 41.7%. and no elevation of diastolic pressure was observed in patients with diastolic pressure over 100mmHg. Thus, 64.0% remained at 89mmHg or less after withdrawal of drugs, indicating one of the characteristics of aged hypertension. Drugs used during the treatment were mainly thiazide diuretics, and no difference in elevation of blood pressure after withdrawal was observed between one drug treatment and two or more drugs treatment.