[When blood pressure control is a problem. Refractory hypertension is rare]

Hypertension is considered refractory when the use of three pharmacologically different antihypertensives (included a diuretic, a sympathetic blocker and a vasodilator) given at maximum dose fails to lower the blood pressure to below 140/90 mmHg. In the event of isolated systolic hypertension, the value should be reduced to below 140 mmHg. A truly refractory form may be assumed in some 2-5% of all hypertensives, and must be differentiated from a pseudo form in which such factors as counter-regulatory mechanisms, inadequate use of general measures, inadequate antihypertensive therapy, interactions with other drugs, or secondary hypertension may play a role. Refractory patients in whom the underlying cause cannot be identified should be referred to an appropriate specialist. Diuretic treatment should first be optimized and antihypertensive doses maximized (with consideration being given to side effects). Further substances such as minoxidil in combination with a beta-blocker and a diuretic may be used.