Effects of monotherapy and withdrawal of antihypertensive drugs in the treatment of hypertension.

The final number of antihypertensive drugs used in the long-term treatment of a given patient is not always predictable at the start of therapy. By reviewing clinical records, we retrospectively examined the relationship between pretreatment blood pressure and the final number of drugs administered in 282 patients with mild to moderate hypertension who had been treated for 5 years or more (average 9.7 years). After years of treatment approximately one third and one half of 137 patients with a pretreatment diastolic blood pressure of between 90 and 104 mmHg were well controlled with combined therapy and monotherapy, respectively. The drugs had been withdrawn in the remaining 17% for 12 months or more. Lower pretreatment systolic blood pressure and lower pretreatment QRS voltage were signs favorable for withdrawal of the drugs. Combined therapy was required in more than half the patients with higher pretreatment diastolic blood pressure.