Evaluation of once daily hydralazine in inadequately controlled hypertension

Despite the short plasma half-life of hydralazine, once daily Slow Apresoline has been shown to maintain blood pressure control in well controlled hypertension. In the present investigation of 118 inadequately controlled hypertensives, we have shown that 50-150 mg Slow Apresoline once daily induces a significant blood pressure reduction and is well tolerated. Normotension, i.e. supine diastolic blood pressure less than 95 mmHg, was reached in 53% of the patients. Normotension or a supine diastolic blood pressure reduction of greater than or equal to 10 mmHg was achieved in 72% of the patients, the hydralazine responders. Sixteen patients discontinued treatment due to symptoms probably related to hydralazine. Acetylator phenotyping showed that slow acetylators predominated in the group of patients discontinuing hydralazine due to side-effects. In contrast, 90% of the phenotyped non-responders were rapid acetylators, which suggests a suboptimal use of hydralazine in some rapid acetylators.