Drug effects on BP rhythm in secondary hypertension

Antihypertensive drug treatment is necessary in most patients with secondary hypertension. Only a small percentage of cases can be cured by operation or angioplasty. Because blunted or reversed nocturnal blood pressure fall is frequently found in patients with secondary hypertension, time of day of drug application is of special interest in these patients. The time structure of blood pressure over 24 hours or even longer can be obtained using ambulatory blood pressure monitoring. This is a prerequisite for individualization of antihypertensive therapy and for achievement of optimal drug effects. Chronopharmacologic aspects are playing an increasingly important role in the treatment of secondary hypertension, especially in renal forms. Recently, the first studies in this field were completed, isradipine and doxazosin in chronic renal failure and trandolapril in hypertensive diabetic subjects. Results show that restoration of normal nocturnal blood pressure fall and constitution of normal circadian rhythm are possible in patients with mild to moderate renal hypertension after evening dosing as compared to morning dosing with monotherapy. In more severe hypertension combination therapy including multiple dosing with special attention to evening application is necessary. In conclusion, optimal drug effects and individualization of antihypertensive treatment in patients with secondary forms of hypertension can be achieved using a stepped care program including chronopharmacologic regimens to restore normal circadian rhythm on a normotensive level.