Exponential-exponential cosine fitting of blood pressure decay induced by a long-acting calcium blocker, amlodipine, using home blood pressure measurement.

Blood pressure (BP) decay data obtained from homeBP measurements in six patients with uncomplicated essential hypertension treated with a calcium blocker, amlodipine, were fitted to an exponential-exponential cosine function to determine the characteristic BP-lowering effects of amlodipine. An exponential-exponential cosine function fitted the morning and night systolic BP (sBP) decay data better than a simple exponential function. From the coefficients of the equation, the estimated BP lowering, time constant for BP decay and BP oscillation induced by amlodipine for morning and night sBP were approximately 23 and 25 mmHg, 10 and 6 days, and 12 and 12 mmHg, respectively. Diastolic BP showed a similar fitting though the fitting was weaker. The fitting results indicate that the BP decay, especially the sBP decay, induced by amlodipine occurred in an oscillative fashion, and the present analysis using home BP data may provide clinically useful information about the characteristic effects of amlodipine.