【例1】男,70岁。因疲乏无力4个月于2000年6月20日就诊,既往有高血压病史,曾长期服用硝苯吡啶,因踝关节水肿而停服。查体除收缩压>140mmHg外,无异常发现.心电图（ECG）及心脏彩超等均正常,诊断为高血压病。除仍服卡托普利外,于入院第2天开始服用氨氯地平5mg,每日1次。服药第 [Example 1] Male, 70 years old. Due to fatigue and weakness 4 months on June 20, 2000 treatment, history of previous hypertension, who have long been taking nifedipine, ankle edema and stop taking. Physical examination except for systolic blood pressure> 140mmHg, no abnormalities found. Electrocardiogram (ECG) and cardiac ultrasound were normal, diagnosed as hypertension. In addition to still taking captopril, taking amlodipine 5mg on day 2 of admission, once daily. Medication first