 7. Randomization and treatment: After stratification for centre, 500 eligible patients will be randomized into 2 groups. 250 will receive amlodipine 5 mg per day, and 250 will receive nifedipine GITS 30 mg per day. At 4 weeks of follow-up, the drug dosage per day may increase to 10 mg of amlodipine and 60 mg of nifedipine GITS, if blood pressure measured in doctors office cannot be controlled to a level below 14090 mm Hg. If there were no compelling indication, no other antihypertensive drug is allowed during the 2-month trial. 