Sentence: An angiotensin 2 type 1 receptor blocker , olmesartan , and a calcium channel blocker , azelnidipine , possess not only an antihypertensive effect but also an antioxidative effect and other beneficial effects .
Drug combination annotation:
[{'class': 'POS', 'spans': ['olmesartan', 'azelnidipine'], 'is_context_needed': False}]