毒药是poison，解药是？

antidote

新牛津英汉双解大词典
antidote
noun
a medicine taken or given to counteract a particular poison
解毒药，解毒剂
something that counteracts or neutralizes an unpleasant feeling or situation
矫正方法，对抗手段
laughter is a good antidote to stress.
笑是对抗压力的良方。