As tolerance to phenobarbital develops, the amount needed to maintain the same level of intoxication increases;tolerance to a fatal dosage, however, does not increase more than two-fold.

• 随着苯巴比妥耐药性的增强，保持相同宿醉状态所需的药量也随之增加，但是，对致死剂量耐受性的增加却不会超过两倍。