Elevated intraocular pressure diseases such as glaucoma are treated with compounds represented by formula I ##STR1## or a pharmaceutically acceptable acid addition salt thereof, wherein R.sub.1 is alkyl of two to four carbon atoms; and R.sub.2 is alkyl of three or four carbon atoms; or R.sub.1 and R.sub.2 taken together with N form ##STR2## wherein n is 0, 1, or 2 and R.sub.5 and R.sub.6 are each independently lower alkyl or hydro; R.sub.3 is hydro or hydroxy; R.sub.4 is hydro, lower alkyl, amino, or lower alkylamino.
高眼压疾病如青光眼可用由以下式表示的化合物治疗:##STR1## 或其药学上可接受的酸盐,其中 R.sub.1 是碳原子数为二至四的烷基;R.sub.2 是碳原子数为三或四的烷基;或者 R.sub.1 和 R.sub.2 与 N 一起形成 ##STR2##,其中 n 为0、1或2,R.sub.5 和 R.sub.6 各自独立为较低的烷基或羟基;R.sub.3 为羟基或羟基基;R.sub.4 为羟基、较低的烷基、
氨基或较低的烷基
氨基。