In the present study we evaluate the effects of two associated adrenergic drugs, Epinephrine-Metipranolol (0.3%) and Epinephrine-Dapiprazole, on the intraocular pressure and pupil diameter. Twenty patients affected by open angle glaucoma have been selected into two groups; in the first group, endocular pressure and pupil diameter have been evaluated at the baseline, after topical instillation of Epinephrine and after topical instillation of Metipranolol; in the second group the same parameters have been evaluated at the baseline, after topical instillation of Epinephrine and after topical instillation of Dapiprazole. The results show that no significant differences were observed on the intraocular pressure between the two different groups. A significant difference in the pupil diameter was observed after topical instillation of Epinephrine-Metipranolol but not after Epinephrine-Dapiprazole. Epinephrine-Dapiprazole reduces endocular pressure without to modify pupil diameter so that can also be used in patients with narrow angle.