The combination of guanethidine 1% and epinephrine 0.2% in one eye drop (GA-weak) in the treatment of glaucoma.

Thirty-one patients (58 eyes) with either primary open angle glaucoma (19 patients with 34 eyes) or suspected glaucoma (12 patients with 24 eyes) were treated for a period of 7 months with only guanethidine 1% and epinephrine 0.2% in one eyedrop (GA-weak) twice daily. The intraocular pressure (IOP) was controlled in 64% of all eyes with an average pressure decrease of 8.4 mm Hg or 31% (p < 0.005). Tonography revealed that the decrease in IOP was due both to inhibition of aqueous humour production (26%, p < 0.005) and to an increase in outflow facility (32%, p < 0.005), showing supersensitivity to inflow and outflow for epinephrine 0.2%, 8 patients were eliminated from the study due to tolerance for the drug. The side-effects were mild and did not lead to cessation of treatment. GA-weak was found to be an effective agent in the management of glaucoma. The treatment was well tolerated by the patients.