Solutions of levoepinephrine borate were prepared in concentrations of 0.06%, 0.12%, 0.25%, 0.50%, 1.00%, and 2.00%. These solutions were applied to the right eye only for four to six weeks in a series of open-angle glaucomatous patients who were receiving 4% pilocarpine to both eyes. Although a small effect was noted with lower doses, no meaningful additional hypotensive response from epinephrine was noted until the concentration reached 0.50%. The maximal additive response occurred with 2.00% levoepinephrine. Although the combined effect of pilocarpine and epinephrine was greater than the maximal effect of either drug alone, it was less than the additive effects of both drugs. Parallelism of the epinephrine and pilocarpine/epinephrine dose-response curves suggests that both drugs act by similar mechanisms.
Harris LS, Mittag TW, Galin MA. Aqueous Dynamics of Pilocarpine-Treated EyesThe Influence of Topically Applied Epinephrine. Arch Ophthalmol. 1971;86(1):1-4. doi:10.1001/archopht.1971.01000010003001