Long-acting anticholinesterase agents, echothiophate iodide (Phospholine Iodide, 217 MI) and demecarium bromide (Humorsol, BC 48), have been used with increasing frequency in the past few years for treatment of glaucoma.1-4
With the local use of longer acting anticholinesterase agents there is always the potential hazard of systemic reaction. Our attention was sharply focused on this problem when a patient with open-angle glaucoma being treated with echothiophate iodide was admitted to the hospital with severe, persistent diarrhea of undetermined etiology. Blood analysis revealed markedly depressed red cell and serum cholinesterase values. When the echothiophate iodide was discontinued, the symptoms disappeared and the blood cholinesterase values slowly returned toward the normal range.
This episode motivated investigation of other patients receiving echothiophate iodide therapy with the following objectives: (1) To correlate blood cholinesterase levels and dosage of echothiophate iodide with systemic complaints; (2) To determine if glaucoma patients not treated with echothiophate
HUMPHREYS JA, HOLMES JH. Systemic Effects Produced by Echothiophate Iodide in Treatment of Glaucoma. Arch Ophthalmol. 1963;69(6):737-743. doi:10.1001/archopht.1963.00960040743011