The aim of this study was to determine whether the magnitude of the intraocular pressure (IOP) lowering response in monkeys to the non-selective prostaglandin (PG)F2a-isopropyl ester (ie) can be reproduced by combining other PG subtype-selective compounds. IOP was lowered by approximately 25% after four to five days of topical administration with latanoprost (FP agonist, 1.5μg, q.d.), bimatoprost (prostamide, whose metabolites have been shown to be FP agonists; 9μg, q.d.), or travoprost (FP agonist, 1.2μg, q.d) or the EP2 agonist butaprost (25μg, b.i.d.). The EP1 agonist, 17-phenyl trinor(PhT)PGE2 b.i.d. and EP3 agonist, sulprostone b.i.d. had no IOP lowering effects. The addition of butaprost, sulprostone (10μg), or 17PhTPGE2 (25μg) to latanoprost did not lower IOP more than latanoprost alone. However, treatment with the combination of latanoprost, 17PhTPGE2, butaprost, and sulprostone produced a similar 50-55% reduction in IOP as did PGF2α-ie (b.i.d.). In conclusion, latanoprost, travoprost and bimatoprost produce similar IOP-lowering responses in normotensive monkeys and are most efficacious when administered q.d. pm compared to b.i.d. The combination of the FP, EP1, EP2, and EP3 agonists used in this study was sufficient to lower IOP by the same magnitude as PGF2α-ie suggesting combining PG-subtype agonists may be a potent anti-glaucoma strategy.

H-7 can enhance OF in the presence of trabecular obstruction produced by long-term ECHO treatment. This suggests that H-7 may be useful in treating glaucoma, even in the presence of accumulated plaque material that has been described previously.