A prospective, long-term, randomized study of the efficacy and safety of the drug combination pilocarpine 1% with clonidine 0.06% or clonidine 0.125% versus timolol 0.25%.

The purpose of this prospective, randomized study was to evaluate the efficacy and safety of the drug combinations--pilocarpine 1% with clonidine 0.06% and pilocarpine 1% with clonidine 0.125%, in comparison with timolol 0.25%. 54 patients with bilateral primary open angle glaucoma and comparable IOP were assigned to three study groups: group 1 received the drug combination of pilocarpine 1% and clonidine 0.06%, group 2 received the drug combination pilocarpine 1% and clonidine 0.125% and group 3 only timolol 0.25% drops. In all groups twice-daily medication was used. Mean diurnal IOP as well as ocular and systemic side effects were evaluated at week 1, 2, 4, 8 and 12. Changes in blood pressure, pulse rate, pupil size and patient symptoms were also recorded. At three months all patients had completed the study. Diurnal IOP was significantly reduced from baseline in all groups and consistent IOP reduction was achieved in all three groups at all follow up periods. Mean IOP reduction was 18.40%, 28.45% and 24.64% in group 1, group 2 and group 3, respectively. Flattening of the diurnal fluctuation in IOP was also seen in all patients. On comparing the IOP reduction achieved amongst the three groups, there was a statistically significant difference between group 1 and group 2 as well as between group I and group 3 while the difference between group 2 and group 3 was statistically insignificant. The drug combinations of pilocarpine 1% and clonidine did not produce any statistically significant effect on pupil diameter. No statistically significant difference was noted with respect to patient symptoms, blood pressure and pulse rate. In conclusion, the drug combination of pilocarpine 1% and clonidine 0.125% produces IOP reduction comparable to that achieved with timolol 0.25% drops in twice daily dosage and does not result in any significant ocular and systemic adverse effects.