Merkle W
Klin Monbl Augenheilkd. 1981 Jan;178(1):50-4. doi: 10.1055/s-2008-1055293.
In 39 selected patients with open-angle glaucoma, in whom pressure regulation with Timolol alone was inadequate, success was achieved by using this drug in combination with various other glaucoma drugs over treatment periods of 12 to 18 months. In all cases, Timolol had had a significant, thought inadequate pressure-lowering effect; only by adding either 0.5%-2% pilocarpine. 0.75-2.25% carbachol, 2% aceclidine, 0.1% epinephrine or 250 mg of acetazolamide could IOP be lowered effectively to an acceptable level.