Ocular hypotensive actions of haloperidol, a dopaminergic antagonist

Haloperidol, a dopaminergic antagonist, was found to be very effective in suppressing the intraocular pressure recovery curve of rabbits infused with 20% saline intravenously. Haloperidol was at least equipotent, if not more potent, in lowering IOP and had much longer duration of action compared with timolol maleate. In the cat model, haloperidol increased aqueous humor (AH) outflow initially, followed by a long-lasting suppression of AH formation. Since haloperidol does not block beta-adrenergic receptors and the ophthalmic dose required to lower IOP is only 6.5% of the antipsychotic dose, haloperidol might be a good drug for glaucoma treatment with the possibility of minimal side effects.