A review of the clinical pharmacokinetics of pilocarpine, moxisylyte (thymoxamine), and dapiprazole in the reversal of diagnostic pupillary dilation.

An alpha-adrenergic blocking drug, dapiprazole, is now marketed in eyedrop form. Dapiprazole is being promoted as an agent suitable for reversing the diagnostic mydriasis produced by tropicamide or tropicamide and phenylephrine. The mechanism of action of dapiprazole is thought to be the same as that of moxisylyte (thymoxamine). The human pharmacokinetics for these drugs are reviewed and compared to pilocarpine. Published data indicate that either dapiprazole (0.5%) or moxisylyte (0.5%) enhance recovery from the mydriasis produced by tropicamide, phenylephrine, or their combination. However, because the published studies differ substantially in the doses of these mydriatics or in the miotics actually used, it is not possible to make any firm recommendations on how many drops of these new miotics should be instilled.