Aqueous flow is reduced by the alpha-adrenergic agonist, apraclonidine hydrochloride (ALO 2145)

Ophthalmology. 1988 Sep;95(9):1217-20. doi: 10.1016/s0161-6420(88)33038-1.


Apraclonidine hydrochloride (ALO 2145), a clonidine derivative that does not cross the blood-brain barrier, was applied topically to one eye of each of 20 normal human subjects. The rate of aqueous humor flow and the permeability of the blood-aqueous barrier were measured by fluorophotometry. Four hours after administration, the flow rate in the apraclonidine-treated eyes was 35% lower than that measured in the control eyes. Three hours after instillation, the intraocular pressure (IOP) was 34% lower in the apraclonidine-treated eyes when compared with control eyes. Both these differences were statistically significant. The drug had little, if any, effect on blood-aqueous permeability.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Administration, Topical
  • Adult
  • Aqueous Humor / drug effects*
  • Aqueous Humor / metabolism
  • Clonidine / administration & dosage
  • Clonidine / analogs & derivatives*
  • Clonidine / pharmacokinetics
  • Clonidine / pharmacology
  • Double-Blind Method
  • Female
  • Humans
  • Intraocular Pressure / drug effects*
  • Male
  • Ophthalmic Solutions
  • Permeability
  • Placebos


  • Ophthalmic Solutions
  • Placebos
  • apraclonidine
  • Clonidine