Effects of the topically applied calcium-channel blocker flunarizine on intraocular pressure in clinically normal dogs.
OBJECTIVE
To determine effects of the topically applied calcium-channel blocker flunarizine on intraocular pressure (IOP) in clinically normal dogs.


METHODS
20 dogs.


METHODS
Baseline diurnal IOPs were determined by use of a rebound tonometer on 2 consecutive days. Subsequently, 1 randomly chosen eye of each dog was treated topically twice daily for 5 days with 0.5% flunarizine. During this treatment period, diurnal IOPs were measured. In addition, pupillary diameter and mean arterial blood pressure (MAP) were evaluated. Serum flunarizine concentrations were measured on treatment day 5. Intraday fluctuation of IOP was analyzed by use of an ANOVA for repeated measures and a trend test. Changes in IOP from baseline values were assessed and compared with IOPs for the days of treatment. Values were also compared between treated and untreated eyes.


RESULTS
A significant intraday fluctuation in baseline IOP was detected, which was highest in the morning (mean +/- SE, 15.8 +/- 0.63 mm Hg) and lowest at night (12.9 +/- 0.61 mm Hg). After 2 days of treatment, there was a significant decrease in IOP from baseline values in treated (0.93 +/- 0.35 mm Hg) and untreated (0.95 +/- 0.34 mm Hg) eyes. There was no significant treatment effect on pupillary diameter or MAP. Flunarizine was detected in serum samples of all dogs (mean +/- SD, 3.89 +/- 6.36 microg/L).


CONCLUSIONS
Topically applied flunarizine decreased IOP in dogs after 2 days of twice-daily application. This calcium-channel blocker could be effective in the treatment of dogs with glaucoma.
Greller
Andrew L
AL
Eye Care for Animals, 2316 W Northern Ave, Phoenix, AZ 85021, USA.
Hoffman
Allison R
AR
Liu
Chengcheng
C
Ying
Gui-shuang
GS
Vudathala
Daljit K
DK
Acland
Gregory M
GM
Komáromy
András M
AM
D000287:Administration, Topical; D000818:Animals; D002121:Calcium Channel Blockers / Q000008:administration & dosage* / Q000494:pharmacology*; D004285:Dogs; D004334:Drug Administration Schedule; D005260:Female; D005444:Flunarizine / Q000008:administration & dosage* / Q000494:pharmacology*; D006262:Health; D007429:Intraocular Pressure / Q000187:drug effects*; D008297:Male; D013997:Time Factors
D002121:Calcium Channel Blockers; D005444:Flunarizine