Comparison of aqueous and gellan ophthalmic timolol with placebo on the 24-hour heart rate response in patients on treatment for glaucoma.
OBJECTIVE
Topical beta-blocker treatment is routine therapy in the management of patients with glaucoma. Therapy results in systemic absorption, however, the degree of reduction of resting and peak heart rate has not been quantified.


METHODS
This trial evaluated the effect of placebo, 0.5% aqueous timolol (timolol solution) and a 0.5% timolol suspension that forms a gel on application to the conjunctiva (timolol gellan) on the 24-hour heart rate in patients currently being treated for glaucoma to quantify the reduction in mean heart rate.


METHODS
Forty-three Caucasian patients with primary open-angle glaucoma or ocular hypertension with a mean (+/-SD) age of 63 (+/-8) years were randomized and crossed over in a double-masked manner to 14 days of treatment with placebo (morning and evening in both eyes), timolol solution (morning and evening in both eyes), or timolol gellan (morning in both eyes with placebo in the evening). On the 13th day of each period, heart rate was recorded continuously during a typical, ambulant 24-hour period.


RESULTS
Both timolol solution and timolol gellan reduced the mean 24-hour heart rate compared with placebo (P < or = .001), and this reduction was most pronounced during the daytime (-7.5% change in mean heart rate, -5.7 beats/min). Timolol gellan showed a numerically but not significantly smaller reduction in 24-hour heart rate, compared with timolol solution. During the night, the mean 12-hour heart rate on placebo and timolol gellan were both significantly less than on timolol solution; the difference between solution and gellan treatments was statistically significant (P = .01).


CONCLUSIONS
Both timolol solution and timolol gellan decrease the mean 24-hour heart rate compared with placebo. This response was most pronounced during the active daytime period. These data quantify the modest bradycardia associated with ophthalmic beta-blocker therapy in a typical patient population on therapy for glaucoma. Although exercise performance was not assessed in this trial, reductions of this magnitude should not have substantial clinical consequences.
Dickstein
K
K
Cardiology Division, Central Hospital in Rogaland, Stavanger, Norway. trout@online.no
Hapnes
R
R
Aarsland
T
T
D000319:Adrenergic beta-Antagonists / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D002940:Circadian Rhythm / Q000187:drug effects; D018592:Cross-Over Studies; D004311:Double-Blind Method; D005260:Female; D005782:Gels; D005902:Glaucoma, Open-Angle / Q000188:drug therapy*; D006339:Heart Rate / Q000187:drug effects*; D006801:Humans; D007429:Intraocular Pressure / Q000187:drug effects; D008297:Male; D008875:Middle Aged; D009798:Ocular Hypertension / Q000188:drug therapy; D009883:Ophthalmic Solutions; D012449:Safety; D013999:Timolol / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*
D000319:Adrenergic beta-Antagonists; D005782:Gels; D009883:Ophthalmic Solutions; D013999:Timolol