title: Effect of varying drop size on the efficacy and safety of a topical beta blocker.
abstract: We studied the effects on efficacy and safety of varying the drop size of a topical solution of levobunolol 0.5%. In a double-masked, crossover acute study, we administered a single drop of either 35 microL of vehicle, or 20, 35, or 50 microL of levobunolol one hour before the subjects began a ten-minute treadmill challenge electrocardiogram. After exercise the mean heart rate was 111 beats per minute (bpm) in the vehicle group and 102 to 103 bpm in the three levobunolol groups, which were significantly different from the control group but not from each other. In a randomized double-masked, parallel, chronic study, 117 patients with elevated intraocular pressure (IOP) instilled one of the three drop sizes of levobunolol twice daily for three months. Mean decreases in IOP ranged from 5.1 to 6.0 mmHg in the three groups, not significantly different from each other in mean IOP, heart rate, or blood pressure. We conclude that drop size in the range tested had no clinically significant effect on either efficacy or safety of a beta blocker such as levobunolol.
authors.affiliation: University of California, Irvine.
authors.forename: A D
authors.initials: AD
authors.lastname: Charap
authors.forename: D H
authors.initials: DH
authors.lastname: Shin
authors.forename: G
authors.initials: G
authors.lastname: Petursson
authors.forename: D
authors.initials: D
authors.lastname: Cinotti
authors.forename: E
authors.initials: E
authors.lastname: Wortham
authors.forename: R H
authors.initials: RH
authors.lastname: Brown
authors.forename: D E
authors.initials: DE
authors.lastname: Silverstone
authors.forename: J M
authors.initials: JM
authors.lastname: Atkins
authors.forename: C Y
authors.initials: CY
authors.lastname: Eto
authors.forename: J C
authors.initials: JC
authors.lastname: Lue
mesh_terms: D000287:Administration, Topical; D000328:Adult; D001794:Blood Pressure / Q000187:drug effects; D004304:Dosage Forms; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D004562:Electrocardiography; D005080:Exercise Test; D005500:Follow-Up Studies; D005902:Glaucoma, Open-Angle / Q000188:drug therapy*; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D007429:Intraocular Pressure / Q000187:drug effects*; D002040:Levobunolol / Q000008:administration & dosage* / Q000009:adverse effects / Q000627:therapeutic use; D008875:Middle Aged; D015337:Multicenter Studies as Topic; D011897:Random Allocation; D013997:Time Factors; D014792:Visual Acuity / Q000187:drug effects
chemical_list: D004304:Dosage Forms; D002040:Levobunolol