Atenolol Versus Propranolol a Comparison of Ocular Hypotensive Effect of an Oral Dose

Br J Ophthalmol: first published as 10.1136/bjo.60.11.789 on 1 November 1976. Downloaded from

Brit. 7. Ophthal. (1976) 6o, 789

Atenolol versus propranolol A comparison of ocular hypotensive effect of an oral dose

MARGARET J. MACDONALD, PATRICIA M. CULLEN AND CALBERT I. PHILLIPS From the Department of Ophthalmology, University of Edinburgh, and Princess Alexandra Eye Pavilion, Edinburgh

Both atenolol and propranolol by mouth reduce Table I Details of patients ocular tension in normal and glaucomatous eyes (Phillips, Howitt, and Rowlands, i967; Elliot, Patient Sex Age Diagnosis Previous treatment Cullen, and Phillips, 1975; Wettrell and Pandolfi, (years) 1975). These drugs are f-adrenergic blockers but I Male 66 Open-angle glaucoma Pilocarpine propranolol affects both and well 2 Male 65 Chronic closed-angle Peripheral P1 32 receptors (as glaucoma iridectomy as having a 'membrane' effect), while atenolol is pilocarpine a more specific 31 receptor antagonist and lacks 3 Female 48 Open-angle glaucoma Pilocarpine di- chlorphenamide the membrane-stabilizing activity of propranolol. 4 Female 70 Open-angle glaucoma Pilocarpine 5 Male 62 Open-angle glaucoma Cyclodialysis copyright. (aphakic) pilocarpine 6 Male 52 Chronic closed-angle Sector iridectomy Aims glaucoma pilocarpine 7 Male 62 Ocular hypertension Nil The aim of this study was to compare the ocular 8 Male 62 Open-angle glaucoma Trephine hypotensive actions of single oral equipotent doses pilocarpine adrenaline of atenolol (50 mg) and propranolol (40 mg) in a 9 Male 67 Chronic closed-angle Iris inclusion double-blind cross-over study on io patients. glaucoma lo Female 68 Open-angle glaucoma Pilocarpine Selection of patients http://bjo.bmj.com/ The io individuals were chosen from patients randomly selected for examination, the blood pressure attending glaucoma clinics; they comprised six and pulse rate were measured and either 50 mg of atenolol with open-angle glaucoma, three with chronic or 40 mg of propranolol was given by mouth. The closed-angle glaucoma, and one with ocular hyper- observers were unaware of which treatment was given tension. They all satisfied previously-established and the order of administration was randomized. The same three properties were measured at hourly intervals criteria regarding age and general health-namely, for seven hours thereafter, by the same examiners. The on September 28, 2021 by guest. Protected they were aged 70 years or less and had no evidence same procedure was carried out on the second test day of cardiorespiratory disease or diabetes, and had with cross-over of the drugs; five patients (at random) normal renal function. Only one eye from each had atenolol first and propranolol second, while the patient, chosen at random, was included in the other five had the drugs in the reverse order. study. Details of the patients including previous treat- Results ment to the eye examined are given in Table I. OCULAR TENSION Methods In all IO patients ocular tension fell after both atenolol and propranolol. For both treatments a Conditions were standardized as far as possible. Local significant reduction in mean tensions occurred treatment to the eye to be examined and systemic two hours after administration and was maintained carbonic anhydrase inhibitors were stopped 24 hours after seven hours. However, at all times the mean before test days. Patients attended as outpatients between fall in ocular tension was greater during treatment g.o a.m. and 4 p.m. with at least a week between test days. After initial applanation tonometry on the eye with atenolol compared with propranolol, and with the exception of the sixth-hourly reading, these Address for reprints: Dr M. J. Macdonald, The Eye Pavilion, differences were statistically significant, whether Chalmers Street, Edinburgh EH3 9HA or not allowance was made for the slightly different Br J Ophthalmol: first published as 10.1136/bjo.60.11.789 on 1 November 1976. Downloaded from

790 British Yournal of Ophthalmology

Table II Comparison of ocular hypotensive effects of atenolol and propranolol based on adjusted mean intraocular pressure in io patients Hours after treatment

0 I 2 3 4 5 6 7 Propranolol Means 27-2 26.3 20-7 20-I I8.3 i6.7 I8-2 I9-6 Adjusted Means 25-8 20-2 201I i8-o i6-6 I8z2 I9-7 Atenolol Means 25-3 22-I I6.7 I70 Is-5 I4.7 15.9 I6.7 Adjusted Means 22-6 17.2 I7.0 15-8 14.8 I5.9 i6-6 Difference between adjusted means 3-2 3-0 3.1 2-2 Ix8 2.3 3.1

SE of difference o8o I-I2 0 70 0-72 0 74 I20 o-88

Significance (P)

in the papers already mentioned. It would be pressure is confirmed, a [n-blocking drug suitable biologically consistent if adrenergic stimulation for local administration may become available in increased outflow commensurately with increased clinical management of glaucoma. inflow to maintain a steady state. Route of administration may therefore be important local applica- Summary tion affecting outflow and systemic application inflow. Although we suspect that 5-blockers In a controlled double-blind cross-over trial in io given systemically reduce production of aqueous patients comprising six with open-angle glaucoma, humour, the efficacy of propranolol (as well as three with closed-angle glaucoma, and one with practolol) in the form of eye drops (Vale and ocular hypertension, a single oral dose of atenolol Phillips, I973) suggests that an improvement in (50 mg) was significantly more effective than outflow may also take place. It will be interesting propranolol (40 mg) in reducing ocular tension. to observe the effect of atenolol eye drops when We are grateful to ICI (Pharmaceuticals) Ltd, for they become available, not only for theoretical supplies of atenolol (Tenormin ICI) and propranolol, reasons but also because, if the expected fall in and to Dr A. Rushton for information and discussion.

References ELLIOT, M. J., CULLEN, P. M., and PHILLIPS, C. I. (I975) Brit. J. Ophthal., 59, 296 PHILLIPS, C. I., HOWITT, G., and ROWLANDS, D. J. (I967) Ibid., 51, 222 VALE, j., and PHILLIPS, C. I. (1970) Exp. Eye Res., 9, 902 , and (I973) Brit. J. Ophthal., 57, 210 WETTRELL, K., and PANDOLFI, M. (1975) Exp. Eye Res., 21, 45I copyright. http://bjo.bmj.com/ on September 28, 2021 by guest. Protected