[Comparison of the effects of carteolol and metipranolol eyedrops on the ventilatory and cardiovascular functions in asthmatics].

Systemic effects of two topical B adrenergic blocking agents, carteolol and metipranolol, recently introduced in the treatment of open angle chronic glaucoma, were investigated in two groups of 10 asthmatic patients, according to a controlled trial device. Saline eye drops as placebo, then, 30 mn later beta blocker eye-drops, were instillated at usual dose. Heart rate, systolic and diastolic blood pressure, vital capacity (VC) and expiratory outflow (FEV1), were checked every 15 mn during 90 mn. They did not vary under placebo. After carteolol and metipranolol, heart rate decreased more than 10% in 7 out of 10 patients in each group (extreme individual changes: -16.7 and -25.0%). Bradycardia was always sino atrial. FEV1 was lowered in 3 patients with carteolol and in 6 with metipranolol (extreme individual values: -32.3 and -31.8%). If time is not taken in consideration, the lowest values were -8.6 +/-4.6% with carteolol and -17.9 +/- 3.3% with metipranolol. CV was reduced only in 1 patient under carteolol and 2 patients under metipranolol. Systemic blood pressure remained unchanged. 7 patients complained of ocular pain when metipranolol was instillated. Comparison of both ocular topics shows that metipranolol lowers heart rate and FEV1 more than carteolol, which has a sympathomimetic intrinsic activity. These two drugs have the same clinical efficiency. Our results point out the risks outcoming from their systemic diffusion, and the absolute necessity to comply with the general rules of good use of beta blockers, even with eye drops, mainly the contra-indications and the strict adjustment of individual doses.