Effects of D-timolol on intraocular pressure, heart rate, cardiac contractility, and tracheal muscle function.
Introduction of L-timolol maleate into the clinics for glaucoma treatment has been a great success as it produces relatively few side effects, such as miosis, ciliary spasm and headache, which are associated with the use of pilocarpine. Recent reports indicated, however, that L-timolol produces asthmatic attacks, cardiovascular suppression and central depression. D-Timolol was found to be as effective as L-timolol in lowering the intraocular pressure and aqueous humor production. However it was much less potent than L-timolol in inhibiting cardiac contractility and heart rate stimulated by isoproterenol and was less active in blocking beta-adrenergic receptors in tracheal muscle. It is suggested that the D-isomer of timolol could be used to treat glaucoma instead of L-isomer without producing untoward side effects in cardiovascular and bronchial tissues.
D000818:Animals; D003864:Depression, Chemical; D005260:Female; D006168:Guinea Pigs; D006339:Heart Rate / Q000187:drug effects; D006439:Hemodynamics / Q000187:drug effects*; D007429:Intraocular Pressure / Q000187:drug effects*; D007536:Isomerism; D009200:Myocardial Contraction / Q000187:drug effects; D011412:Propanolamines / Q000494:pharmacology*; D011817:Rabbits; D013999:Timolol / Q000494:pharmacology*; D014132:Trachea / Q000187:drug effects
D011412:Propanolamines; D013999:Timolol