The Sound of Evolution
Timolol
Mechanism of action:
Timolol is a non-selective beta-adrenergic blocker. Timolol blocks beta2 receptors in the ciliary epithelium of the eye, reducing cAMP production and decreasing aqueous humor secretion. It also blocks beta1 receptors in the myocardium, leading to a reduced heart rate, decreased myocardial contractility, and lower cardiac output. Blockade of beta2 receptors in bronchial and vascular smooth muscle can also cause smooth muscle contraction.
Reference(s):
1. Nieminen T et al. (2007). Ophthalmic timolol: plasma concentration and systemic cardiopulmonary effects. Scand J Clin Lab Invest.
2. Dunn FG et al. (1981). Pharmacokinetics, mechanisms of action, indications, and adverse effects of timolol maleate, a nonselective beta-adrenoreceptor blocking agent. Pharmacotherapy.
3. Obel AO et al. (1983). A comparison of timolol plus hydrochlorothiazide plus amiloride and methyldopa in essential hypertension in Black Africans. Trop Geogr Med.