Final answer:
β-blockers like timolol and betaxolol are used in glaucoma treatment to lower intraocular pressure by reducing aqueous humor production, binding to β-receptors in the eye. Their systemic absorption can result in cardiovascular and respiratory side effects.
Step-by-step explanation:
β-blockers are commonly used as glaucoma medications. These drugs, including commonly used ones like timolol, betaxolol, and levobunolol, work by reducing the production of aqueous humor in the eye, decreasing intraocular pressure which is critical in the treatment of glaucoma. β-blockers are sympatholytic drugs that bind to β-adrenergic receptors in various tissues, including the heart and eye. In the heart, they block adrenaline, which prevents vasoconstriction and cardioacceleration, thereby reducing blood pressure. For glaucoma, their mechanism involves blocking β-receptors in the ciliary body of the eye, resulting in reduced aqueous humor production. When considering the side effects of β-blockers, it's important to note that systemic absorption can lead to cardiovascular effects such as bradycardia, hypotension, and in some cases respiratory effects like bronchospasm, especially in patients with pre-existing conditions like asthma or chronic obstructive pulmonary disease (COPD).