41 下列降血壓藥物，何者可用作降眼壓藥物？
(A) Nifedipine
(B) Enalapril
(C) Timolol
(D) Prazosin

In its oral form, it is used:

• to treat high blood pressure
• to prevent heart attacks
• to prevent migraine headaches^[2]

In its ophthalmic form it is used to treat open-angle and occasionally secondaryglaucoma by reducing aqueous humour production through blockage of the beta receptors on the ciliary epithelium. The pharmacological mechanism by which it actually does this is still unknown. First beta-blocker approved for topical use in treatment of glaucoma in the USA (1978). With monotherapy, depresses IOP 18-34% below baseline within first few treatments.

非選擇性β阻斷藥

Timolol 降低眼內壓，治青光眼。

（有氣喘不能用）