Acetazolamide is a carbonic anhydrase inhibitor. This enzyme catalyzes the reversible reaction involving the hydration of carbon-di-oxide and the dehydration of carbonic acid. In the eye, this inhibitory action of Acetazolamide decreases the secretion of aqueous humor and results in a drop in intraocular pressure, a reaction considered desirable in case of glaucoma. Inhibition of carbonic anhydrase in the central nervous system appears to retard abnormal paroxysmal and excessive discharge from central nervous system neurons. So, Acetazolamide is also used as an adjuvant in the treatment of epilepsy.