Acetazolamide

Acetazolamide is a pharmaceutical used in the treatment of glaucoma, epilepsy, heart failure and other conditions. It can be taken orally or injected intravenously. It works by reducing the amount of hydrogen ions and bicarbonate in the body. 
Side effects include numbness, tinnitus, anorexia, vomiting and sleepiness. It is counter-indicated for people with kidney disease or liver disease. It also interacts with many other drugs.
Acetazolamide at Wikipedia