Oxybutynin

Oxybutynin is a pharmaceutical that prevents the action of acetycholine receptors. It is commonly used for bladder difficulties including spasm, incontinence and kidney stones.
Typical side effects are dry mouth, constipation, blurred vision, drowsiness and dizziness. About half of patients discontinue using the drug within six months because of these side effects, particularly dry mouth. 
Oxybutynin at WikipediaCategory:Pharmaceuticals