Indication: Caffeine can excite the central nervous system and it can make the cerebral cortex more excited. And it can excite the medulla oblongata and promote the dilatation of the blood vessel. It can be used in the inhibition of the nerve. It can accelerate the contraction of the striated muscle, promote the dilatation of the circulation system and the blood vessel and the contraction of the cardiac muscle. It is good for the weakness of the cardiac muscle and the inhibition of the breath. It can acts on kidney as a diuretic.