Charley Horse; Cramps; Muscle cramp 

Quinamm; Quiphile 

Involuntary, painful shortening of muscles. Usually, a knotting of the muscles is visible.

Quinine, C20H24N2O2,is a natural white crystalline alkaloid having antipyretic, anti-malarial and analgesic properties and a bitter taste. It is a stereoisomer of quinidine.

Muscle Cramps as related to Quinine