Provided are compositions comprising a cocaine esterase (CocE) and a compound that thermostabilizes the CocE. Also provided are methods of thermostabilizing a cocaine esterase. Additionally provided are methods of treating a mammal undergoing a cocaine-induced condition. Methods of determining whether a compound is a thermostabilizing agent for a protein are also provided. Uses of the above-described compositions for the treatment of a cocaine-induced condition is additionally provided. Additionally provided is an isolated nucleic acid encoding a CocE polypeptide having the substitutions L169K and G173Q, and the CocE polypeptide encoded by that nucleic acid, and pharmaceutical compositions thereof. Further provided is the use of that composition for the manufacture of a medicament for the treatment of a cocaine-induced condition and for the treatment of a cocaine-induced condition.