Most drug interaction checkers won't list cocaine (used internally) so you may not find much good information there (since its medical indication is for topical use.)
Carisoprodol will likely help ameliorate the symptoms of a cocaine comedown. The main concern that I would think of with this combination would be seizure, as stimulants increase the chance of seizure and carisoprodol can lower the threshold for some types of seizures. Benzodiazepines are the best option, but carisoprodol (in a reasonable dose) should be fairly safe.