I was reading recently about environmental remediation being done, using an esterase to break down / neutralize cocaine that had contaminated waterways in Europe. Are there similar enzymes that can be used to safely break down pharmaceutical drugs, like surplus SSRIs and neuroleptics, that medical staff might otherwise just flush down the toilet thus causing more pollution? A way to neutralize them into safe inert ingredients first would seem beneficial to educate people about.
One of the great properties of enzymes is their specificity. Even broadly specific enzymes such as lipases and proteases are picky compared to, say, a general base catalyst. As a result, if you are interested in degrading a single specific compound (cocaine in your example), it is very likely that you can find or engineer an enzyme to do the job. But if you want to degrade a wide variety of compounds with different structures, you will need a diverse set of enzymes, each specific for one or a few of the compounds.