Unless they are all in a particular class (functional group) of compounds, a different enzyme (or other reaction would be needed for each pharmaceutical. Further, the existence of such compounds does not necessarily mean that they would be inexpensive, easy to process (especially in mixed streams) or wouldn’t themselves result in further polluting effluents.
From you description of the situation I’d say that there is a much more serious protocol issue if excess, out-of-date, or used products are just “flushed” be the staff! That does not sound like appropriate active biologics disposal in ANY civilized jurisdiction. Remember that “Sustainability” is all about first REPLACING harmful materials when possible, THEN Reducing their usage, and only finally Recycling or repurposing them into other useful products. We really don’t want to create, much less encourage and environment or process where we just assume whatever “waste” will somehow be “treated” The GOAL is to ELIMINATE the waste in the first place.
Succeeding in proper application and use will go a long way in eliminating any need for remedial action.