As I'm sure you know, it's always advisable to refrain from polypharmacy due to the adverse effect of drug interactions. However, if a patient requires treatment for different conditions in addition to antiepileptic drugs, relatively safe medications to consider for partial/focal (non-generalized) epilepsy include Keppra, Topamax, Neurontin (not as effective as an antiepileptic) and Zarontin. Topamax may have dual properties as it has been used for a number of psyche disorders (although many are off label) and is an effective seizure med. Unfortunately, many of these meds cause sedation and some like Keppra can cause behavioral changes. THe main point here though is that they don't interact with many other psyche drugs. Hope that helps, please contact your hospital's pharmacist and consider a formal n eurological consult for specific cases.