Priority 10 from the Epilepsy (Canada) PSP

UNCERTAINTY: What is the efficacy (i.e. the effectiveness of reducing seizures) of adding a second anti-seizure medication compared to changing to a different anti-seizure medication? How can we determine which combinations of anti-seizure drugs are effective? (JLA PSP Priority 10)
Overall ranking 10
JLA question ID 0110/10
Explanatory note When a person's seizures are not well-controlled by a single medication (monotherapy), physicians may decide to add a second medication (combination therapy or polytherapy) or switch to a different medication. In some cases, polytherapy may be more effective, depending on how each drug works in the brain and how they interact with each other. In other cases, a single, but different medication may be most effective. However, there are no clear guidelines for which approach to take, and studies directly comparing monotherapy with polytherapy are lacking. In addition, there is no single approach to treatment that works for all individuals, and a person's response to a given anti-seizure drug is generally unpredictable. Research in this area can help to uncover the most effective drug regimens for different types of epilespy, and how a person's unique biology can affect their response to treatment. 
Evidence

Panebianco, M., Bresnahan, R., Ramaratnam, S., & Marson, A. G. (2020). Lamotrigine add‐on therapy for drug‐resistant focal epilepsy. Cochrane Database of Systematic Reviews(3). doi:10.1002/14651858.CD001909.pub3
Health Research Classification System category  Neurological
Extra information provided by this PSP
Original uncertainty examples If I tell my dr that I feel slow, depressed and tired now when I'm taking 2 meds, why can't we lower the dose (or drop one completely) to see what happens? ~ Why do I have to take 2 meds now? If one stopped working, shouldn't I stop taking it when I started the new one?   ~ Is there any treatment other than medication? Why do neurologists put patients on multiple anti seizure medication as opposed to changing the medication to one that works keeping them on only one? ~ There should be just 1 medicine to take once a day because I also have memory problems with topiramate and I can't stop the fact that it has been going on for 4 years I have had a hard time but medications 2 times per day is too hard for me
Submitted by People with Seizures x 7, Friend or Family Member x 1
PSP information
PSP unique ID 0110
PSP name Epilepsy (Canada)
Total number of uncertainties identified by this PSP. 96  (To see a full list of all uncertainties identified, please see the detailed spreadsheet held on the JLA website)
Date of priority setting workshop 6th & 7th April 2021