It's almost certainly modafinil, a dextroamphetamine like dexedrine, and galantamine.
The first two are commonly used/abused in DC and showed up often on the white house pharmacy report. The third is an acetylcholinesterase inhibitor can be effective in treating some of the effects of dementia, and is especially effective at inhibiting AChE when used occasionally, occasionally being abused by weirdoes who want to lucid dream. (HOLY SHIT, DO NOT DO THIS) He's almost certainly on memantine or memantine/donepezil combo therapy, and occasionally jamming the gas on the AChE inhibitors is very plausibly effective in boosting short term cognition.
Then they hide him away for a few days while he basically openly flows from both ends of his digestive system. (This is especially why you shouldn't abuse galantamine, you will shit the bed and if you're also using sleeping drugs, you can aspirate vomit and dry drown in your own barf while sleeping.)