Suggestion, encapsulate a couple of sleeping pills in colorful capsules then offer the suspect those as ‘uppers’ or ‘meth’ and a glass of tea you say is booze. After they doze off, take ‘em in and let ‘em sleep it off.
Sounds good to me.
I assure you that paranoid delirium patients are not open for medications. And no one is stupid enough to give medication to someone whose previous medication ingestion is unknown.