I never use drugs on my permanent companions. However, I do use them on myself and all temporary allies.
For instance, one simple method I devised of protecting Grisham's pasture is to simply give one cow 2 Buffout and 1 Psycho (Jet optional). Due to some flaw in the programming, giving one critter drugs on a map makes all critters of the same type get the effect (and the drawbacks if you wait a few hours).
This kind of breaks the game, but if you do it in certain ways, it can be amazingly funny. I used an elite fighting force of cows to slaughter a pack of wolves, for god's sake. The cows attacked 4 times a turn for over 10 damage sometimes, and took very little damage in return.
Using them on enemies can also make certain fights a piece of cake. Using 2 Jet and any amount of Buffout on one of Metzger's guards, then waiting about 6 hours, turns them all into sitting ducks with 1 AP.
