"He's stable, but he still needs something to counteract what's in his system sooner rather than later." Geralt doesn't actually think it's 'poison', but it's an easy shorthand for 'recklessly drugged with enough shit to effectively act as an overdose or poison anyway'. That Waver is holding on well right now is good, and Geralt doesn't want to squander that by dragging their heels on getting him well. That's like daring fate to fuck with them.

Berserker doesn't strike him as someone who'd be actively concerned about Ygraine, so Geralt doesn't ask. He'll absolutely go back for her, but he needs to get a handle on this, first.

Once the two monsters have caught up - a little, he's not going to wait around forever, "Come on. There are halfway camps set up down here, we'll have to set him up in the first one we find."