Scopolamine

I had been shot full of dope to keep me quiet. Perhaps scopolamine too, to make me talk.

The Incas had herbs for headaches and other pains; and they used scopolamine, a poison from the datura plant, as an anaesthetic.

Scopolamine is a nonselective muscarinic acetylcholine receptor (mAChR) antagonist with potentially selective inhibitory actions on muscarinic subtypes 1 and 2 (M1 and M2). Unlike ketamine, esketamine, and nitrous oxide, scopolamine directly affects the cholinergic pathway but does not directly modulate the glutamatergic pathway.