<prompt> Which of the following does not cross the blood-brain barrier?PralidoximeObidoximeDiacetyl-monoximePhysostigmine  <response>: Ref: KD Tripathi pharmacology 7th edition page.no: 111 Katzung 11e p121 Pralidoxime has positively charged quaternary nitrogen. Quaernary molecules are heavy and cant penetrate the blood-brain barrier Pralidoxime or 2-PAM, usually as the chloride or iodide salts, belongs to a family of compounds called oximes that bind to organophosphate-inactivated acetylcholinesterase. It is used to treat organophosphate poisoning in conjunction with atropine and diazepam 