prescription
noun
°The act of prescribing a rule, law, etc..
°(medicine) A written order, as by a physician, for the administration of a medicine or other intervention. See also scrip.
"The surgeon wrote a prescription for a pain killer and physical therapy."
adjective
°(of a drug, etc.) only available with a physician's written prescription.
"Many powerful pain killers are prescription drugs in the U.S."