Pain Medication and Opiate Addiction

Abstract

Pain is a highly unpleasant and aversive human emotion. While it is elicited from stimulation of peripheral receptors via the spinothalamic tract to the thalamus in the brain, “top-down”: modulation from the cortex originating in social cues, self-confidence and such factors are also important in pain experience and behavior. The most potent pain medications are the opiates that stimulate several types of opiate receptor in the thalamus and elsewhere. The endogenous ligands of these receptors, enkephalins, are important neurotransmitters that are chemically short peptides. Opiates are highly effective in acute pain but come with a high potential for tolerance and addiction and are rarely indicated in chronic pain. Treatment of opiate addiction may involve maintenance with a partial agonist such as methadone or buprenorphine to substitute for abused opiates while blocking use of nonprescribed additional opiates. Opiate abuse side effects include overdose coma and death due to respiratory depression, and naloxone or naltrexone opiate antagonists able to reverse overdose should be available to first responders as well as to psychiatrists.