Addiction

A chronic neurologic and biologic disease defined by pain specialists and

characterized by behaviors that include one or more of the following: impaired control over drug use, compulsive use,

continued used despite harm, and craving to use the opioid for effects other than

pain relief

Adjuvant analgesic agent

A drug that has a primary indication other than pain (e.g., anticonvulsant,

antidepressant, sodium channel blocker, or muscle relaxant) but is an

analgesic agent for some painful conditions; sometimes referred to as

co-analgesic

Agonist-antagonist

A type of opioid (e.g., nalbuphine [Nubain] and butorphanol [Stadol]) that binds to

the kappa opioid receptor site acting as an agonist (capable of producing analgesia)

and simultaneously to the mu opioid receptor site acting as an antagonist

(reversing mu agonist effects)

Allodynia

Pain due to a stimulus that does not normally provoke pain, such as touch;

typically experienced in the skin around areas affected by nerve injury

and commonly seen with many neuropathic pain syndromes

Antagonist

Drug that competes with agonists for opioid receptor binding sites; can

displace agonists, thereby inhibiting their action

Breakthrough pain (BTP)

A transitory increase in pain that occurs on a background of otherwise

controlled persistent pain

Ceiling effect

An analgesic dose above which further dose increments produce no

change in effect

Central sensitization

A key central mechanism of neuropathic pain; the abnormal

hyperexcitability of central neurons in the spinal cord, which results from complex changes induced by the incoming barrages of nociceptors

Comfort-functioning goal

The pain rating identified by the individual patient above which the

patient experiences interference with function and quality of life (e.g.,

activities the patient needs or wishes to perform)

Efficacy

The extent to which a drug or another treatment “works” and can produce the effect in question – analgesia in

this context

Half-life

The time it takes for the plasma concentration (amount of drug in the body) to be reduced by 50% (After starting a drug, or increasing its dose, four to

five half-lives are required to approacha steady-state level in the blood, irrespective of the dose, dosing interval, or route of administration; after

four to five half-lives, a drug that has been discontinued generally is considered to be mostly

eliminated from the body.)

Hydrophilic

Readily absorbed in aqueous solution

Intraspinal

“within the spine”; refers to the spaces or potential spaces

surrounding the spinal cord into which medications can be

administered

Lipophilic

Readily absorbed in fatty tissues

Metabolite

The product of biochemical reactions during drug metabolism

Mu agonist

Any opioid that binds to the mu opioid receptor subtype and produces

analgesic effects (e.g., morphine): used interchangeably with the terms

full agonist, pure agonist, and morphinelike drug