Table 1 Definition of terminology

Misuse

Taking a prescription for a reason or at a dose or frequency other than for which it was prescribed; this may or may not reflect POUD*.

Use of a medication for nonmedical use, or for reasons other than prescribed. For example, altering dosing or sharing medicines, which has harmful or potentially harmful consequences. It does not refer to use for mind-altering purposes [9].

Abuse

Misuse with consequences. The use of a substance to modify or control mood or state of mind in a manner that is illegal or harmful to oneself or others. Potentially harmful consequences include accidents or injuries, blackouts, legal problems, and sexual behavior that increases the risk of human immunodeficiency virus infection [9].

Physical dependence

A state of adaptation manifested by a drug class-specific withdrawal syndrome that can be produced by abrupt cessation, rapid dose reduction, decreasing blood level of the drug, and/or administration of an antagonist [10].

Tolerance

A state of adaptation in which exposure to a drug induces changes that result in a diminution of one or more opioid effects over time [10].

Addiction

A primary, chronic, neurobiologic disease with genetic, psychosocial, and environmental factors influencing its development and manifestations. It is characterized by behaviors that include one or more of the following: impaired control over drug use, compulsive use, continued use despite harm, and craving [10].

Pseudo-addiction

An iatrogenic syndrome of “addiction-like” behaviors in which the patient seeks opioids to relieve pain—such as seeking different doctors, self-adjusting the opioid dose, early refills of opioids, etc.—rather than to achieve pleasure or other nonpain-related effect [11]. At times mistaken for true addiction, these behaviors tend to resolve and function improves once analgesia is better addressed. Further defined as “behavioral changes in patients that seem similar to those in patients with opioid dependence or addiction but are secondary to inadequate pain control” [12].

Therapeutic dependence

Drug-seeking secondary to anxiety about having an adequate supply of medication [13].

Opioid-induced hyperalgesia

A state of nociceptive sensitization caused by exposure to opioids. The condition is characterized by a paradoxical response, whereby a patient receiving opioids for the treatment of pain could actually become more sensitive to certain painful stimuli. The type of pain experienced might be the same as the underlying pain or might be different from the original underlying pain [14, 15].

Aberrant drug-related behavior

Taking a controlled substance medication in a manner that is not prescribed; causes for this may include:

• lack of understanding about how to take the opioid appropriately

• external pressures, such as to give to another person for his or her pain

• chemical coping

• pseudoaddiction (see below), including:

– physical tolerance and resultant inadequate pain control

– opioid-resistant pain

– opioid-induced hyperalgesia

– progression of their pain generator or disease

• addiction or substance use disorder (such as POUD)

• diversion

A behavior outside the boundaries of the agreed-on treatment plan which is established as early as possible in the doctor-patient relationship [16].