Appendix A. Key terms and definitions

Legal definitions of drugs of dependence and drugs of addiction vary between states/territories. Refer to RACGP’s Prescribing drugs of dependence in general practice, Part A – Clinical governance framework.

This guide uses the following definitions:

Drugs of addiction refer to all Schedule 8 (S8) drugs. These have strict legislative controls regarding their manufacture, supply, distribution, possession and use to reduce abuse, misuse, and physical and psychological dependence. Examples of S8 drugs include morphine, oxycodone, dexamphetamine, flunitrazepam (Rohypnol) and, as of February 2014, alprazolam.*

Drugs of dependence describe all S8 drugs plus specified Schedule 4 (S4) drugs that are subject to misuse, abuse and trafficking. All S4 drugs are restricted substances, but only some (eg benzodiazepines) can form dependence (these are called S4D drugs in New South Wales). Some others drugs, like anabolic steroids and amphetamines, are restricted and can only be prescribed by authority.

Each state and territory has its own legislative requirements. Refer to RACGP’s Prescribing drugs of dependence in general practice, Part A – Clinical governance framework.

_{*Xanax (Pfizer) has been withdrawn from the Australian market, however generic alprazolam is still currently available}

The two commonly used classification systems for data collection are the International Statistical Classification of Diseases and Related Health Problems, 10th revision, (ICD-10) and the Diagnostic and Statistical Manual of Mental Disorders, 5th edition, (DSM-5). Some of the terminology adapts poorly to the situation where prescription drugs are used to treat conditions, such as chronic non-malignant pain. 

Tolerance is a decrease in response to a drug dose. It occurs with all chronically used drugs of dependence, including opioids and benzodiazepines. Increased doses are required to achieve the effects originally produced by lower doses.³¹

Dependence, in strict pharmacological terms, is a state that develops during chronic drug treatment in which drug cessation elicits an abstinence reaction (withdrawal).

Dependence can be associated associated with a whole range of psychoactive drugs or chemicals (eg caffeine, alcohol, opioid, cannabis or stimulant dependence). As awareness of problematic drug use grew, the definition of dependence changed to include addiction and abuse. Various definitions of dependence evolved with DSM-4, ICD-10, World Health Organization (WHO) and leading authors describing it as a cluster of behavioural, cognitive and physiological phenomena that may develop after repeated substance use. Now people link dependence with ‘addiction’ when in fact dependence can be a normal body response to a substance. While drug dependence can be part of addiction, is not the same thing.

To reduce confusion, the new DSM-5 (2013) criteria has replaced drug dependence with DSM-5 substance use disorder measured on a continuum from mild to severe. Refer to Appendix A.3 Misuse, non-medical use and abuse..

Note: There are legal implications involving the term dependence (eg restrictions around prescribing to drug-dependent persons). Characteristics of person who is drug dependent include having a history of substance misuse and being identified as a ‘doctor shopper’ or ‘prescription shopper’.202 Refer to Appendix A.4, Drug-seeking behaviour.

Substance use disorder has been introduced in DSM-540 to replace dependence (or dependence syndrome) as used to refer to complex symptoms beyond tolerance and withdrawal. The essential feature of SUD is a cluster of cognitive, behavioral and physiological symptoms indicating the individual continues using the substance despite significant substance-related problems.40 Diagnosis of SUD requires the presence of at least two of 11 criteria, across four categories: impaired control, social impairment, risky use and pharmacology.

Note: In DSM-5, substance dependence and substance abuse have been combined into a single category of SUDs (eg ‘benzodiazepines dependence’ would be included within sedative, hypnotic, or anxiolytic use disorder).40 Each SUD is divided into mild, moderate and severe subtypes, with the number of criteria present determining the severity. (Refer to Table 3 for DSM-5 criteria and Table A.1 for ICD-10 criteria.)

Withdrawal or withdrawal syndrome is a group of symptoms of variable clustering and degree of severity which occur on cessation or reduction of use of a psychoactive substance that has been taken repeatedly, usually for a prolonged period and/or in high doses. Signs of physiological disturbance may accompany the syndrome. A withdrawal syndrome is one of the indicators of a dependence syndrome.³¹

Misuse refers to use of a substance for a purpose that is not consistent with legal or medical guidelines, and includes the non-medical use of prescription medication. Patients may inadvertently misuse prescription medication by taking them as prescribed but in response to inappropriate prescribing practices. Patients may deliberately misuse medication for non-medical purposes.³¹

Non-medical use describes use of a prescription drug, whether obtained by prescription or otherwise, for any purposes other than in the manner or for the time period prescribed, or by a person for whom the drug was not prescribed (ie diversion). Non-medical use occurs for a variety of reasons such as enjoyment of effects (especially when binge dosed), to enhance the effects of other drugs (eg benzodiazepines taken with opiates), to decrease withdrawal symptoms, to enhance confidence, to feel normal and to facilitate sexual assault (eg flunitrazepam used as ‘date rape’ drug).³¹

Abuse is a commonly used term with a variety of meanings. It is sometimes used disapprovingly to refer to any use at all, particularly of illicit drugs, while in other contexts abuse has referred to non-medical or unsanctioned patterns of use, irrespective of consequences.³¹

Problematic drug use may be a wider, yet clearer, more descriptive and less judgemental term than misuse or abuse.³¹

Drug-seeking behaviour is a poorly defined term that describes a range of activities directed towards attainment of sought after medications. The most common medications sought are opioids and benzodiazepines. Behaviours include attending multiple practitioners (prescription or doctor shopping) and employing manipulating tactics.²⁰³

A comprehensive list of tactics and behaviours used to obtain medication is available in RACGP’s Prescribing drugs of dependence in general practice, Part A – Clinical governance framework.

Prescription or doctor shopping is when patients unknowingly or deliberately obtain more medicines than is medically needed. This is often done by visiting many doctors, without telling them about their other consultations.²⁰⁴ The Medicare Australia Prescription Shopping Information Service (PSIS) defines prescription shoppers as anyone, within any 3-month period, that has been supplied with PBS items prescribed by six or more different prescribers (including nurse practitioners and midwives, but excluding specialists and consultant physicians), and/or a total of 25 or more target PBS items, and/or a total of 50 or more items.²⁰⁴ Target items are analgesics, anti-epileptics, anti-parkinson medicine, psycholeptics (including antidepressants), and all other nervous system medicine.

Appropriate prescriber behaviour refers to prescription decisions based on evidence at the time of assessment and taking into account the patient’s perspective. This is related to the term accountable prescribing. 

Accountable prescribing is defined as a commitment to evidence-based practice, the use of medicines with proven effectiveness and the avoidance of medicines when they do not help or cause harm.²⁰⁵

Inappropriate prescriber behaviour refers to persistent prescribing of drugs of dependence despite absence of sustained improvement in function, deterioration of function and/or the development of unacceptable side effects.²⁰⁶

Staged supply is the process by which pharmacists supply medicine to a patient in periodic instalments of less than the originally prescribed quantity, at agreed time intervals. The balance of the medicine is held by the pharmacy to fulfil subsequent instalments. This service can be initiated by the pharmacist, the prescriber, the patient (or their carer) or another health professional involved in the patient’s care.²⁰⁷