Diagnosis, identification and risk populations
There are two principle diagnostic classification systems:
- ICD-10 (International Classification of Disease – tenth revision produced by the World Health Organisation)
- DSM-V (Diagnostic Statistical Manual – fifth revision produced by the American Psychiatric Association).
There are similarities between the two but for the purposes of this document we have used ICD-10, which defines opioid dependence (code F11.2) as:
A cluster of physiological, behavioural, and cognitive phenomena in which the use of an opioid takes on a much higher priority for a given individual than other behaviours that once had greater value. A central descriptive characteristic of the dependence syndrome is the desire (often strong, sometimes overpowering) to take opioids (which may or may not have been medically prescribed). There may be evidence that a return to opioid use after a period of abstinence leads to a more rapid reappearance of other features of the syndrome than occurs with nondependent individuals.
ICD-10 states that a definitive diagnosis of dependence should usually be made only if three or more of the following have been present together at some time during the previous year:
(a) a strong desire or sense of compulsion to take opioids;
(b) difficulties in controlling opioid taking behaviour in terms of its onset, termination, or levels of use;
(c) a physiological withdrawal state when opioid use has ceased or been reduced, as evidenced by the typical opioid withdrawal state whose signs and symptoms include: dilated pupils, yawning, rhinorrhoea (runny nose), sweating, abdominal cramping pain, lacrimation (eyes watering), tremor, nausea and vomiting, agitation, muscle twitches, anxiety, piloerection, and diarrhoea; or use of the same opioid or another opioid, licit or illicit, with the intention of relieving or avoiding withdrawal symptoms;
(d) evidence of tolerance, such that increased doses of the psychoactive substances are required in order to achieve effects originally produced by lower doses (clear examples of this are found in opioid dependent individuals who may take daily doses sufficient to incapacitate or kill non-tolerant users);
(e) progressive neglect of alternative pleasures or interests because of opioid use, increased amount of time necessary to obtain or take the opioids or to recover from its effects;
(f) Persisting with opioid use despite clear evidence of overtly harmful physical or psychiatric consequences, such as harmful depressive mood states, consequent or drug-related impairment of cognitive functioning; efforts should be made to determine that the user was actually, or could be expected to be, aware of the nature and extent of the harm.
ICD-10 does go on to clarify that “It is an essential characteristic of the dependence syndrome that either psychoactive substance taking or a desire to take a particular substance should be present; the subjective awareness of compulsion to use drugs is most commonly seen during attempts to stop or control substance use. This diagnostic requirement would exclude, for instance, surgical patients given opioid drugs for the relief of pain, who may show signs of an opioid withdrawal state when drugs are not given but who have no desire to continue taking drugs.” This is an important distinction in this patient group, the desire to take the substance for non-pain relieving effects must be present in order to make a diagnosis of dependence.
Indicators that suggest the possibility of dependence should be explored in those on a long term opioid prescription:
- Long-term prescribing of opioids for non-cancer conditions.
- Current or past psychiatric illness or profound emotional trauma.
- Reports of concern by family members or carers about opioid use.
- Concerns expressed by a pharmacist or other healthcare professionals about long-term opioid use.
- Insistence that only opioid treatment will alleviate pain and refusal to explore other avenues of treatment.
- Refusal to attend or failure to attend appointments to review opioid prescription.
- Resisting referral for specialist addiction assessment.
- The repeated seeking of prescriptions for opioids with no review by a clinician.
- Repeatedly losing medications or prescriptions.
- Taking doses larger than those prescribed or increasing dosage without consulting the clinician; often coupled with seeking early replacement prescriptions. Associated with continued requests for dose escalations.
- Seeking opioids from different doctors and other prescribers. This can take place within GP practices, often identifying locum doctors or doctors unfamiliar with their case. This may be associated with attempting unscheduled visits.
- Obtaining medication from multiple different providers, NHS and private GPs, repeatedly and rapidly deregistering and registering with GPs, seeking treatment for the same condition from both specialists and GP; or seeking treatment from multiple specialists. This may be coupled with a refusal to agree to writing to the main primary care provider.
- Obtaining medications from the internet or from family members or friends.
- Resisting referrals to acute specialists about complex physical conditions or failing to attend specialist appointments.
- Appearing sedated in clinic appointments.
- Misusing alcohol or using illicit or over-the counter, internet or other prescribed drugs or a past history of alcohol or other drug dependence.
- Deteriorating social functioning including at work and at home.
- Resisting or refusing drug screening.
- Signs or symptoms of injecting opioids or snorting oral formulations.
A comprehensive history should be taken from any patient in whom opioid dependence is suspected. It is important to understand the medical indication for which opioids were prescribed initially. As far as possible, confrontation should be avoided, as should judgement about the motivations of the patient. Important points that should be clarified include:
- Medical indication for opioid.
- Full list of all medication, routes of administration and how long prescribed.
- What other medication with addictive potential is prescribed to the patient including benzodiazepines and gabapentin/pregabalin.
- What the patient perceives as positive and negative attributes of prescribed opioids.
- Current alcohol and illicit drug use.
- Current physical health.
- Current psychological health.
- Current tobacco consumption.
- Previous history of drug and alcohol dependence and treatment.
- Physical health history and any interventions.
- History of psychiatric illness.
- Social functioning and employment status.
- Family and carer support.
- Appropriate physical examination.
- Urine or other drug screening for prescribed opioid and commonly abused illicit drugs.
- Consider use of the Objective Opioid Withdrawal Scale (OOWS) and the Subjective Opioid Withdrawal Scale (SOWS) where relevant.
- Relevant blood tests possibly including full blood count, liver function tests, hepatitis B & C, and HIV.
- Any other relevant investigations regarding condition for which opioids were initially prescribed.
Other sources of information should be sought including:
- Discuss with other clinicians currently (or previously where relevant) involved in patients care.
- Clinic letters regarding prescription or underlying diagnosis
- Information from family or carers
Broadly speaking three groups are at increased risk of dependence on prescribed opioids. These groups are not mutually exclusive. They are:
- Patients who find the mood-elevating effects of opioids beneficial but have underlying psychological distress or diagnosed psychiatric illness. Any patient on long-term opioids should be reviewed regarding their psychological health. This is especially true of those with a current or past history of psychiatric illness. In these cases they warrant treatment for opioid dependence, but of equal importance is treatment of the underlying psychiatric condition.
- Those without psychological distress who find themselves dependent but are very willing to engage in reduction programs and further addiction treatment.
- Those with a history of alcohol or drug dependence who may or may not be willing to engage in further assessment or treatment.
NB: Long-term epidemiological data show that patients with co-morbid mental health diagnoses or a history of addiction are more likely to receive opioids for pain and are more likely to be prescribed high doses, multiple opioids and other psychoactive drugs (eg, benzodiazepines). This phenomenon has been described as ‘adverse selection’.
- Edlund MJ, Martin BC, Devries A, et al. . Trends in use of opioids for chronic non-cancer pain among individuals with mental health and substance use disorders: the TROUP study. Clinical Journal of Pain 2010; 26: 1-8.
- Edlund MJ, Martin BC, Fan MY, et al. An analysis of heavy utilizers of opioids for chronic non-cancer pain in the TROUP study. Journal of Pain and Symptom Management 2010; 40: 279-89.
- Morasco BJ, Duckart JP, Carr TP, et al. Clinical characteristics of veterans prescribed high doses of opioid medications for chronic non-cancer pain. Pain 2010;151: 625-32.