146 - Substance intoxication

Substance intoxication

469 Disorders due to substance use or addictive behaviours Substance intoxication Available categories by substance class 6C40.3 Alcohol intoxication 6C41.3 Cannabis intoxication 6C42.3 Synthetic cannabinoid intoxication 6C43.3 Opioid intoxication 6C44.3 Sedative, hypnotic or anxiolytic intoxication 6C45.3 Cocaine intoxication 6C46.3 Stimulant intoxication, including amfetamines, methamfetamine and methcathinone 6C47.3 Synthetic cathinone intoxication 6C48.2 Caffeine intoxication 6C49.3 Hallucinogen intoxication 6C4A.3 Nicotine intoxication 6C4B.3 Volatile inhalant intoxication 6C4C.3 MDMA or related drug intoxication, including MDA 6C4D.3 Dissociative drug intoxication, including ketamine and PCP 6C4E.3 Other specified psychoactive substance intoxication 6C4F.3 Intoxication due to multiple specified psychoactive substances 6C4G.3 Intoxication due to unknown or unspecified psychoactive substances Essential (required) features • The presentation is characterized by transient and clinically significant disturbances in consciousness, cognition, perception, affect, behaviour or coordination that develop during or shortly after the consumption or administration of a substance. • The symptoms are compatible with the known pharmacological effects of the substance, and their intensity is closely related to the amount of the substance consumed. • The symptoms of intoxication are time-limited, and abate as the substance is cleared from the body. • Symptoms are not better accounted for by another medical condition (see Box 6.1) or another mental disorder, including another disorder due to substance use (e.g. substance withdrawal). Note: Table 6.15 (p. 475) lists clinically important presenting features of substance intoxication attributable to the pharmacological effects of each substance class. Diagnostic requirements for disorders due to substance use | Substance intoxication

Clinical Descriptions and Diagnostic Requirements for ICD-11 Mental, Behavioural or Neurodevelopmental Disorders Severity of intoxication specifier Depending on the specific clinical situation and the information available, substance intoxication may be classified according to the level of severity as mild, moderate or severe. The level of intoxication is usually related to the dose, route of administration, half-life and duration of action of the substance. Severity of intoxication is also affected by individual variability (e.g. differences in body weight, substance metabolism, tolerance). Susceptibility to substance intoxication may also be greater in individuals with comorbid medical conditions affecting drug pharmacokinetics (e.g. renal or hepatic insufficiency). For some substances, there are specific tests for detecting and determining the concentration of substances in bodily fluids (e.g. blood, urine), which can be important tools for clinical management. However, severity of intoxication should be determined on the basis of clinical assessment, as specified below, and not solely based on the presence and level of the substance in bodily fluids. The level of medical attention that may be required in response to substance intoxication varies according to the severity of intoxication and the substance involved, and varies from precautionary observation to urgent intervention to prevent death or permanent harm (e.g. administration of antagonist treatment, intubation). Severity of intoxication can be rated as mild (XS5W), moderate (XS0T) or severe (XS25), using extension codes, in addition to the appropriate substance intoxication category. To indicate severity, the code for the appropriate severity level is appended to the substance intoxication diagnostic code using an ampersand (&). For example, “6C43.3&XS25” is the code for opioid intoxication, severe. Box 6.1. Examples of medical conditions that may present with symptoms similar to substance intoxication • Head injury (with or without cerebral contusion or intracranial haemorrhage or haematoma) • Meningitis and encephalitis • Diabetic ketoacidosis or hypoglycaemia • Hepatic or other metabolic encephalopathy • Wernicke’s encephalopathy • Electrolyte disturbance • Hypoxia or hypercapnia • Systemic infection Diagnostic requirements for disorders due to substance use | Substance intoxication

471 Disorders due to substance use or addictive behaviours Mild substance intoxication Mild substance intoxication is a state in which there are clinically recognizable disturbances in psychophysiological functions and responses (e.g. motor coordination, attention and judgement) that vary by substance (see Table 6.15, p. 475), but there is little or no disturbance in the level of consciousness. Moderate substance intoxication Moderate substance intoxication is a state in which there are marked disturbances in psychophysiological functions and responses (e.g. motor coordination, attention and judgement) that vary by substance (see Table 6.15, p. 475), with substantial impairment on tasks that require these functions. There is some disturbance in level of consciousness. Severe substance intoxication Severe substance intoxication is a state in which there are obvious disturbances in psychophysiological functions and responses (e.g. motor coordination, attention and judgement) that vary by substance (see Table 6.15, p. 475), with marked disturbance in level of consciousness. There is severe impairment to the extent that the person may not be capable of self-care or selfprotection, and may be unable to communicate or cooperate with assessment and intervention. Note: extension codes are attached to the category to which they apply using an ampersand (&). For example, 6C40.3&XS0T is the code for alcohol intoxication, moderate and 6C41.3&XS5W is the code for cannabis intoxication, mild. Additional clinical features for substance intoxication • Psychoactive substances, whether of the same or a different pharmacological class, may interact such that they exacerbate or modify the features of intoxication. In cases of multiple psychoactive substance use in which more than one specific substance can be identified as a cause of the intoxication, it is recommended that the corresponding specific substance intoxication categories for each relevant substance should be assigned (e.g. 6C40.3 Alcohol intoxication and 6C41.3 Cannabis intoxication) rather than 6C4F.3 Intoxication due to multiple specified psychoactive substances. • Substance intoxication may occur in the presence of medical conditions that cause impairment of levels of consciousness, cognition, perception, affect, behaviour or coordination, which should be diagnosed separately. Determination of the etiology of the disturbances in psychophysiological functions or responses may require longitudinal assessment. • A diagnosis of intoxication due to unknown or unspecified psychoactive substances can be assigned if the substance consumed is initially unknown to the clinician. As more information becomes available (e.g. laboratory results, report from a collateral informant) the diagnosis should be changed to indicate the substance responsible for intoxication. XS5W XS0T XS25 Diagnostic requirements for disorders due to substance use | Substance intoxication

Clinical Descriptions and Diagnostic Requirements for ICD-11 Mental, Behavioural or Neurodevelopmental Disorders Boundary with normality (threshold) • Measurement of the presence or concentration of a substance in breath, blood, saliva, urine or other body fluids may be an important tool in the clinical management of substance intoxication. However, detection of a psychoactive substance in body fluids does not constitute a presumptive diagnosis of substance intoxication. Course features • The onset of substance intoxication varies according to the route of administration, the absorption of the substance and other pharmacokinetic factors. Generally, inhalation (smoking) and intravenous injecting routes lead to more rapid onset of intoxication, although oral ingestion may also lead to intoxication within minutes, depending on the substance. • Substance intoxication is a transient condition, with the duration of intoxication depending on multiple factors, including the dose of the substance taken, the half-life and duration of action of the particular substance, and the formulation of the substance taken (e.g. for pharmaceutical preparations, whether a controlled-release drug has been taken). Intoxication may last from a few minutes to several days following the episode of use. The intensity of intoxication lessens with time after reaching a peak of absorption, and the effects eventually disappear in the absence of further use of the substance. Developmental presentations • Naive users – including adolescents – can show features of intoxication at lower levels of use, reflecting lower physical and learned tolerance. • Older adults may have a lower tolerance than younger people to the effects of alcohol and other substances. Culture-related features • The degree and characteristics of intoxication displayed for a given amount of the substance vary considerably with circumstances, with beliefs and expectations about the effects of the substance, and with the cultural acceptability of displaying these effects. These factors result in cultural differences in the extent and manifestations of intoxication. Diagnostic requirements for disorders due to substance use | Substance intoxication

473 Disorders due to substance use or addictive behaviours • There are also genetic differences in susceptibility to intoxication associated with certain ethnic groups. Cultural and ethnically linked genetic factors have been better documented for alcohol than for other substances. Sex- and/or gender-related features • The amount of substance and duration of use necessary to cause intoxication differs by sex, reflecting differences in body weight and composition. • Behaviour while intoxicated may vary by gender, reflecting not only physiological differences but also cultural differences and role expectations. Boundaries with other disorders and conditions (differential diagnosis) Boundary with episode of harmful psychoactive substance use and harmful pattern of psychoactive substance use In episode of harmful psychoactive substance use and harmful pattern of psychoactive substance use, consumption or administration of a substance results in damage to the person’s physical or mental health (including a substance-induced mental disorder) or in behaviour leading to harm to the health of others. Recovery from substance intoxication is generally complete. Complications due to such effects of intoxication such as injury, the effects of hypoxia, the effects of prolonged hyperactivity or inactivity, or other tissue damage should be diagnosed as episode of harmful psychoactive substance use or harmful pattern of psychoactive substance use, as appropriate. If relevant at the time of the clinical encounter (e.g. in emergency settings), substance intoxication can be given as an associated diagnosis, with episode of harmful psychoactive substance use or harmful pattern of psychoactive substance use as the primary diagnosis. Boundary with substance dependence Episodic or continuous intoxication with a substance or substances is a typical feature of substance dependence. If all diagnostic requirements of both conditions are met for the same episode of care, substance dependence should be assigned as the primary diagnosis, with an associated diagnosis of substance intoxication (e.g. opioid dependence with opioid intoxication). Boundary with substance withdrawal Substance withdrawal occurs upon cessation or reduction of a substance in the context of physiological dependence or when a substance has been taken for a prolonged period or in large amounts. In contrast, the onset of substance intoxication occurs immediately or shortly after the consumption of a substance. Moreover, for a particular substance, the intoxication and withdrawal syndromes are typically quite distinct. See Table 6.15 (p. 475) for a description of the substance-specific features of substance intoxication and Table 6.16 (p. 484) for a description of the substance-specific features of substance withdrawal. Diagnostic requirements for disorders due to substance use | Substance intoxication

Clinical Descriptions and Diagnostic Requirements for ICD-11 Mental, Behavioural or Neurodevelopmental Disorders Boundary with substance-induced delirium Delirium is characterized by disturbances in attention, orientation and awareness that develop within a short period of time, with symptoms that are transient and may fluctuate depending on the underlying etiology. Delirium often includes disturbance of behaviour and emotion, and may include impairment in multiple cognitive domains. Disturbance of the sleep-wake cycle may also be present. Delirium can be caused by intoxication or withdrawal from substances. When symptoms of delirium are attributable to substance intoxication, an associated diagnosis of substance-induced delirium should be assigned in addition to the diagnosis of substance intoxication. Note: substance-induced delirium is only applicable for some substances or substance classes (see Table 6.14, p. 454). Boundary with other substance-induced mental disorders Mental or behavioural symptoms that arise during substance intoxication should only be used as a basis for diagnosing a substance-induced mental disorder if the intensity or duration of the symptoms is substantially in excess of those that are characteristic of substance intoxication due to the specified substance (see Table 6.15, p. 475), and the symptoms are sufficiently severe to warrant specific clinical attention. Boundary with other medical conditions A variety of medical conditions may produce symptoms that are similar to those of substance intoxication (see Box 6.1 for examples). Some of these medical conditions are life-threatening, and require immediate intervention. Evidence of substance use (e.g. positive laboratory results) does not rule out the possibility of a comorbid medical condition. These alternative diagnoses must be considered in assessing substance intoxication. Certain medical conditions may also augment or prolong the duration of intoxication. Symptoms of intoxication that persist after they can no longer be reasonably attributed to the pharmacological effects of the substance may suggest the presence of another medical condition. If it is determined that substance intoxication is comorbid with a medical condition, both diagnoses should be assigned. Boundary with overdose When consumption or administration of psychoactive substances results in symptoms of overdose (e.g. coma, life-threatening cardiac or respiratory suppression), it is typically more appropriate to apply a diagnosis from the grouping of harmful effects of substances in Chapter 22 on injury, poisoning or certain other consequences of external causes rather than substance intoxication. Table 6.15 sets out the disturbances in consciousness, cognition, perception, affect, behaviour or coordination that are most characteristic of intoxication with each class of psychoactive substances in the grouping of disorders due to substance use. These features are caused by the known pharmacological effects of the substance. Their intensity is closely related to the amount of the substance consumed, as well as the route of administration, interaction of the substance with other substances – including medications – and the duration of action of the substance. They are time-limited, and abate as the substance is cleared from the body. Diagnostic requirements for disorders due to substance use | Substance intoxication

475 Disorders due to substance use or addictive behaviours Table 6.15. Common substance-specific features of substance intoxication Substance Common substance-specific features Alcohol Presenting features of alcohol intoxication may include impaired attention, inappropriate or aggressive behaviour, lability of mood and emotions, impaired judgement, poor coordination, unsteady gait, and slurred speech. At more severe levels of intoxication, stupor or coma may occur. Additional features • Alcohol intoxication may be associated with impaired social interaction. • Impaired coordination and judgement due to alcohol intoxication, even at low doses, may be sufficiently severe to affect the faculties necessary to operate motorized vehicles safely: alcohol intoxication is an important risk factor for road accidents. • The disinhibiting effects of alcohol are associated with an increased risk of attempted and completed suicides. • Higher blood levels of alcohol (e.g. >150 mg/dL) are associated with stupor and coma. Blood levels of alcohol above 250 mg/dL can cause respiratory depression, cardiac arrhythmias and death. • Stupor and coma are more likely to occur in individuals with low tolerance or comorbid medical conditions. • The more severe the intoxication, the greater the likelihood of subsequent amnesia for events that took place during the period of intoxication (“blackouts”). • Some symptoms of intoxication with other substances (e.g. sedatives, hypnotics or anxiolytics; opioids) may be similar to those of alcohol intoxication. Evidence of alcohol use (e.g. the smell of alcohol on the breath) does not rule out concomitant intoxication with other substances. Cannabis or synthetic cannabinoids Presenting features of cannabis intoxication or synthetic cannabinoid intoxication may include inappropriate euphoria, impaired attention, impaired judgement, perceptual alterations (such as the sensation of floating, altered perception of time), changes in sociability, increased appetite, anxiety, intensification of ordinary experiences, impaired short-term memory and sluggishness. Physical signs include conjunctival injection (red or bloodshot eyes), dry mouth and tachycardia. Additional features • The principal psychoactive cannabinoid is cannabis is THC. Disturbances in consciousness, cognition, perception, affect, behaviour or coordination typical of cannabis intoxication are primarily attributable to levels of THC, although various other cannabinoids are also present in cannabis preparations (e.g. dried leaves and buds, hashish, cannabis oil). • Synthetic cannabinoid intoxication may cause delirium or acute psychosis. • Regular intoxication with high potency cannabis or synthetic cannabinoids may be associated with increased long-term risk of psychosis. Note: medicinal cannabinoids such as cannabidiol and cannabinol – for example, those used as antispasmodics, anxiolytics or analgesics – typically have no or minimal intoxicating effects. However, standard laboratory testing for cannabinoids may not be able to differentiate among these different types of cannabinoids. Diagnostic requirements for disorders due to substance use | Substance intoxication

Clinical Descriptions and Diagnostic Requirements for ICD-11 Mental, Behavioural or Neurodevelopmental Disorders Substance Common substance-specific features Opioids Presenting features of opioid intoxication may include somnolence, stupor, mood changes (e.g. euphoria followed by apathy and dysphoria), psychomotor retardation, impaired judgement, respiratory depression, slurred speech, and impairment of memory and attention. In severe intoxication, coma may ensue. A characteristic physical sign is pupillary constriction, but this sign may be absent when intoxication is due to synthetic opioids. Additional features • Severe opioid intoxication can lead to death due to excessive respiratory depression. Overdose is more likely to occur with higher-potency opioids (e.g. fentanyl), when the person has reduced tolerance (e.g. after detoxification) or when an individual who has developed tolerance uses the opioid in a novel environment. • Opioid intoxication shares certain features with alcohol intoxication and sedative, hypnotic or anxiolytic intoxication. Evidence of alcohol use (e.g. the smell of alcohol on the breath) does not rule out co-occurring opioid intoxication. • Where available, laboratory testing for substances that may be contributing to the intoxication or their metabolites may be necessary to identify the intoxicating substance. • Administration of an opioid antagonist (e.g. naloxone) may be used empirically in some settings (e.g. emergency settings) to differentiate opioid intoxication from intoxication with other substances. Sedatives, hypnotics or anxiolytics Presenting features of sedative, hypnotic or anxiolytic intoxication may include somnolence, impaired judgement, inappropriate behaviour (including sexual behaviour or aggression), slurred speech, impaired motor coordination, unsteady gait, mood changes, and impaired memory, attention and concentration. Nystagmus (repetitive, uncontrolled eye movements) is a common physical sign. In severe cases, stupor or coma may occur. Additional features • Impaired memory in sedative, hypnotic or anxiolytic intoxication is characterized by anterograde amnesia for the period of intoxication. • Sedatives, hypnotics or anxiolytics are commonly prescribed medications. They can cause intoxication even in therapeutic doses in older individuals and in those with medical comorbidities. • Some features of sedative, hypnotic or anxiolytic intoxication may be similar to those of opioid intoxication or alcohol intoxication. Evidence of alcohol use (e.g. the smell of alcohol on the breath) does not rule out concomitant sedative, hypnotic or anxiolytic intoxication. • Where available, laboratory testing for substances that may be contributing to the intoxication or their metabolites may be necessary to identify the intoxicating substance. Cocaine Presenting features of cocaine intoxication may include inappropriate euphoria, anxiety, anger, impaired attention, hypervigilance, psychomotor agitation, paranoid ideation (sometimes of delusional intensity), auditory hallucinations, confusion and changes in sociability. Perspiration or chills, nausea or vomiting, and palpitations and chest pain may be experienced. Physical signs may include tachycardia, elevated blood pressure and pupillary dilatation. Additional features • In rare instances – usually in severe intoxication – cocaine use can result in seizures, muscle weakness, dyskinesia and dystonia, and myocardial infarction arising from coronary artery spasm or stroke arising from cerebral artery spasm. Table 6.15. contd Diagnostic requirements for disorders due to substance use | Substance intoxication

477 Disorders due to substance use or addictive behaviours Substance Common substance-specific features Stimulants, including amfetamines, methamfetamine and methcathinone Presenting features of stimulant intoxication may include anxiety, anger, impaired attention, hypervigilance, psychomotor agitation, paranoid ideation (possibly of delusional intensity), transient auditory hallucinations, transient confusion and changes in sociability. Perspiration or chills, nausea or vomiting, and palpitations may be experienced. Physical signs may include tachycardia, elevated blood pressure, pupillary dilatation, dyskinesia and dystonia, and skin sores. Additional features • In rare instances – usually in severe intoxication – use of stimulants, including amfetamines, methamfetamine and methcathinone, can result in seizures. Synthetic cathinones Presenting features of synthetic cathinone intoxication may include anxiety, anger, impaired attention, hypervigilance, psychomotor agitation, paranoid ideation (possibly of delusional intensity), transient auditory hallucinations, transient confusion and changes in sociability. Perspiration or chills, nausea or vomiting, and palpitations may be experienced. Physical signs may include tachycardia, elevated blood pressure, pupillary dilatation, dyskinesia and dystonia, and skin sores. Additional features • In rare instances – usually in severe intoxication – use of synthetic cathinones can result in seizures. Caffeine Presenting features of caffeine intoxication may include restlessness, anxiety, excitement, insomnia, flushed face, tachycardia, diuresis, gastrointestinal disturbances, muscle twitching, psychomotor agitation, perspiration or chills, and nausea or vomiting. Cardiac arrythmias may occur. Disturbances typical of caffeine intoxication tend to occur at relatively high doses (e.g. >1 g per day). Additional features • Caffeine and related alkaloids (e.g. theobromine in tea) are present in a variety of foods (e.g. chocolate, kola nuts), beverages (e.g. sodas, guarana) and supplements (e.g. tablets, vitamins) that are consumed regularly and pervasively. • Very high doses of caffeine (e.g. >5 g) can result in respiratory distress or seizures, and can be fatal. Hallucinogens Presenting features of hallucinogen intoxication may include hallucinations, illusions, perceptual changes such as depersonalization, derealization, synaesthesias (blending of senses, such as a visual stimulus evoking a smell), anxiety, depressed or dysphoric mood, ideas of reference, paranoid ideation, impaired judgement, palpitations, sweating, blurred vision, tremors and lack of coordination. Physical signs may include tachycardia, elevated blood pressure and pupillary dilatation. Additional features • In rare instances, hallucinogen intoxication may increase suicidal behaviour. Table 6.15. contd Diagnostic requirements for disorders due to substance use | Substance intoxication

Clinical Descriptions and Diagnostic Requirements for ICD-11 Mental, Behavioural or Neurodevelopmental Disorders Substance Common substance-specific features Nicotine Presenting features of nicotine intoxication may include restlessness, psychomotor agitation, anxiety, cold sweats, headache, insomnia, palpitations, paraesthesias, nausea or vomiting, abdominal cramps, confusion, bizarre dreams, burning sensations in the mouth and salivation. Additional features • Nicotine intoxication occurs more commonly in people who have recently started smoking or using other forms of nicotine (e.g. electronic cigarettes or “vaping”), and have therefore not developed tolerance. It may also occur in people who receive nicotine therapeutically and take it in higher than recommended doses. • In rare instances, paranoid ideation, perceptual disturbances, convulsions or coma may occur. Volatile inhalants Presenting features of volatile inhalant intoxication may include euphoria, impaired judgement, aggression, somnolence, stupor or coma, dizziness, tremor, lack of coordination, slurred speech, unsteady gait, lethargy and apathy, psychomotor retardation and visual disturbance. Muscle weakness and diplopia may occur. Additional features • Intentional or unintentional exposure to a variety of volatile inhalant substances (e.g. glue, petrol, butane, paint) can cause the symptoms of volatile inhalant intoxication. • Intentional volatile inhalant intoxication typically involves “sniffing” or “huffing” the substances from closed containers, a practice that may lead to hypoxia, hypoxic brain damage and other long-lasting neurological sequelae. • Use of volatile inhalants may cause cardiac arrythmias, cardiac arrest and death. • Inhalants containing lead (e.g. some forms of petrol/gasoline) may cause confusion, irritability, coma and seizures. • Use of volatile inhalants is more common among adolescents and young adults due to the greater ease of access compared to other psychoactive substances. MDMA or related drugs, including MDA Presenting features of MDMA or related drug intoxication may include increased or inappropriate sexual interest and activity, anxiety, restlessness, agitation and sweating. Additional features • In rare instances – usually in severe intoxication – use of MDMA or related drugs, including MDA, can result in dystonia and seizures. Sudden death is a rare but recognized complication. Dissociative drugs, including ketamine and PCP Presenting features of dissociative drug intoxication may include aggression, impulsivity, unpredictable behaviour, anxiety, psychomotor agitation, impaired judgement, numbness or diminished responsiveness to pain, slurred speech and dystonia. Physical signs include nystagmus (repetitive, uncontrolled eye movements), tachycardia, elevated blood pressure, numbness, ataxia, dysarthria and muscle rigidity. Additional features • In rare instances, use of dissociative drugs, including ketamine and PCP, can result in seizures. • Laboratory tests to quantify PCP levels are only weakly correlated with disturbances in consciousness, cognition, perception, affect, behaviour or coordination. Table 6.15. contd Diagnostic requirements for disorders due to substance use | Substance intoxication