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Identification of Illegal Drug Overdose and Diagnosis of Illegal Drug Poisoning

Essentials

  • Overdosing on illegal drugs is usually accidental. Suicide attempts are rare.
  • In adults, severe poisoning practically always represents mixed poisoning, usually involving hypnotics, sedatives and alcohol.
    • Users do not necessarily know what they have taken.
    • Illegal drugs may contain something other than was believed; contents and concentrations may vary.
  • Users of illegal injection drugs often have blood-transmitted infections, such as hepatitis or HIV.
  • Injection may be associated with vascular or nerve injury or acute infections.
    • Due to vascular damage, it may be difficult to establish vascular access.
  • Treatment may be delayed due to fear of the police or attempts to use "home remedies", such as cold baths.
  • Notice that there may be country-specific or regional differences in the availability and frequency of use of different substances and consequently various types of overdosing incidents.

Substances involved

  • The illegal drugs most often encountered in initial treatment and emergency services treating overdose are, in order of frequency:
    • gammabutyrolactone (GBL) / gammahydroxybutyrate (GHB) (G, Gina, Liquid E, Liquid Ecstasy)
    • opioids, particularly buprenorphine
    • amphetamine and similar designer drugs
    • hallucinogenic agents, such as phencyclidine derivatives.
  • For financial benefit, illegal drugs can be mixed or cut with substances that are toxic themselves.
  • Ingested packets may leak or cause delayed poisoning.
    • Packets swallowed hastily in association with arrest, for instance, leak more easily than packets that were well packed for smuggling.

Prescription drugs and counterfeit prescription drugs

  • Opioids, in particular buprenorphine, benzodiazepines and pregabalin, for instance, can be abused.
  • People may try to extract or separate drugs from pharmaceutical products, such as combinations of paracetamol and codeine, fentanyl patches and cough medicines.
  • Counterfeit prescription drugs may look genuine but may contain designer drugs, for instance, such as designer benzodiazepines or opioids.

CNS stimulants

  • CNS stimulants include:
    • phenethylamines (amphetamine-type, many designer drugs, recreationally used ADHD medication, such as methylphenidate)
    • cocaine (including crack and free base cocaine).
  • The effects of CNS stimulating drugs (see T1) are mainly based on increased secretion or inhibited reuptake at nerve endings of catecholamines, in some cases also of serotonin.
  • It may be difficult to distinguish between different sympathomimetics based on their acute effects.
  • The effect of cocaine is usually briefer than that of amphetamines (tens of minutes vs. tens of hours).

CNS depressants

  • The most common CNS depressants are gammabutyrolactone/gammahydroxybutyrate (GBL/GHB, G, Liquid E), opioids, and illegal and prescription drugs.
    • Hallucinogenic agents, such as phencyclidine, may also have CNS depressant effects.

Symptoms and findings

  • In illegal drug overdose, the problem is usually a decreased level of consciousness and respiratory depression and, more rarely, symptoms and findings associated with sympathomimetic toxicity; see Table T2.
  • In addition to displaying needle marks, patients may possess:
    • needles, syringes, pipes or other drug paraphernalia
    • powder, granules or paste in small bottles or wrapped in plastic, plastic film or foil.

Workup

  • There is no reliable bedside test for diagnosing overdose of illegal drugs.
  • Saliva or urine drug tests are screening tests and not diagnostic.
    • They may give false positive or false negative results.
    • Positive results must be confirmed by a blood test and, in practice, it will take several days, at least, to obtain the results.
    • The tests cannot identify several designer drugs, for instance.

Differential diagnosis

  • See Table T2.

Treatment

  • The treatment of poisoning is symptomatic.
  • See Treatment of Poisoning for details.
  • Ensure airway patency, oxygenation and ventilation aiming for SpO2> 95% and prevention of aspiration.
  • A convulsive seizure is a sign of severe poisoning and should be treated with a benzodiazepine http://www.dynamed.com/condition/seizure-in-adults#BENZODIAZEPINES_FOR_SEIZURE_CESSATION.
  • If there is hyperthermia, external cooling should be started by undressing the patient and removing any covers.
    • Agitation and muscle activity can be reduced by sedation (benzodiazepines).
    • Physical restriction, such as restraints, should be avoided because it typically increases agitation.
  • The specific antidotes for opioid and benzodiazepine poisoning are naloxone and flumazenil, respectively. However, when using these it should be noted that reversing the effects of an opioid or benzodiazepine completely may be fatal in the case of mixed poisoning where the depressant effects of one agent protect the patient from the toxicity of another (e.g. stimulant + opioid) http://www.dynamed.com/management/benzodiazepine-toxicity-emergency-management#THERAPY.
    • Administer carefully, monitoring the response

CNS stimulants

Effects and withdrawal symptoms of CNS-stimulating drugs

Neuropsychiatric effectsEuphoria
Motor restlessness, trismus and bruxism, convulsions
Anxiety, sleeplessness
Anorexia
Confusion, agitation and delirium
Hallucinations, and paranoia, in particular
Headache
Sympathomimetic effectsTachycardia, other arrhythmias, hypertension
Mydriasis
Sweating
Tachypnoea
Tremor
Nausea
Vasospasms, acute coronary syndrome
Cerebrovascular disturbances
Arterial dissection
Activation of the serotonin systemA feeling of unity and empathy
Raised body temperature, even thermoplegia
Hyperthermia
  • Particularly the phenethylamines ecstasy (MDMA), PMA and PMMA
Other possible effects and findingsCocaine increases platelet aggregation and as a local anaesthetic blocks sodium channels.
  • Causes myocardial hypoxia, arrhythmias and convulsions, for instance, more readily than amphetamines do.
  • In the case of massive cocaine overdose, local anaesthetic poisoning
Rhabdomyolysis
Hyponatraemia
Hyperglycaemia
Kidney and/or liver failure
Pulmonary oedema of non-cardiac origin
Metabolic acidosis
Ischaemic colitis
Blood coagulation disorders (DIC)
Obstetric complications, such as miscarriage
Withdrawal symptomsNo physical withdrawal symptoms
Tiredness, fatigue and depression may occur.

Symptoms and findings in patients taking an overdose of illegal drugs, and differential diagnosis

CNS depressantsSymptoms and findingsDecreased level of consciousness, respiratory depression
Hypothermia
Aspiration pneumonia
Rhabdomyolysis
Differential diagnosisSepsis, meningoencephalitis or other severe infection
Hypoglycaemia, hyponatraemia
Hypoxic ischaemic brain damage, craniocerebral trauma or spontaneous cerebral event
Nonconvulsive status epilepticus, psychogenic non-epileptic seizure
Severe hypothermia
CNS stimulantsSymptoms and findingsAggressive and disoriented behaviour, "excited delirium"
Hyperthermia, thermoplegia
Hypertensive crises or arrhythmias in young, previously healthy people
Convulsions
Differential diagnosisPsychiatric disease without drug abuse
Spontaneous intracranial haemorrhage or craniocerebral trauma
Hypoglycaemia
Meningoencephalitis