3. DRUG OVERDOSE
Consumption of a therapeutic agent, drug, or narcotic, in excess of that required to produce the
desired effects.
When a drug is eaten, inhaled ,injected or absorbed through the skin in excessive amounts and injures
the body
Overdoses are either intentional or unintentional
Accidental and intentional poisonings or drug overdoses constitute a significant source of aggregate
morbidity, mortality, and health care expenditure worldwide.
4.
5. In 2018, over two million calls were made to United States poison control centers regarding known
or suspected human toxicities
The exact incidence of this problem in our country remains uncertain but it is estimated that about
10-15 million cases of drug overdose poisoning are reported every year ,of which ,more than
50,000 die
6.
7.
8. Most common drugs involved in overdoses
Of the 22,767 deaths relating to pharmaceutical overdose ,16,235 (71.3%) involved opioid
analgesics (Prescription painkillers) an 6973 (30.6%) involved benzodiazepines
Benzodiazepines are frequently found among people treated in ED s for misusing or abusing
drugs
People who died of drug overdoses often had a combination of benzodiazepines and opioid
analgesics in their bodies
9. Risk Factors for drug overdose
Men were 59 % more likely than women to die
High death rates among people 45-49 years of age
Lowest death rates were among children less than 15 years old
10. INITIAL EVALUATION AND TREATMENT
A brief initial screening examination should be performed on all patients to identify immediate
measures required to stabilize and prevent deterioration of the patient.
Assess the airway, vital signs, mental status, pupil size, and skin temperature and moisture.
Immediate diagnostic studies to be performed include pulse oximetry, continuous cardiac
monitoring, an electrocardiogram (ECG), and a capillary glucose measurement (in altered
patients).
Intravenous (IV) access should be obtained in all cases of serious ingestion.
11. In patients with suspected occult trauma, maintain in-line cervical immobilization.
In cases of suspected opioid toxicity, a brief trial of naloxone may be performed prior to
performing tracheal intubation, provided ventilation can be assisted using noninvasive measures.
Provide advanced cardiac life support measures as required.
12. In patients with altered consciousness, a capillary glucose should be performed.
Patients who are hypoglycemic should immediately be given dextrose (25g in adults, 0.5g/kg in
children).
Administer IV naloxone to patients with respiratory depression and signs, symptoms, or a
suggestive of opioid intoxication .
13. The notion that thiamine must be given prior to dextrose to avoid precipitating Wernicke
encephalopathy is unsupported .
Uptake of thiamine into cells is slower than that of dextrose , and withholding dextrose until
administration of thiamine is complete may prove detrimental to those with actual hypoglycemia.
14. Search clothing, wallets, and pocketbooks for pills, pill bottles, or drug-related equipment, but
take care when doing so to avoid a needle stick.
A medical alert bracelet or necklace may provide important history. A more detailed diagnostic
evaluation can then ensue.
A thorough search of the exposure environment should be conducted for pill bottles or a suicide
note, which may provide clues to etiologic agent(s).
Knowledge of drugs prescribed for the patient or the patient's family or friends and to which he
she could have had access may prove important.
15. History — The history, although intuitively the source of the most helpful information for
identifying the etiology of poisoning, is often unreliable when provided by a patient following
intentional ingestion .
16. It is critical to inquire specifically about the use of over-the-counter medications, traditional or
herbal remedies, and dietary supplements
Lastly, drugs of abuse may only be identified by colloquial or slang terms (eg, "ecstasy" for 3,4-
methylenedioxymethamphetamine [MDMA], or "bath salts" for synthetic cathinones)
17. Physical examination — The physical examination of symptomatic poisoned patients may provide
invaluable clues to the agent involved.
The mental status, vital signs, and pupillary examination are the most useful elements and allow
classification of the patient into either a state of physiologic excitation or depression
18. Physiologic excitation
Physiologic excitation (manifested by central nervous system stimulation and increased pulse,
blood pressure, respiratory rate and depth, and temperature) is most commonly caused by
anticholinergic,
sympathomimetic, or
central hallucinogenic agents;
by drug withdrawal states.
19. Physiologic depression
Physiologic depression (manifested by a depressed mental status, blood pressure, pulse,
respiratory rate and depth, and temperature)
is most commonly precipitated by ethanol,
other sedative-hypnotic agents,
opioids,
cholinergic (parasympathomimetic) agents,
sympatholytics, or
toxic alcohols (methanol or ethylene glycol)
20. Mixed physiologic effects
Mixed physiologic effects may occur in polydrug overdoses or following exposure to certain
metabolic poisons (eg, hypoglycemic agents, salicylates, cyanide),
membrane-active agents (eg, volatile inhalants, antiarrhythmic drugs, local anesthetic agents)
heavy metals (eg, iron, arsenic, mercury, lead), or
agents with multiple mechanisms of action (eg, tricyclic antidepressants)
21. Following the initial diagnostic evaluation and stabilization, other physical findings should be
sought to further define a particular toxic syndrome (toxidrome) and to narrow the potential
etiologies of poisoning.
22. Toxidromes
Toxidromes are constellation of symptoms commonly encoutered with certain drug classes
,including anticholinergics ,cholinergics , opioids and sympathomimetics
Evaluation of possible medication poisonings should include basic laboratory studies ,such as a
complete metabolic profile ,to be determine electrolyte imbalances and liver and renal function
23.
24.
25. Toxicokinetics and Toxicodynamics
Toxicokinetics ( Determines the number of molecules that can reach the receptors)
Uptake
Transport
Metabolism and transformation
Sequestration
Excretion
26. Toxicodynamics
Determines the number of receptors that can interact with toxicants
Binding
Interaction
Induction of toxic effects
27.
28. Important Principles of Toxicokinetics
The effect which a drug produces is dependent on
1) The dose
2) The concentration in the target organ
The kinetics of the drug may differ from therapeutic dose to its toxic dose
Toxicokinetics is important in predicting the plasma concentration of the drug
29. Toxicokinetics and Toxicity
Toxicity depends on
Duration and concentration of drug at the portal of entry
The rate and amount (extent) of drug absorbed ,toxicity will be low at slow absorption rates
The distribution of the drug within the body , where most drugs are distributed in highly perfused
organs like brain, liver and kidneys
In some cases,the organ in which the drug is concentrated may not necessarily suffer the
damage
An example is organochlorine compounds concentrated in adipose tissue while the target organ
is brain
30. The efficiency of biotransformation and nature of metabolites ,where in some cases a drug maybe
transformed to more toxic metabolites or a more lipid or water soluble metabolite which affects the
absorption and distribution of the drug .
Eg) paracetamol ,(INH ,dapsone ,hydralazine
The ability of the drug to pass through cell membranes and interaction with cell constituents
Example , some organochlorine affect the DNA
31. The amount and Storage duration of the drug or its metabolites in the tissue .
example Lead in bones is an example
The rate and site of excretion , where the more rapid the excretion less toxicity it will produce
32. Cummulative Toxicity
The state at which repeated administration of a drug may produce effects that are more pronounced
than those produced by the first dose is known as cumulative effectand resultsbinto cumulative toxicity
Anticancer drugs induced cardiotoxicity
Non cardiac pulmonary Edema – methotrexate,cocaine, hhydrochlorothiazide ,iodinated contrast
agents ,opiates , hydrocodone,morphine etc)
Bronchiolitis obliternans organising pneumonia – Acebutolol, Amiodarone , Amphotericin B ,Bleomycin
, carbamazepine
Bronchospasm – Amp B ,Asprin ,Amiodarone ,ACEI , beta blockers
Iron , lead ,mercury ,aluminium ,arsenic – developmental disorders ,degenerative disorders
,haematological disorders
42. Investigations
12 lead Electrocardiogram
Blood glucose , Anion gap plus lactate and osmolal gap
LFT and coagulation profile
Arterial blood gas analysis
Comprehensive Toxicology screen not normally indicated in emergency treatment unless
suspected cases
Urinalysis - ?rhadomyolysis , save sample for toxicological analysis
CXR if pulmonary edema/ aspiration suspected
CT scan brain may be needed to exclude other causes of alterations in conscious level
43. Treatment
Supportive care
Prevention of further exposure
Absorption
Enchancement of toxin elimination
Administration of antidotes
Prevention of reexposure
44. Supportive care
It include support of ABC and vital signs
And also to prevent and treat secondary complications such as aspiration , cerebral and
pulmonary edema ,pneumonia , renal failure ,sepsis ,thromboembolic disease and generalised
organ dysfunction to hypoxemia or shock
45. DECONTAMINATION
A. DECONTAMINATION OF THE SKIN
cleansing with soap and water – used after dermal exposure to organophosphates
Cleansing with acetic acid ( vinegar ) for nicotine
B . DECONTAMINATION OF THE STOMACH
Emesis
Gastric lavage
Activated charcoal
Endoscopic removal
C. DECONTAMINATON OF THE INTESTINES BY WHOLE BOWEL IRRIGATION (WBI)
48. Differential diagnosis
Head trauma( especially ,in the ethanol intoxicated patient)
Stroke / subarachinoid hemoorhage (SAH)
Meningitis
Metabolic abnormalities ( such as hypoglycaemia , hyponatremia , hypoxemia)
Liver disease
Post ictal state
49. Poisoning reporting centres
Toxbase :NHS intranet and internet based information from National poisons information centre
Mims Colour index or TICTAC ( a computer aided tablet and capsule identification system
available to authorised users ,including regional Drug information Centres and Poisons
Information centres to aid pill identification
CMC Vellore Toxicology center