This document discusses the objectives and key topics of clinical toxicology. It aims to provide an understanding of general toxicology principles, the approach to treating a poisoned patient, and preventing absorption and counteracting the effects of toxins. The initial priorities for a poisoned patient are to evaluate vital signs and conduct tests to identify the type and specifics of poisoning. Treatment focuses on supportive care while preventing further absorption and counteracting toxic effects at receptor sites if possible.

1. CLINICALCLINICAL
TOXICOLOGYTOXICOLOGY
Joseph Hanig, Ph.D.Joseph Hanig, Ph.D.

2. LEARNING OBJECTIVESLEARNING OBJECTIVES
 To understand the general principles ofTo understand the general principles of
clinical toxicologyclinical toxicology
 To know general factors that influenceTo know general factors that influence
toxicitytoxicity
 To understand the initial approach to theTo understand the initial approach to the
poisoned patient in terms of settingpoisoned patient in terms of setting
immediate prioritiesimmediate priorities
 To appreciate the necessity to conduct, asTo appreciate the necessity to conduct, as
the first order of business, thosethe first order of business, those
procedures that evaluate and preserveprocedures that evaluate and preserve
vital signsvital signs

3. LEARNING OBJECTIVESLEARNING OBJECTIVES
 To know what aspects of the physicalTo know what aspects of the physical
examination and what diagnostic tests areexamination and what diagnostic tests are
to be conducted to evaluate the generalto be conducted to evaluate the general
type as well as the specifics of thetype as well as the specifics of the
poisoningpoisoning
 To understand the goals of treatment e.g.To understand the goals of treatment e.g.
to treat the patient, not the poison,to treat the patient, not the poison,
promptlypromptly
 To know and understand strategies forTo know and understand strategies for
treatmenttreatment
 To know and understand specificTo know and understand specific
approaches for reducing the body burdenapproaches for reducing the body burden
of various poisonsof various poisons

4. LEARNING OBJECTIVESLEARNING OBJECTIVES
 To know how to counteract toxicologicalTo know how to counteract toxicological
effects at receptor sites, if possibleeffects at receptor sites, if possible
 To know and understand importantTo know and understand important
treatment contraindications that preventtreatment contraindications that prevent
serious injury or death of patientsserious injury or death of patients
 To be aware of newer approaches andTo be aware of newer approaches and
treatment modalitiestreatment modalities
 To know where to rapidly obtain facts,To know where to rapidly obtain facts,
specific antidotes, or other information onspecific antidotes, or other information on
poison control needed immediately topoison control needed immediately to
treat the patienttreat the patient

6. Common Causes of Death in theCommon Causes of Death in the
Acutely Poisoned PatientAcutely Poisoned Patient
 Comatose patient:Comatose patient:
– Loss of protective reflexesLoss of protective reflexes
– Airway obstruction by flaccid tongueAirway obstruction by flaccid tongue
– Aspiration of gastric contents intoAspiration of gastric contents into
tracheobronchial treetracheobronchial tree
– Loss of respiratory driveLoss of respiratory drive
– Respiratory arrestRespiratory arrest
 Hypotension – due to depression ofHypotension – due to depression of
cardiac contractilitycardiac contractility

7. Common Causes of Death in theCommon Causes of Death in the
Acutely Poisoned PatientAcutely Poisoned Patient
 Shock – due to hemorrhage or internalShock – due to hemorrhage or internal
bleedingbleeding
 Hypovolemia – due to vomiting, diarrheaHypovolemia – due to vomiting, diarrhea
or vascular collapseor vascular collapse
 Hypothermia – worsened by i.v. fluidsHypothermia – worsened by i.v. fluids
administered rapidly at room temperatureadministered rapidly at room temperature
 Cellular hypoxia – in spite of adequateCellular hypoxia – in spite of adequate
ventilation and Oventilation and O22 admin. – due to CN, COadmin. – due to CN, CO
or Hor H22S poisoningS poisoning

8. Common Causes of Death in theCommon Causes of Death in the
Acutely Poisoned PatientAcutely Poisoned Patient
 Seizures – may result in pulmonarySeizures – may result in pulmonary
aspiration;asphyxiaaspiration;asphyxia
 Muscular hyperactivity resulting inMuscular hyperactivity resulting in
hyperthermia, muscle breakdown,hyperthermia, muscle breakdown,
myoglobinemia, renal failure, lacticmyoglobinemia, renal failure, lactic
acidosis and hyperkalemiaacidosis and hyperkalemia
 Behavioral effects –traumatic injuryBehavioral effects –traumatic injury
ferom fights, accidents, fall from hihferom fights, accidents, fall from hih
places. Suicides, etcplaces. Suicides, etc

9. Common Causes of Death in theCommon Causes of Death in the
Acutely Poisoned PatientAcutely Poisoned Patient
 Massive damage to a specific organMassive damage to a specific organ
system:system:
– Liver (acetaminophen; amanitaLiver (acetaminophen; amanita
phylloides [poison mushroom]phylloides [poison mushroom]
– Lungs (paraquat)Lungs (paraquat)
– Brain (demoic acid)Brain (demoic acid)
– Kidney (ethylene glycol)Kidney (ethylene glycol)
– Heart (cobalt salts)Heart (cobalt salts)
Note: death may occur in 48 – 72 hrsNote: death may occur in 48 – 72 hrs

12. APPROACH TO THE POISONEDAPPROACH TO THE POISONED
PATIENTPATIENT
 History; Oral statements concerningHistory; Oral statements concerning
detailsdetails
 Call Poison Control Center re: drugCall Poison Control Center re: drug
labelinglabeling
 Initial physical examinationInitial physical examination
 Assessment of vital signsAssessment of vital signs
 Eye examinationEye examination
 CNS and mental status examinationCNS and mental status examination

13. APPROACH TO THE POISONEDAPPROACH TO THE POISONED
PATIENTPATIENT
 Examination of the skinExamination of the skin
 Mouth examinationMouth examination
 Lab (clinical chemistry and x-rayLab (clinical chemistry and x-ray
proceduresprocedures
 Renal function testsRenal function tests
 EKGEKG
 Other screening testsOther screening tests

14. TREATMENT OF ACUTETREATMENT OF ACUTE
POISONINGPOISONING
 Treat the patient, not the poison",Treat the patient, not the poison",
promptlypromptly
 Supportive therapy essentialSupportive therapy essential
 Maintain respiration and circulation –Maintain respiration and circulation –
primaryprimary
 Judge progress of intoxication by:Judge progress of intoxication by:
Measuring and charting vital signs andMeasuring and charting vital signs and
reflexesreflexes

16. TREATMENT OF ACUTETREATMENT OF ACUTE
POISONINGPOISONING
 - 1st Goal - keep concentration of- 1st Goal - keep concentration of
poison as low as possible bypoison as low as possible by
preventing absorption and increasingpreventing absorption and increasing
eliminationelimination
 - 2nd Goal - counteract toxicological- 2nd Goal - counteract toxicological
effects at effector site, if possibleeffects at effector site, if possible

17. PREVENTION OF ABSORPTIONPREVENTION OF ABSORPTION
OF POISONOF POISON
 Decontamination from skin surfaceDecontamination from skin surface
 Emesis: indicated after oral ingestion ofEmesis: indicated after oral ingestion of
most chemicals;most chemicals;
– must consider time since chemical ingestedmust consider time since chemical ingested
 Contraindications:Contraindications:
 ingestion of corrosives such as strong acid or alkali;ingestion of corrosives such as strong acid or alkali;
 if patient is comatose or delirious;if patient is comatose or delirious;
 if patient has ingested a CNS stimulant or isif patient has ingested a CNS stimulant or is
convulsing;convulsing;
 if patient has ingested a petroleum distillateif patient has ingested a petroleum distillate

18. PREVENTION OF ABSORPTIONPREVENTION OF ABSORPTION
OF POISONOF POISON
 Induce emesis in the followingInduce emesis in the following
ways:ways:
 mechanically by stroking posteriormechanically by stroking posterior
pharynx;pharynx;
 use of syrup of ipecac, 1 oz followed byuse of syrup of ipecac, 1 oz followed by
one glass of water;one glass of water;
 use of apomorphine parenterallyuse of apomorphine parenterally

19. PREVENTION OF ABSORPTIONPREVENTION OF ABSORPTION
OF POISONOF POISON
 Gastric lavage: insert tube intoGastric lavage: insert tube into
stomach and wash stomach withstomach and wash stomach with
water or ½ normal saline to removewater or ½ normal saline to remove
unabsorbed poisonunabsorbed poison
 Contraindications are the same asContraindications are the same as
for emesis except that thefor emesis except that the
procedure should not be attemptedprocedure should not be attempted
with young childrenwith young children

20. PREVENTION OF ABSORPTIONPREVENTION OF ABSORPTION
OF POISONOF POISON
 Chemical AdsorptionChemical Adsorption
 activated charcoal will adsorb manyactivated charcoal will adsorb many
poisons thus preventing their absorptionpoisons thus preventing their absorption
 do not use simultaneously with ipecac ifdo not use simultaneously with ipecac if
poison is excreted into bile in active formpoison is excreted into bile in active form
 adsorbent in intestines may interruptadsorbent in intestines may interrupt
enterohepatic circulationenterohepatic circulation

21. PREVENTION OF ABSORPTIONPREVENTION OF ABSORPTION
OF POISONOF POISON
 PurgationPurgation
 Used for ingestion of enteric coated tabletsUsed for ingestion of enteric coated tablets
when time after ingestion is longer thanwhen time after ingestion is longer than
one hourone hour
 Use saline cathartics such as sodium orUse saline cathartics such as sodium or
magnesium sulfatemagnesium sulfate
 Chemical InactivationChemical Inactivation
 Not generally done, particularly for acids orNot generally done, particularly for acids or
bases or inhalation exposurebases or inhalation exposure
 For ocular and dermal exposure as well asFor ocular and dermal exposure as well as
burns on skin; treat with copious waterburns on skin; treat with copious water

22. PREVENTION OF ABSORPTIONPREVENTION OF ABSORPTION
OF POISONOF POISON
 Alteration of biotransformationAlteration of biotransformation
 Interfere with metabolic conversion ofInterfere with metabolic conversion of
compound to toxic metabolitecompound to toxic metabolite
 Metabolism of some compoundsMetabolism of some compounds
produces highly reactive electrophilicproduces highly reactive electrophilic
intermediates; if nucleophiles present,intermediates; if nucleophiles present,
toxicity is minimal; if nucleophilestoxicity is minimal; if nucleophiles
depleted, toxicity resultsdepleted, toxicity results
 Increasing urinary excretion byIncreasing urinary excretion by
acidification or alkalinizationacidification or alkalinization

23. PREVENTION OF ABSORPTIONPREVENTION OF ABSORPTION
OF POISONOF POISON
 Decreasing passive resorption fromDecreasing passive resorption from
nephron lumennephron lumen
 DiuresisDiuresis
 CatharticsCathartics
 Peritoneal dialysisPeritoneal dialysis
 HemodialysisHemodialysis
 HemoperfusionHemoperfusion

25. Antagonism of the absorbed poisonAntagonism of the absorbed poison
 If poisoning is due to agonist actingIf poisoning is due to agonist acting
at receptors for which specificat receptors for which specific
antagonist is available; antagonistantagonist is available; antagonist
may be availablemay be available
 Drugs that stimulate antagonisticDrugs that stimulate antagonistic
physiologic mechanisms may of littlephysiologic mechanisms may of little
clinical value; titration difficultclinical value; titration difficult
 Use of antibodiesUse of antibodies

26. Strategies for Treatment of theStrategies for Treatment of the
Poisoned PatientPoisoned Patient
 Evaluate and stabilize vital signsEvaluate and stabilize vital signs
 Give supportive therapy, if neededGive supportive therapy, if needed
 Determine the type and specifics ofDetermine the type and specifics of
the poisonthe poison
 Time of exposureTime of exposure
 Determine the presumed currentDetermine the presumed current
location of the poisonlocation of the poison
 Determine Volume of DistributionDetermine Volume of Distribution
and Kand Kii for the poisonfor the poison

27. Strategies for Treatment of theStrategies for Treatment of the
Poisoned PatientPoisoned Patient
 Use the drug dissociation constant,Use the drug dissociation constant,
presumed pH based on location and thepresumed pH based on location and the
Henderson-Hasselbach equation toHenderson-Hasselbach equation to
determine the ratio of ionized to non-determine the ratio of ionized to non-
ionized poisonionized poison
 Determine the immediate (real time) riskDetermine the immediate (real time) risk
or hazard for absorptionor hazard for absorption
 Intiate body burden reduction proceduresIntiate body burden reduction procedures
or specific antidotes based on the aboveor specific antidotes based on the above
informationinformation

28. Strategies for Treatment of theStrategies for Treatment of the
Poisoned PatientPoisoned Patient
 If volume of distribution is very large; doIf volume of distribution is very large; do
not waste time on any type of dialysisnot waste time on any type of dialysis
 X-ray for location of enteric coated pillsX-ray for location of enteric coated pills
and use cathartics if in the stomachand use cathartics if in the stomach
 Use hypocholesteremics for poisonsUse hypocholesteremics for poisons
trapped in enterohepatic biliary systemtrapped in enterohepatic biliary system

29. SPECIFIC ANTIDOTESSPECIFIC ANTIDOTES
PoisonPoison
AcetaminophenAcetaminophen
Acetylcholinesterases,Acetylcholinesterases,
OP’s, physostigmineOP’s, physostigmine
Iron saltsIron salts
Methanol, EthyleneMethanol, Ethylene
glycolglycol
Mercury, leadMercury, lead
Narcotic drugsNarcotic drugs
Anti/muscarinics-Anti/muscarinics-
cholinergicscholinergics
OP anticholinergicsOP anticholinergics
AntidoteAntidote
AcetylcysteineAcetylcysteine
AtropineAtropine
DeferoximeDeferoxime
EthanolEthanol
Metal ChelatorsMetal Chelators
NaloxoneNaloxone
PhysostigminePhysostigmine
Praladoxime (2-PAM)Praladoxime (2-PAM)