Description
Deaths due to poisoning are on the rise over the years, despite advanced knowledge regarding their pharmacokinetics and pathology, and newer and better techniques being developed for the management of poisoning cases.
J Indian Acad Forensic Med. Jan-Mar 2011, Vol. 33, No. 1 ISSN 0971-0973
74
Review Paper
Recent Advances in the Management of Poisoning Cases
*Dasari Harish, **K H Chavali,**Amandeep Singh, ** Ajay Kumar
Abstract
Deaths due to poisoning are on the rise over the years, despite advanced knowledge regarding
their pharmacokinetics and pathology, and newer and better techniques being developed for the
management of poisoning cases. The management of a poisoned patient has changed over the years.
Though the general principles of treatment of a poisoned patient remain the same, traditional methods
like gastric lavage, for example, have taken a back seat. There has been gaining popularity of newer
methods like use of activated charcoal and a variety of newer antidotes. Attention has also shifted to
toxidromes, the collection of symptoms and signs that consistently occur after ingestion of a particular
toxin or drug. Grouping the various signs and symptoms exhibited by a poisoned patient into different
toxidromes helps the physician in rapid identification of the toxidrome and saves time in evaluating and
managing a poisoned patient. However, the mainstay of the treatment, according to the experts is
stabilization of the patient.
Key Words: Poisoning, Poisoned Patient, Management, Gastric Lavage, Charcoal, Toxidromes
Introduction:
“All substances are poisons; there is
none that is not a poison;
The right dose differentiates a poison
from a remedy" – Paracelsus [1]
Poisoning and deaths due to poisoning
are on the rise over the years, despite advanced
knowledge regarding their pharmacokinetics and
pathology, and newer and better techniques
being developed for the management of
poisoning cases. It is estimated that there are
more than nine million synthetic and natural
chemicals available today.[2] In India, the trends
of poisoning have changed over the years, from
insecticides in the earlier times to fumigants, at
present.[3] The commonest agents in India are
the pesticides, followed by sedatives, drugs,
chemicals, alcohols, plant toxins and house-hold
cleansing agents.[4,5] Of late, aluminum
phosphide has emerged as the commonest
suicidal agent in Northern India.[6] In UK,
around 15-20% of workload of medical units is
due to self poisoning,[7] and paracetamol is one
of the commonest drugs involved in self-
poisoning, accounting for 43% of hospital
admissions with history of self-poisoning. [8]
Corresponding Author:
*Professor and Head,
Deptt. of Forensic Medicine & Toxicology,
Government Medical College & Hospital [GMCH],
Chandigarh
Email: [email protected]
** Assistant Professors, FMT, GMCH, Chandigarh
While in the US, it accounted for 4.1% of
deaths from poisoning.[9] The commonest agent
causing deaths in poisoning cases in the UK up
to 1998 was carbon monoxide.[10] The manner
of poisoning differs with the age and poisoning
in the paediatric age group generally occurs due
to accidental ingestion of commercial and
house-hold poisonous products (due generally
to curiosity), while in the adolescents and the
adults, intentional self poisoning is the common
mode.[11]
General Principles:
The general principles of management of
poisoning cases, as we know are:
1. Stabilization ? which includes assessment
and management of
a) The airway and Breathing
b) Circulation, and
c) Depression of the Central Nervous
System
2. Evaluation, if the patient is already stable
3. Decontamination ? including skin/ eye
decontamination, gut evacuation, etc
4. Poison Elimination ? diuresis, peritoneal/
haemo dialysis, haemoperfusion, etc
5. Antidote administration ? As of now,
antidotes are available for < 5% poisons
6. Nursing and Psychiatric care.
Now-a-days, stabilization of the patient
is being considered as the main stay of
management of poisoning emergencies.
Gastrointestinal evacuation, in use for centuries,
is undergoing critical appraisal. The role of
ipecac and gastric lavage are being questioned,
while activated charcoal is gaining importance in
the management of such cases. [12] Antidotal
J Indian Acad Forensic Med. Jan-Mar 2011, Vol. 33, No. 1 ISSN 0971-0973
75
therapy is no more the mainstay of the
management and the fact that we have
antidotes for only about 5% poisons, is mainly
responsible for this development.[13] Grouping
the signs and symptoms produced by the
poisons in to various toxidromes helps in rapid
and effective management of the case.
Gastric Decontamination:
Interference with absorption of ingested
poison from the gastrointestinal tract is the
mainstay of poison management. Because few
specific antidotes are available to treat
poisonings, absorption prevention, observation,
and supportive care are the clinician’s greatest
assets. The challenge for clinicians managing
poisoned patients is to identify those who are
most at risk of developing serious complications
and who might potentially benefit from
gastrointestinal decontamination.[14] American
Academy of Clinical Toxicology and European
Association of Poison Centers & Clinical
Toxicologists gave the position statements in gut
decontamination in 1993. [15, 16]
Table 1: Summary of recommendations [15, 16]
Treatment Indications
Gastric
Lavage
Should not be considered unless a patient has
ingested a potentially life – threatening amount of a
poison and the procedure can be undertaken within
60 minutes of ingestion.
Activated
charcoal
May be considered if a patient has ingested a
potentially toxic amount of the poison (known to be
adsorbed by charcoal) up to 1 hour previously; there
are insufficient data to support or to exclude its use
after 1 hr of ingestion.
Ipecacuanha Its routine administration in the emergency
department should be abandoned; there are
insufficient data to support or to exclude its
administration soon after ingestion.
Whole–bowel
irrigation
May be considered for potentially toxic ingestion of
sustained release or enteric coated drugs; there are
insufficient data to support or to exclude its use for
potentially toxic ingestion of iron, lead, zinc, or
packet of illicit drugs (body – packer)
Cathartics The administration of a cathartic alone has no role
in the treatment of a poisoned patient and is not
recommended as a method of gut decontamination
a) Gastric Lavage:
Stomach emptying by gastric aspiration
and lavage has been in use in the management
of poisoning by ingestion, for almost 200 years.
[14] Studies, as early as 1959 [17] have
demonstrated that gastric lavage is no more
effective than ipecac emesis induced in specific
instance. Other investigators, however, have
challenged those studies on the basis of
improper technique as the studies were carried
out with animals and in non-overdose situations.
The effectiveness of both gastric lavage and
ipecac in removing stomach contents is time
dependent and best results are obtained when
performed within one hour. [12] Unfortunately,
many overdose patients do not arrive to the
emergency department within this valuable one
hour. Although emptying the stomach in the first
hour generally works [12, 18] and may be
beneficial for up to a certain period of time
thereafter, it is usually not helpful beyond 4
hours of ingestion. Sadly, the same is not
applied in our country. Irrespective of the time
gap, gastric lavage is performed in most of the
hospitals, as the initial part of the treatment.
Legal requirement, necessitating the
preservation of a sample of the return lavage
fluid for toxicological analysis, plays an
important role in the continuing use of this
technique, despite its efficacy being highly
questionable.
Gastric lavage carries potential
complications, including aspiration pneumonitis
and, rarely, esophageal perforation. It can also
promote the rapid passage of tablets into the
small bowel rather than removing them. Studies
have now shown that gastric lavage did not
prove any more beneficial than activated
charcoal, alone. [19, 20]
b) Activated Charcoal:
Activated charcoal has been used in the
treatment of poisonings since 1830, when its
effects were first demonstrated by the French
chemist Bertrand.[21] Produced by pyrolysis of
carbon containing materials and activated by
oxidation with steam at a high temperature,
these processed carbon products adsorb many
drugs. Most commercially available preparations
have a surface area of approximately 1000m
2
/g.
In addition to direct intra-luminal binding,
activated charcoal can also decrease the
resorption of agents that undergo enterohepatic
or enterogastric cycling. [22] It also has a
“gastrointestinal dialysis” effect, whereby the
charcoal serves as a large “sink” with movement
of toxin molecules across semi-permeable
membranes from splanchnic circulation. [23]
During the last decade, however,
activated charcoal became increasingly popular
as a first-line agent for the treatment of
poisonings, particularly if more than several
hours have passed since ingestion. It is
generally considered ineffective against
caustics, ethanol, ethylene glycol, methanol, iron
lithium, metals, and petroleum distillates. Usually
complications of its use are rare, but they
include aspiration of activated charcoal and
gastric contents, as well as intestinal
obstruction, particularly when repeated doses of
activated charcoal are given. [24]
The use of multiple-dose activated
charcoal (MDC) is now recommended for the
J Indian Acad Forensic Med. Jan-Mar 2011, Vol. 33, No. 1 ISSN 0971-0973
76
clearance of drugs such as -- carbamazepine,
digitoxin, glutethimide, nadolol, phenobarbital,
phenylbutazone, theophylline, and others. [25]
Multiple dosing appears to decrease both the
absorption and blood concentration of many
drugs. The multiple-dose regimen consists of an
initial dose of 50-100g followed by maintenance
doses of 30-50 g every 2-6 h with or without the
administration of a cathartic agent. Maintaining a
constant amount of activated charcoal in the gut
adsorbs the toxin as it is secreted back in to the
gut, thereby preventing a delayed peak in the
serum concentration. [18]
When activated charcoal is continually
present in the gut, it might act as an infinite
“sink”, keeping the level of the toxin low in the
lumen of the gastrointestinal tract. As most of
the drugs and toxins are absorbed by simple
diffusion, this “sink” may reverse the normal
gradient, and actually permit transit of the toxin
out of the blood in to the lumen of the tract?
gastrointestinal dialysis. [23] This has been
shown to occur with theophylline,
carbamazepine, dapsone, quinine and
Phenobarbital.
Table 2: Charcoal & M D A
Substances not readily adsorbed to activated charcoal[18]
Ferrous salts Acids
Lithium preparations Alkalies
Potassium salts Fluorides
Ethanol Organic solvents
Methanol Mercury and its salts
Ethylene glycol Lead and its salts
Indications for multiple dose activated charcoal[18]
Slow release preparations such as theophylline (but not lithium)
Carbamazepine
Dapsone
Digoxin
Paraquat
Phenobarbitone
Quinine
Amanita phalloides
The Coordination Committee in Accident
and Emergency (A&E) Services of Hong Kong
Protocol advocates activated charcoal as the
treatment of choice for most poisons, except
metals, alcohol, cyanide, acids and alkalies,
which are not adsorbed by it.
c) Cathartics:
Catharsis actually means purification
and this is achieved in the poisoning cases by
purging the gastrointestinal tract of all the
poisonous material. This is the premise that
promotes their use for the rectal evacuation of
gastric contents - both the drug and the drug-
charcoal complex. Despite their widespread use,
however, little evidence exists that cathartics
alter the outcome of poisoned patients. The
most commonly used cathartics are magnesium
sulfate, magnesium citrate, and sorbitol. Sorbitol
works the most quickly; causing bowel
movements within one hour.[12]
Contraindications to cathartics include caustic
ingestions and signs of intestinal obstruction. If
being considered, one dose is generally
sufficient.
d) Whole - Bowel Irrigation:
Polyethylene glycol-electrolyte solutions,
which once were used for bowel cleansing
before surgical procedures, are now being
applied for gastrointestinal decontamination.
These iso-osmotically balanced, non-absorbable
solutions are safe, causing no fluid retention or
electrolyte disturbances.[26] The procedure has
been advocated for overdoses of agents such as
iron, lithium, arsenic, lead-oxide and enteric-
coated or sustained-release medications. In
practice, hemodynamically stable and
cooperative patients are best suited for this
intensive cathartic treatment. [24, 27] Adults
should be given the solution at a rate of 2 L/h,
children at 500 ml/h, either orally or through a
naso-gastric tube. The endpoint of treatment is
a clear effluent, which may take 4-6 hours to
appear. Contraindications include ileus or bowel
obstruction, hemodynamic instability or where
airway cannot be protected. [28]
e) Emesis:
Ipecac syrup has long been used as a
first-line agent for prevention of toxicity from
ingested poisons, especially in children.
However, this is not freely available in our
country [13] and its effectiveness in recovering
ingested substances is poor, and its ability to
reduce the severity of poisoning has never been
demonstrated. Moreover, the emesis induced by
ipecac may preclude the use of other oral
treatment options. [29] It is contraindicated in
ingestion of caustic substances and volatile
hydrocarbons, in patients who have decreased
gag reflex or altered mental status, and in
patients at risk for rapid alteration in
consciousness. Complications of ipecac include
aspiration pneumonia, lethargy, diaphragmatic
rupture, Mallory-Weiss esophageal tears and
cerebral hemorrhages.[30] Ipecac is also still
recommended by poison control centers for use
in the home, where early administration can be
assured.
Laboratory Tests:
Although laboratory analysis of various
body fluids of overdose patients frequently
identifies substances that are clinically
unsuspected, these additional findings rarely
alter the patient’s clinical course, largely
because the presence of a substance does not
necessarily correlate with acute toxicity;
J Indian Acad Forensic Med. Jan-Mar 2011, Vol. 33, No. 1 ISSN 0971-0973
77
moreover, analysis can be time-consuming and
in most clinical settings falls short of being
comprehensive.[12] Most poisoned or overdose
patients do well with supportive care alone.
Again, no rapidly available universal screening
tool exists and many patients require little, if any,
laboratory investigation.
Rational use of Antidotes:
Antidotes are chemical or physiological
antagonists that prevent the toxicological effect
of specific poisons. In most toxicological
emergencies, effective antidotes are not
available. Symptomatic treatment and
supportive care are still the primary approach to
treatment; antidotal therapy often plays a
relatively minor role. When appropriately used
in specific situations, however, antidotes can
substantially reduce morbidity and mortality in
the poisoned patient.
Some Newer Antidotes:
a) Hydroxycobalamin: [31] It is the synthetic
form of vitamin B
12
and is given in cases of
cyanide poisoning presenting with
hypotension, where the conventional
antidote sodium nitrite is contraindicated. It
works by sequestering cyanide from the
plasma-cyanide to give non-toxic
cyanocobalamin. The only adverse effects
are brown discoloration of the body fluids,
nausea and vomiting. The recommended
dose is 5g) of the reconstituted solution over
30 minutes.
b) Digoxin specific antibodies (Fab
antibodies): [32] Digoxin specific antigen
binding fragments are indicated in life
threatening arrhythmia/hyperkalaemia
caused by intoxication with cardiac
glycosides. As the antibodies are produced
in sheep, monitoring for anaphylaxis and
serum sickness is necessary.
c) Esmolol hydrochloride: [32] It is a short
acting cardioselective beta- adrenoceptor
blocking drug that has no sympathomimetic
activity. It is used to control hypertension
and tachyarrythmia due to poisoning by
sympathomimetic drugs.
d) Octreotide: [32] A synthetic polypeptide that
antagonizes pancreatic insulin release, it is
indicated in overdose of insulin or oral
hypoglycemic agents, mainly sulphonylurea.
e) Succimer (2,3dimercaptosuccinicacid):
[33] it is a chelating agent used for the
treatment of lead, mercury and arsenic
poisoning. It is the water soluble analogue of
dimercaprol and can be taken orally.
f) Fomepizole (4-methypyrazol): [33] It is a
potent competitive inhibitor of alcohol
dehydrogenase and prevents the formation
of toxic metabolites following methanol and
ethylene glycol poisoning. It is now preferred
to ethanol as the antidote as it does not
cause sedation.
g) Nalmefene and Naltrexone: [33] they are
long acting opioid antagonists and are used
to manage opioid dependence. They are
more potent than Nalaxone but are much
more expensive.
Toxidromes:
The term was first coined by Mofenson
and Greensher. [34] They are a collection of
symptoms and signs that consistently occur after
ingestion of a particular toxin or drug and can
often be identified with a basic history & physical
examination. Many physicians now group the
various signs and symptoms of the poisons into
different toxidromes as the rapid identification of
the toxidrome saves time in evaluating and
managing a poisoned patient. The various
toxidromes are anticholinergic, cholinergic,
sympathomimetic (adrenergic), opiod and
sedatve-hypnotic. Each of these toxidromes has
specific signs and symptoms and requires a set
pattern of management. Hence even if the
poison cannot be identified, it can be classified
into one of the above syndromes based on the
signs and symptoms exhibited and appropriate
treatment can be initiated.
Conclusion:
There has been a major change in the
treatment of poisoned patients, particularly in the
area of gastric decontamination. The trend is
away from the use of ipecac, except in limited
situations such as accidental ingestions in
pediatric patients. For that reason, activated
charcoal has attained a prominent role, not only
as an adjunct for gastric emptying with either
ipecac or gastric lavage but also for use as the
sole decontamination agent. Gastric lavage still
plays an important role, especially if it can be
performed early, or if drugs are involved that
may delay gastric emptying. Whole–bowel
irrigation is safe and effective in limited
situations such as iron, lithium, or sustained-
release medications, and for body packers.
Antidotes play an important role in specific
situations. Oxygen is extremely useful for the
treatment of CO. Naloxone is useful for the
treatment of opiate intoxication. Fab fragment
antibodies are safe and effective for the
treatment of digitalis intoxication. Despite the
advances in gastric decontamination and the
development of new antidotes, the mainstay of
treatment for the poisoning victim remains
J Indian Acad Forensic Med. Jan-Mar 2011, Vol. 33, No. 1 ISSN 0971-0973
78
supportive care and frequent re-evaluation for a
change in clinical status.
Table 3: Common Toxidromes: Signs and Symptoms [35]
Physical findings Adregenic
Toxidrome
(decongest.,
amphetamine,
cocaine)
Anticholinergic
Toxidrome (antihist.,
phenothiazine)
Cholinergic Toxidrome
(Insecticides)
Opiod Toxidrome Sedative-hypnotic
Toxidrome
(tranquilizer,
barbiturates,
ethanol)
Vital Signs
Resp. Rate Increased No change Increased/ no change Decreased Normal/ decreased
Heart rate Increased Increased Decreased Normal/ decreased Normal
Temperature Increased Increased No change Normal/ decreased Normal
Blood P Increased Increased/ no change No change Normal/ decreased Normal
Physical Examination
Mental status Alert/ agitated Depressed/ confused/
hallucinati ng
Depressed/ confused Depressed Depressed
Pupils Dilated Dilated Constricted Constricted Normal
Mucous membranes Wet Dry Wet Normal Normal
Skin Diaphoretic Dry Diaphoretic Normal Normal
Reflexes Increased Normal Normal/ decreased Normal/ decreased Normal/ decreased
Bowel sounds Increased Decreased Increased Decreased Normal
Urination Increased Decreased Increased Decreased Normal
Other Possible seizures Possible seizures Musclefasciculations
/possibe seizures
-- --
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1. Gallo MA. History and scope of Toxicology. The basic science of
poisons. 6
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2. Current Index of Medical Specialties. Poisoning and its
management. Part 1. May – August 1997;20: 49.
3. Sharma BR, Harish D, Sharma V, Vij K. Poisoning in Northern
India – Changing Trends, Causes and Prevention Thereof. Med.
Sci. Law. 2002; 42(3): 251-257.
4. Dash SK, Mohanty MK, Mohanty S. Socio-demographic profile of
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5. Singh D, Jit I, Tyagi S. Changing trends in acute poisoning in
Chandigarh zone: a 25 years experience from a tertiary care
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6. Harish D, Sharma BR, Sharma V. The present day poisoning
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Science in the new millennium. Univ. of Delhi, Dept. of
Anthropology. 2002: 19-25.
7. Greaves I, Goodacre S, Grout P. Management of drug overdose in
accident and emergency departments in United Kingdom. Accident
Emerg. Med 1996; 13:46-8.
8. Bialas MC, Reid P, Beck P, Lazarus JH, Smith PM, Scorer RC,
et al. Changing patterns of poisoning in a UK Health District
between 1987 – 1988 & 1992 – 1993. Q J Med 1996; 317:1654-7.
9. Litovitz TL, Klien-Schwartz W, Dyer KS, Shamon M, Lee S,
Powers M. 1997 Annual Report of Am. Asso. of Poison Control
toxic exposure surveillance system. Am J Emerg Med 1998;
16:443-97.
10. Hawton K, Fagg J, Smikin S, Bale E, Bond A. trends in deliberate
self- harm in Oxford, 1985 1995 – implications for clinical services
and the prevention of suicide. Br J Psychiatry 1997; 171:556 560.
11. Sharma BR, Harish D, Singh G. Toxicological emergencies –
challenges to the health workers. Hospital Today 2003; 8(3): 117-
121.
12. Bayer MJ, McKay C. Advances in poison management. Clin Chem
1996; 42:8(B):1361-6.
13. Pillay VV. Comprehensive Medical Toxicology. 2
nd
Edition, 2008.
Paras Medical Publisher pp: 8-39.
14. Henry AH, Hoffman JR. Continuing controversy on gastric
decontamination. Lancet 1998; 352:420-21.
15. American Academy of Clinical Toxicology and European
Association of Toxicology Centers. Position Statement: single dose
activated charcoal. J Clin Toxicol Clin Toxicol 1997; 35: 721-41.
16. American Academy of Clinical Toxicology and European
Association of Toxicology Centers. Multiple dose activated charcoal.
J Clin Toxicol Clin Toxicol 1997;35: 711-9.
17. Arnold FJ, Hodges JB, Barta RA. Evaluation of efficacy of lavage
and induced emesis in treatment of salicylate poisoning. Paediatrics
1959; 23: 286-301.
18. Jones AL, Volans G. Management of self poisoning: recent
advances. BMJ 1999; 319: 1414-7.
19. Kulig W, Bar-Or D, Cantrill SV, Rosen P, Rumack B.
Management of acutely poisoned patients without gastric emptying.
Am J Emerg Med 1985; 14:562 -7.
20. Merigian KS, Woodard M, Hedges JR. Prospective evaluation of
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1990; 8: 479-83.
21. Holt LE, Holz PH. The black bottle. J Pediatr 1963; 63: 306-14. As
quoted by Bayer MJ, McKay C. in 12 above.
22. Neuvonen PJ, Olkkola, KT. Oral activated charcoal in the
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23. Rowden AM, Spoor JE, Bertino JS.The effect of activated
charcoal on Phenytoin pharmacokinetics. Ann Emerg Med 1990;
19: 1144-7.
24. Buckley N, Dawson A, Howarth D, Whyte I. Slow release
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25. Campbell J, Chyka P. Physiochemical characteristics of drugs and
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26. Everson G, Bertaccini E, O’Leary J. Use of whole bowel irrigation
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27. Janss GJ. Acute theophyliine overdose treated with whole bowel
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Protest against Vision 2015
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doc_407236884.pdf
Deaths due to poisoning are on the rise over the years, despite advanced knowledge regarding their pharmacokinetics and pathology, and newer and better techniques being developed for the management of poisoning cases.
J Indian Acad Forensic Med. Jan-Mar 2011, Vol. 33, No. 1 ISSN 0971-0973
74
Review Paper
Recent Advances in the Management of Poisoning Cases
*Dasari Harish, **K H Chavali,**Amandeep Singh, ** Ajay Kumar
Abstract
Deaths due to poisoning are on the rise over the years, despite advanced knowledge regarding
their pharmacokinetics and pathology, and newer and better techniques being developed for the
management of poisoning cases. The management of a poisoned patient has changed over the years.
Though the general principles of treatment of a poisoned patient remain the same, traditional methods
like gastric lavage, for example, have taken a back seat. There has been gaining popularity of newer
methods like use of activated charcoal and a variety of newer antidotes. Attention has also shifted to
toxidromes, the collection of symptoms and signs that consistently occur after ingestion of a particular
toxin or drug. Grouping the various signs and symptoms exhibited by a poisoned patient into different
toxidromes helps the physician in rapid identification of the toxidrome and saves time in evaluating and
managing a poisoned patient. However, the mainstay of the treatment, according to the experts is
stabilization of the patient.
Key Words: Poisoning, Poisoned Patient, Management, Gastric Lavage, Charcoal, Toxidromes
Introduction:
“All substances are poisons; there is
none that is not a poison;
The right dose differentiates a poison
from a remedy" – Paracelsus [1]
Poisoning and deaths due to poisoning
are on the rise over the years, despite advanced
knowledge regarding their pharmacokinetics and
pathology, and newer and better techniques
being developed for the management of
poisoning cases. It is estimated that there are
more than nine million synthetic and natural
chemicals available today.[2] In India, the trends
of poisoning have changed over the years, from
insecticides in the earlier times to fumigants, at
present.[3] The commonest agents in India are
the pesticides, followed by sedatives, drugs,
chemicals, alcohols, plant toxins and house-hold
cleansing agents.[4,5] Of late, aluminum
phosphide has emerged as the commonest
suicidal agent in Northern India.[6] In UK,
around 15-20% of workload of medical units is
due to self poisoning,[7] and paracetamol is one
of the commonest drugs involved in self-
poisoning, accounting for 43% of hospital
admissions with history of self-poisoning. [8]
Corresponding Author:
*Professor and Head,
Deptt. of Forensic Medicine & Toxicology,
Government Medical College & Hospital [GMCH],
Chandigarh
Email: [email protected]
** Assistant Professors, FMT, GMCH, Chandigarh
While in the US, it accounted for 4.1% of
deaths from poisoning.[9] The commonest agent
causing deaths in poisoning cases in the UK up
to 1998 was carbon monoxide.[10] The manner
of poisoning differs with the age and poisoning
in the paediatric age group generally occurs due
to accidental ingestion of commercial and
house-hold poisonous products (due generally
to curiosity), while in the adolescents and the
adults, intentional self poisoning is the common
mode.[11]
General Principles:
The general principles of management of
poisoning cases, as we know are:
1. Stabilization ? which includes assessment
and management of
a) The airway and Breathing
b) Circulation, and
c) Depression of the Central Nervous
System
2. Evaluation, if the patient is already stable
3. Decontamination ? including skin/ eye
decontamination, gut evacuation, etc
4. Poison Elimination ? diuresis, peritoneal/
haemo dialysis, haemoperfusion, etc
5. Antidote administration ? As of now,
antidotes are available for < 5% poisons
6. Nursing and Psychiatric care.
Now-a-days, stabilization of the patient
is being considered as the main stay of
management of poisoning emergencies.
Gastrointestinal evacuation, in use for centuries,
is undergoing critical appraisal. The role of
ipecac and gastric lavage are being questioned,
while activated charcoal is gaining importance in
the management of such cases. [12] Antidotal
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75
therapy is no more the mainstay of the
management and the fact that we have
antidotes for only about 5% poisons, is mainly
responsible for this development.[13] Grouping
the signs and symptoms produced by the
poisons in to various toxidromes helps in rapid
and effective management of the case.
Gastric Decontamination:
Interference with absorption of ingested
poison from the gastrointestinal tract is the
mainstay of poison management. Because few
specific antidotes are available to treat
poisonings, absorption prevention, observation,
and supportive care are the clinician’s greatest
assets. The challenge for clinicians managing
poisoned patients is to identify those who are
most at risk of developing serious complications
and who might potentially benefit from
gastrointestinal decontamination.[14] American
Academy of Clinical Toxicology and European
Association of Poison Centers & Clinical
Toxicologists gave the position statements in gut
decontamination in 1993. [15, 16]
Table 1: Summary of recommendations [15, 16]
Treatment Indications
Gastric
Lavage
Should not be considered unless a patient has
ingested a potentially life – threatening amount of a
poison and the procedure can be undertaken within
60 minutes of ingestion.
Activated
charcoal
May be considered if a patient has ingested a
potentially toxic amount of the poison (known to be
adsorbed by charcoal) up to 1 hour previously; there
are insufficient data to support or to exclude its use
after 1 hr of ingestion.
Ipecacuanha Its routine administration in the emergency
department should be abandoned; there are
insufficient data to support or to exclude its
administration soon after ingestion.
Whole–bowel
irrigation
May be considered for potentially toxic ingestion of
sustained release or enteric coated drugs; there are
insufficient data to support or to exclude its use for
potentially toxic ingestion of iron, lead, zinc, or
packet of illicit drugs (body – packer)
Cathartics The administration of a cathartic alone has no role
in the treatment of a poisoned patient and is not
recommended as a method of gut decontamination
a) Gastric Lavage:
Stomach emptying by gastric aspiration
and lavage has been in use in the management
of poisoning by ingestion, for almost 200 years.
[14] Studies, as early as 1959 [17] have
demonstrated that gastric lavage is no more
effective than ipecac emesis induced in specific
instance. Other investigators, however, have
challenged those studies on the basis of
improper technique as the studies were carried
out with animals and in non-overdose situations.
The effectiveness of both gastric lavage and
ipecac in removing stomach contents is time
dependent and best results are obtained when
performed within one hour. [12] Unfortunately,
many overdose patients do not arrive to the
emergency department within this valuable one
hour. Although emptying the stomach in the first
hour generally works [12, 18] and may be
beneficial for up to a certain period of time
thereafter, it is usually not helpful beyond 4
hours of ingestion. Sadly, the same is not
applied in our country. Irrespective of the time
gap, gastric lavage is performed in most of the
hospitals, as the initial part of the treatment.
Legal requirement, necessitating the
preservation of a sample of the return lavage
fluid for toxicological analysis, plays an
important role in the continuing use of this
technique, despite its efficacy being highly
questionable.
Gastric lavage carries potential
complications, including aspiration pneumonitis
and, rarely, esophageal perforation. It can also
promote the rapid passage of tablets into the
small bowel rather than removing them. Studies
have now shown that gastric lavage did not
prove any more beneficial than activated
charcoal, alone. [19, 20]
b) Activated Charcoal:
Activated charcoal has been used in the
treatment of poisonings since 1830, when its
effects were first demonstrated by the French
chemist Bertrand.[21] Produced by pyrolysis of
carbon containing materials and activated by
oxidation with steam at a high temperature,
these processed carbon products adsorb many
drugs. Most commercially available preparations
have a surface area of approximately 1000m
2
/g.
In addition to direct intra-luminal binding,
activated charcoal can also decrease the
resorption of agents that undergo enterohepatic
or enterogastric cycling. [22] It also has a
“gastrointestinal dialysis” effect, whereby the
charcoal serves as a large “sink” with movement
of toxin molecules across semi-permeable
membranes from splanchnic circulation. [23]
During the last decade, however,
activated charcoal became increasingly popular
as a first-line agent for the treatment of
poisonings, particularly if more than several
hours have passed since ingestion. It is
generally considered ineffective against
caustics, ethanol, ethylene glycol, methanol, iron
lithium, metals, and petroleum distillates. Usually
complications of its use are rare, but they
include aspiration of activated charcoal and
gastric contents, as well as intestinal
obstruction, particularly when repeated doses of
activated charcoal are given. [24]
The use of multiple-dose activated
charcoal (MDC) is now recommended for the
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76
clearance of drugs such as -- carbamazepine,
digitoxin, glutethimide, nadolol, phenobarbital,
phenylbutazone, theophylline, and others. [25]
Multiple dosing appears to decrease both the
absorption and blood concentration of many
drugs. The multiple-dose regimen consists of an
initial dose of 50-100g followed by maintenance
doses of 30-50 g every 2-6 h with or without the
administration of a cathartic agent. Maintaining a
constant amount of activated charcoal in the gut
adsorbs the toxin as it is secreted back in to the
gut, thereby preventing a delayed peak in the
serum concentration. [18]
When activated charcoal is continually
present in the gut, it might act as an infinite
“sink”, keeping the level of the toxin low in the
lumen of the gastrointestinal tract. As most of
the drugs and toxins are absorbed by simple
diffusion, this “sink” may reverse the normal
gradient, and actually permit transit of the toxin
out of the blood in to the lumen of the tract?
gastrointestinal dialysis. [23] This has been
shown to occur with theophylline,
carbamazepine, dapsone, quinine and
Phenobarbital.
Table 2: Charcoal & M D A
Substances not readily adsorbed to activated charcoal[18]
Ferrous salts Acids
Lithium preparations Alkalies
Potassium salts Fluorides
Ethanol Organic solvents
Methanol Mercury and its salts
Ethylene glycol Lead and its salts
Indications for multiple dose activated charcoal[18]
Slow release preparations such as theophylline (but not lithium)
Carbamazepine
Dapsone
Digoxin
Paraquat
Phenobarbitone
Quinine
Amanita phalloides
The Coordination Committee in Accident
and Emergency (A&E) Services of Hong Kong
Protocol advocates activated charcoal as the
treatment of choice for most poisons, except
metals, alcohol, cyanide, acids and alkalies,
which are not adsorbed by it.
c) Cathartics:
Catharsis actually means purification
and this is achieved in the poisoning cases by
purging the gastrointestinal tract of all the
poisonous material. This is the premise that
promotes their use for the rectal evacuation of
gastric contents - both the drug and the drug-
charcoal complex. Despite their widespread use,
however, little evidence exists that cathartics
alter the outcome of poisoned patients. The
most commonly used cathartics are magnesium
sulfate, magnesium citrate, and sorbitol. Sorbitol
works the most quickly; causing bowel
movements within one hour.[12]
Contraindications to cathartics include caustic
ingestions and signs of intestinal obstruction. If
being considered, one dose is generally
sufficient.
d) Whole - Bowel Irrigation:
Polyethylene glycol-electrolyte solutions,
which once were used for bowel cleansing
before surgical procedures, are now being
applied for gastrointestinal decontamination.
These iso-osmotically balanced, non-absorbable
solutions are safe, causing no fluid retention or
electrolyte disturbances.[26] The procedure has
been advocated for overdoses of agents such as
iron, lithium, arsenic, lead-oxide and enteric-
coated or sustained-release medications. In
practice, hemodynamically stable and
cooperative patients are best suited for this
intensive cathartic treatment. [24, 27] Adults
should be given the solution at a rate of 2 L/h,
children at 500 ml/h, either orally or through a
naso-gastric tube. The endpoint of treatment is
a clear effluent, which may take 4-6 hours to
appear. Contraindications include ileus or bowel
obstruction, hemodynamic instability or where
airway cannot be protected. [28]
e) Emesis:
Ipecac syrup has long been used as a
first-line agent for prevention of toxicity from
ingested poisons, especially in children.
However, this is not freely available in our
country [13] and its effectiveness in recovering
ingested substances is poor, and its ability to
reduce the severity of poisoning has never been
demonstrated. Moreover, the emesis induced by
ipecac may preclude the use of other oral
treatment options. [29] It is contraindicated in
ingestion of caustic substances and volatile
hydrocarbons, in patients who have decreased
gag reflex or altered mental status, and in
patients at risk for rapid alteration in
consciousness. Complications of ipecac include
aspiration pneumonia, lethargy, diaphragmatic
rupture, Mallory-Weiss esophageal tears and
cerebral hemorrhages.[30] Ipecac is also still
recommended by poison control centers for use
in the home, where early administration can be
assured.
Laboratory Tests:
Although laboratory analysis of various
body fluids of overdose patients frequently
identifies substances that are clinically
unsuspected, these additional findings rarely
alter the patient’s clinical course, largely
because the presence of a substance does not
necessarily correlate with acute toxicity;
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77
moreover, analysis can be time-consuming and
in most clinical settings falls short of being
comprehensive.[12] Most poisoned or overdose
patients do well with supportive care alone.
Again, no rapidly available universal screening
tool exists and many patients require little, if any,
laboratory investigation.
Rational use of Antidotes:
Antidotes are chemical or physiological
antagonists that prevent the toxicological effect
of specific poisons. In most toxicological
emergencies, effective antidotes are not
available. Symptomatic treatment and
supportive care are still the primary approach to
treatment; antidotal therapy often plays a
relatively minor role. When appropriately used
in specific situations, however, antidotes can
substantially reduce morbidity and mortality in
the poisoned patient.
Some Newer Antidotes:
a) Hydroxycobalamin: [31] It is the synthetic
form of vitamin B
12
and is given in cases of
cyanide poisoning presenting with
hypotension, where the conventional
antidote sodium nitrite is contraindicated. It
works by sequestering cyanide from the
plasma-cyanide to give non-toxic
cyanocobalamin. The only adverse effects
are brown discoloration of the body fluids,
nausea and vomiting. The recommended
dose is 5g) of the reconstituted solution over
30 minutes.
b) Digoxin specific antibodies (Fab
antibodies): [32] Digoxin specific antigen
binding fragments are indicated in life
threatening arrhythmia/hyperkalaemia
caused by intoxication with cardiac
glycosides. As the antibodies are produced
in sheep, monitoring for anaphylaxis and
serum sickness is necessary.
c) Esmolol hydrochloride: [32] It is a short
acting cardioselective beta- adrenoceptor
blocking drug that has no sympathomimetic
activity. It is used to control hypertension
and tachyarrythmia due to poisoning by
sympathomimetic drugs.
d) Octreotide: [32] A synthetic polypeptide that
antagonizes pancreatic insulin release, it is
indicated in overdose of insulin or oral
hypoglycemic agents, mainly sulphonylurea.
e) Succimer (2,3dimercaptosuccinicacid):
[33] it is a chelating agent used for the
treatment of lead, mercury and arsenic
poisoning. It is the water soluble analogue of
dimercaprol and can be taken orally.
f) Fomepizole (4-methypyrazol): [33] It is a
potent competitive inhibitor of alcohol
dehydrogenase and prevents the formation
of toxic metabolites following methanol and
ethylene glycol poisoning. It is now preferred
to ethanol as the antidote as it does not
cause sedation.
g) Nalmefene and Naltrexone: [33] they are
long acting opioid antagonists and are used
to manage opioid dependence. They are
more potent than Nalaxone but are much
more expensive.
Toxidromes:
The term was first coined by Mofenson
and Greensher. [34] They are a collection of
symptoms and signs that consistently occur after
ingestion of a particular toxin or drug and can
often be identified with a basic history & physical
examination. Many physicians now group the
various signs and symptoms of the poisons into
different toxidromes as the rapid identification of
the toxidrome saves time in evaluating and
managing a poisoned patient. The various
toxidromes are anticholinergic, cholinergic,
sympathomimetic (adrenergic), opiod and
sedatve-hypnotic. Each of these toxidromes has
specific signs and symptoms and requires a set
pattern of management. Hence even if the
poison cannot be identified, it can be classified
into one of the above syndromes based on the
signs and symptoms exhibited and appropriate
treatment can be initiated.
Conclusion:
There has been a major change in the
treatment of poisoned patients, particularly in the
area of gastric decontamination. The trend is
away from the use of ipecac, except in limited
situations such as accidental ingestions in
pediatric patients. For that reason, activated
charcoal has attained a prominent role, not only
as an adjunct for gastric emptying with either
ipecac or gastric lavage but also for use as the
sole decontamination agent. Gastric lavage still
plays an important role, especially if it can be
performed early, or if drugs are involved that
may delay gastric emptying. Whole–bowel
irrigation is safe and effective in limited
situations such as iron, lithium, or sustained-
release medications, and for body packers.
Antidotes play an important role in specific
situations. Oxygen is extremely useful for the
treatment of CO. Naloxone is useful for the
treatment of opiate intoxication. Fab fragment
antibodies are safe and effective for the
treatment of digitalis intoxication. Despite the
advances in gastric decontamination and the
development of new antidotes, the mainstay of
treatment for the poisoning victim remains
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78
supportive care and frequent re-evaluation for a
change in clinical status.
Table 3: Common Toxidromes: Signs and Symptoms [35]
Physical findings Adregenic
Toxidrome
(decongest.,
amphetamine,
cocaine)
Anticholinergic
Toxidrome (antihist.,
phenothiazine)
Cholinergic Toxidrome
(Insecticides)
Opiod Toxidrome Sedative-hypnotic
Toxidrome
(tranquilizer,
barbiturates,
ethanol)
Vital Signs
Resp. Rate Increased No change Increased/ no change Decreased Normal/ decreased
Heart rate Increased Increased Decreased Normal/ decreased Normal
Temperature Increased Increased No change Normal/ decreased Normal
Blood P Increased Increased/ no change No change Normal/ decreased Normal
Physical Examination
Mental status Alert/ agitated Depressed/ confused/
hallucinati ng
Depressed/ confused Depressed Depressed
Pupils Dilated Dilated Constricted Constricted Normal
Mucous membranes Wet Dry Wet Normal Normal
Skin Diaphoretic Dry Diaphoretic Normal Normal
Reflexes Increased Normal Normal/ decreased Normal/ decreased Normal/ decreased
Bowel sounds Increased Decreased Increased Decreased Normal
Urination Increased Decreased Increased Decreased Normal
Other Possible seizures Possible seizures Musclefasciculations
/possibe seizures
-- --
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