POISONING (TOXICOLOGY)

Bimel kottarathil

A poison is any substance that causes harm if it gets into the body. . Almost any chemical can be a poison if there is enough in the body.

POISON

The amount of a chemical substance that gets into the body at one time is called the dose.

DOSE

Depends upon availability and culture Uk –paracetamol is a problem Srilanka –pesticides South india –copper sulphate

INCIDENCE

Acute exposure Chronic exposure

EXPOSURE TO A POISON

Through mouth by swallowing Through lungs by breathing Contact Through skin Injection through skin

ROUTE OF ABSORPTION

Most common route Children are commonly involved Can be accidental or deliberate Eg. Pesticide poisoning

swallowing

Gas, vapour, dust Fine spray or droplet Poison enters to lungs and then spread

across the whole body Eg. carbon monoxide

INHALATION

chemical is sprayed or splashed onto the skin

if they wear clothes soaked with chemical. E.g. pesticide

THROUGH SKIN BY CONTACT

Poisons can be injected through the skin from a syringe or a pressure gun

During tattooing The bite or sting of a poisonous animal,

insect, fish or snake.

By injection through the skin

DRUGS ,OTHER CHEMICALS Ethylene glycol Methanol Amphetamine Anticonvulsants Corrosives Anti diabetic drugs Antimalarials Batteries Benzodiazepines

SPECIFIC POISONS

Calcium channel blockers Insecticide Carbon monoxide Cocaine Cyanide Digoxin House hold products Nail polish Heavy metal poisoning Organophosphorous poisoning

Contd…

Antidepressants Acetaminophen NSAID Antipsychotics Methyl xanthine Theophylline Snakes

Contd…

Ethylene glycol is a sweet-tasting substance that is a common constituent of antifreeze.

ETHYLENE GLYCOL

The clinical course of ethylene glycol intoxication can be divided into three phases

The first phase The first phase occurs less than 1 h after

ingestion and is characterized by mental status depression, similar to that of alcohol intoxication ,coma ,seizurs, and respiratory depression

Symptomatology

Second phase Cardio pulmonary toxicity Acidosis ,heart failure and pulmonary

oedema Final stage Flank pain Acute tubular necrosis Hypocalcaemia Renal toxicity due to calcium oxalate

Air way support Circulatory support Correction of metabolic abnormalities Control of seizures Bicarbonate to correct acidosis Fomepizole is the new antidote by FDA Haemodialysis

TREATMENT

Industrial alcohol Toxic alcohol Used in antifreeze,paint,thinner rubbing

alcohol

MENTHOL

Oxidised to formaldehyde then to formate Formate produces toxic effect and acidosis

TOXICITY

Cns depression Head ache Lethargy Convulsions Delirium Coma

Ocular symptoms

Photophobia Central scotoma (loss of central vision ) Visual field defects Fixed pupils

SYMPTOMATOLOGY

Difficuilty in light adaptation Optic disc oedema Optic atrophyOther symptoms Nausea ,vomiting ,diaphoresis ,abdominal

pain (due to pancreatitis)

Contd

airway protec tion circulatory support correction of metabolic abnorm alities control of seizures. ethanol and fomepizole for specific

treatment Hemodialysis

TREATMENT

commonly known as ecstasy drug or party drug, has been abused world-wide.

Amphetamines are CNS and cardiovascular stimulants

AMFETAMINES INCLUDING ECSTASY (MDMA)

Euphoria, extrovert behavior, lack of desire to eat or sleep, tremor, dilated pupils, tachycardia and hypertension

Severe intoxication Agitation, paranoid delusions, hallucinations

and violent behavior. Convulsions, rhabdomyolysis, hyperthermia and cardiac arrhythmias

Intracerebral and subarachnoid Hemorrhage(rare)

Clinical features

Base line support Agitation is controlled by diazepam 10-20

mg i.v. chlorpromazine 50-100 mg i.m. injection

Treatment

Carbamazepine. Phenytoin. Sodium valproate. Gabapentin. Lamotrigine Topiramaie

ANTICONVULSANTS

Drowsiness, respiratory depression,loss of consciousness, moclonic jerks, seizurs

Lethargy, ataxia, slurred speech, nystagmus Posturing, agitation ,hallucinations

MANIFESTATIONS

charcoal 50-100 g oral Hemodialysis

Management

Corrosive agents: Acids: hydrochloric acid, sulfuric acid,

hydrofluoric acid Alkali: sodium hydroxide, potassium

hydroxide, ammonia, sodium hypochlorite Other: zinc chloride, mercuric chloride,,

phenols, potassium permanganate, button batteries

CORROSIVES

Do not put NGT Acid exposure is life threatening Maintain ABC Specific antidots given to nutralise acid or

alkali Sodium bi carbonate in acid poisoning Soda ,lemon juice ammonia in alkali

poisoning

MANAGEMENT

Insulin Sulfonylurea

ANTIDIABETIC AGENTS

drowsiness, coma, twitching, convulsion depressed limb reflexes,apnea, pulmonary oedema, tachycardia and hypoglycemia

Clinical features

Ensure plasma glucose concentration Intra venous glucose Glucogon is also used Maintatanance with continuous glucose

infusion with kcl

Treatment

Chloroquine. Quinine.

ANTI MALARIALS

Hypotension acute heart failure, pulmonary oedema and

cardiac arrest. Agitation and acute psychosis, convulsions and coma Brady arrhythmias and tachyarrhythmia's are common and ECG conduction abnormalities are similar to those seen in quinine poisoning (QT prolongation)

tinnitus, deafness, vertigo, nausea, headache and diarrhea

MANIFESTATIONS

Common suicidal agents Rarely produce severe poisoning Mostly in elderly with respiratory disease

BENZODIAZEPINES

drowsiness, ataxia, dysarthria nystagmus. Coma respiratory depression

Clinical features

Respiratory depression is managed by Airway support

Flumanezenil 0.5-1.0 mg iv is the drug of choice

Treatment

act by blocking voltage-gated calcium channels, Overdose of these drugs, particularly with verapamil and diltiazem, are serious with heart block and hypotension causing a significant fatality rate.

CALCIUM CHANNEL BLOCKERS

Hypotension Myocardial depression Conduction block Sinus bradycardia Heart block Pulmonary oedema Nausea Vomiting Seizures Lactic acidosis

Clinical features

Activated charcoal Intravenous hypotension with intravenous

crystalloid Iv glucagon Dopamine to treat hypotension

Treatment

Carbonate insecticides inhibit acetyl cholinesterase

this effect is comparatively short-lived,and milder

similar to Organophosphorous poisoning Atropine is the drug of choice

CARBAMATE INSECTICIDES

The commonest source of carbon monoxide is an improperly maintained and poor, ventilated heating system. The affinity of hemoglobin for carbon monoxide is some 240 times greater than that for oxygen. Carbon monoxide combines with hemoglobin to form carboxyhaemoglobin

Carbon monoxide

Symptoms of mild to moderate exposure to carbon monox ide may be mistaken for a viral illness

In headache and mild exertional dyspnoea Higher concentrations of COHB are

associated with coma, convulsions and cardio respiratory arrest

Clinical features

High flow oxygen Et intubation and mechanical ventillation

Treatment

Assess airway and breathing Intubations Primary intervention Oxygen administration Intubation Subsequent assessment History,determine, LOC ,asses complaints Vital signs , look for rales or wheezes

Nursing management

Cocaine hydrochloride ('street' cocaine, 'coke') is a water-soluble powder or granule that can be taken orally, intrave nously or intranasally.

COCAINE

Initial euphoria, agitation, tachycardia, hypertension, sweating, hallucinations, convulsions ,metabolic acidosis, hyperthermia, rhabdomyolysis, ventricular arrhythmias. Dissection of the aorta, Myocarditis, myocardial infarction, dilated cardiomyopathy, subarachnoid Hemorrhage, and cerebral Hemorrhage

Clinical features

Diazepam 10 mg iv to control agitation Active cooling Phentolamine 2-5 mg iv for hypertension

Primary assessment and interventions Subsequent assessment General interventions

Nursing management

Cyanide reversibly inhibits cytochrome oxidase a3 so that cellular respiration ceases. Cyanide and its derivatives are used widely in industry

CYANIDE

Chest tightness Dyspnoea Coma Convulsion Metabolic acidosis

Clinical featurs

Support ABC Dicobalt edetate Sodium thiosulphate hydroxocobalamin

Treatment

Toxicity occurring during chronic administration is common, though acute poisoning is infrequent

Digoxin

nausea, vomiting, dizziness, anorexia and drowsiness. Rarely, confusion, visual disturbances and hallucinations

SVT with or without heart block VPC hyperkalemia

Atropine Digoxin –fab –specific antibody to

neutralise Digoxin

Treatment

bleach, cosmetics, toiletries, detergents, disinfectants and petroleum distillate

Management Symptomatic

HOUSEHOLD PRODUCTS

Arsenic Mercury Cadmium Iron Aluminium Lead

HEAVY METAL POISONING

Arsenic is the most common cause of acute heavy metal poisoning in adults

Arsenic

Symptoms of acute exposure are cough, sore throat, and shortness of breath; metallic taste in the mouth, abdominal pain, nausea, vomiting and diarrhea; headaches, weakness, visual disturbances, tachycardia, and hypertension.

Mercury

It is used in nickel-cadmium batteries chronic exposure could include alopecia,

anemia, arthritis, learning disorders, migraines, growth impairment, emphysema, osteoporosis, loss of taste and smell, poor appetite, and cardiovascular disease

Cadmium

most of the toxic effects of iron occurs because iron is absorbed rapidly in the gastrointestinal tractMost overdoses appear to be the result of children mistaking red-coated ferrous sulfate tablets or adult multivitamin preparations for candy

Iron

Although aluminum is not a heavy metal Symptoms of aluminum toxicity include memory loss, learning difficulty, loss of coordination, disorientation, mental confusion, colic, heartburn, flatulence, and headaches

Aluminum

Lead accounts for most of the cases of pediatric heavy metal poisoning. It is a very soft metal and was used in pipes, drains, and soldering materials for many years. Target organs are the bones, brain, blood, kidneys, and thyroid gland exposure to lead occurs occupationally

Lead

abdominal pain-vomiting, constipation and encephalopathy (seizures, delir ium, and coma) may develop in more severe cases.

Clinical features

chelation therapy sodium calcium acetate 75 mg/kg/day

has been the chelating agent of choice

Treatment

Organophosphorous insecticides are used widely throughout the world and are a common cause of poisoning, causing thousands of deaths, in the developing world

ORGANOPHOSPHORUS INSECTICIDES

anxiety, restlessness, tired ness, headache, and muscarinic features such as nausea, vomiting, abdominal colic, diarrhoea, tenesmus, sweating, hypersalivation and chest tightness.

intermediate syndrome

Clinical features

Support ABC Gastric lavage Activated charcol Atropine 2 mg i.v. Should be given to

reduce pulmonary oedema

Treatment

Tricyclic antidepressants (TCAS) are potentially lethal in overdose. TCA agents act on multiple receptor sites. Their principal antidepressant action is mediated by serotonin and noradrenalin re-uptake inhibition.

ANTIDEPRESSANT TOXICITY

Anticholinergic effects Agitation, delirium Dilated pupils Dry, warm, flushed skin Tachycardia Urinary retention Neurotoxicity Sedation Seizures Coma

Clinical featurs

Cardiotoxicity Tachycardia Hypotension Broad complex arrhythmias Bradycardia (late) Ecg changes Prolonged pr, qrs and qt interval

Contd…

Within a few hours of acetaminophen overdose, typical symptoms include nausea and vomiting. Tenderness and pain in the upper right abdomen may be present.

Very large doses can result in lactic acidosis (a drop in pH of the blood) and coma

ACETAMINOPHEN AND NSAID TOXICITY

NSAID use is associated with significant adverse effects such as gastrointestinal bleeding, peptic ulcer disease, high blood pressure, edema (i.e., swelling), and kidney disease

NSAIDS

combine with gastro protective agents H2 receptor antagonist Ppi inhibiters Nutritional Support Antioxidents

Prevention

Dopamine receptorsSerotonin receptorsMuscarinic receptorsAlpha adrenargic receptorsHistamine receptors

Antipsychotics

The methylxanthines theobromine and caffeine can be found in a variety of substances (e.g., chocolate, cocoaand coffee beans, over-the-countersleep prevention aids, asthma medications [theophylline, aminophylline]).

METHYL XANTHINE

vomiting, diarrhea, polyuria, polydipsia, hyperactivity, ataxia, tachycardia,tachypnea, hypertension, weakness,cardiac arrhythmias, tremors, seizures,coma, and death

Manifestations

Emesis Activated charcol Supportive management

Management

Theophylline has been widely prescribed for the management of patients with chronic obstructive lung disease and asthma. Despite declining use over recent years,

THEOPHYLLINE

Agitation, hyperventilation, headache, convulsions Arrhythmiasnausea & vomiting (may be intractable), thirst, diarrhoea

Manifestations

Asymptomatic Charcoal 1g/kg Observe 4 hours. If no

symptoms, discharge if not slow release medication .If ingestion of slow release preparation, admit for observation and serial drug levels

Management

Symptomatic Charcoal 1g/kg initially unless altered

conscious state (protect airway first) then 0.5g/kg 4 hourly, and whole bowel irrigation with colonic lavage solution 30ml/kg/hr.Cardiac monitoringI.V. fluid resuscitation & maintenance of adequate hydration is vital if depressed conscious state, arrhythmias or intractable vomiting may need intubation

Contd…

Features Likely poisons

Constricted pupils(miosis) Opioids, organophosphorus insecticides, nerve agents

dilated pupils

(mydriasis)

Tricyclic antidepressants, amfetamines, cocaine, antimuscarinic drugs

Divergent strabismus Tricyclic antidepressants

Nystagmus Carbamazepine, phenytoin

Loss of vision Methanol, quinine

Papilledema Carbon monoxide, methanol

Convulsions Tricyclic antidepressants, theophylline, opioids, mefenamic acid, isoniazid, amfetamines

CLINICAL MANIFESTATIONS OF POISONING

Features Likely poisons

Dystonic reactions Metoclopramide, phenothiazines

Delirium and hallucinations Amfetamines, antimuscarinic drugs, cannabis, recovery from tricyclic antidepressant poisoning

Hypertonia and hyper reflexia Tricyclic anti depressants

Tinitus and deafness Salicilates

Hyperthermia Salicilates ecstasy drugs

Contd…

. POISON ABSORPTION Gut decontamination Gastric lavage.. Induce vomiting Single-dose activated charcoal Cathartics Whole bowel irrigation

GENERAL MANAGEMENT

Muiti-dose activated charcoal (mdac) Urine alkainization. Hemodialysis

INCREASING POISON ELIMINATION

Poison Antidote

Aluminum (aluminum) Desferrioxamine (deferoxamine)

Arsenic Dmsa,(dimercaptosuccinic acid)

Benzodiazepines Flumazenil

Beta -adrenoceptor blocking drugs Atropine, glucagon

Calcium channel blockers Atropine

Carbamate insecticides Atropine

carbon monoxide Oxygen

Copper D-penicillamine, dmps1

Specific management

Poison Antidote

Opioids Naloxone

Organophosphorus insecticides atropine, hi-6, obidoxime,pralidoxime

paracetamol (n-acetylcysteine)

Thallium Berlin (prussian) blue

Warfarin and other anticoagulants Phytomenadione (vitamin k)

Contd…

Thank you