toixicity

Question 1

coma treatment

Answer 1

Coma is normally associated with ingestion of large doses of
antihistamines (e.g diphenhydramine), benzodiazepines, ethanol,
opioids, antipsychotics or antidepressants.

The most common cause of death in comatose patient is respiratory
failure. Pulmonary aspiration of gastric contents and hypoglycemia may
also occur. Hypoxia and hypoventilation may cause hypotension.
Treatment:
Establish a patent airway by positioning or suction.

Dextrose solution infusion, naloxon 0.4 to 2mg intravenlously reverse
opioid induced respiratory depression, Flumazenil 0.2 to 0.5mg
intravenously for benzodiazepines.

Question 2

hypothermia

Answer 2

Hypothermia occur due to hypoglycemic agents, opioids,
phenothiazines, sedative-hypnotics.

Hypothermia may cause hypotension.

Treatment:

rewarming, intravenous infusion of synthetic prostaglandins

Question 3

Hypertension

Answer 3

It may be due to poisoning with amphetamines, anti-cholinergics,
cocaine, caffeine, phenylephrine, ephedrine, MAOI etc.

This may result in intracranial haemmorage, myocardial infarction.

Treatment:

lorazepam 2-3mg intravenously, for persistant hypertension
phentolamine2-5mg intravenously.

Question 4

SEIZURES

Answer 4

Seizures may be due to poisoning with amphetamine, antidepressants,
antihistamine, antipsychotics, isoniazid, chlorinated insecticide,
tramadol, theophylline etc.

Seizure may also be caused by hypoxia, hypoglycemia, hypocalcemia,
withdrawal from alcohol.

Treatment:

lorazepam 2-3mg or diazepam 5-10mg intravenously.

Question 5

HYPERTHERMIA

Answer 5

It is associated with atropine, amphetamine, anti-cholinergics,
salicylates, strychnine, antipsychotics, SSRI etc.

Treatment:

removing excessive clothing, spraying skin with water, Dantrolene
2-5mg/kg intravenously

Question 6

Non specific

Answer 6

Emesis
IPECAC SYRUP TO CONSCIOUS
APOMORPHINE TO NONCONSCIOUS

2. Gastric lavage: Tape water or normal saline solution
3. Adsorption therapy: Activated charcoal

Specific treatment/antidote

Acetaminophen

n ACETYL CYSTEINE
GLUTATHIONE

Amphetamine and cocaine
seizures, hyperthermia, tachychardia

Arsenic/heavy metal poisoning

Dimarcaprol
Atropine and anticholinesterases
prolidoxime /physiostigmine

Aspirin
Sdoium bicarbonate infusion

Question 7

Treatment of poisoning

Answer 7

1. To decrease the absorption and distribution of toxicant
2. To increase the threshold level of toxicity
3. To increase the excretion of toxicant from the body

Question 8

Lethal dose

Median lethal dose or LD50:

Therapeutic index

ratio

Answer 8

it is the lowest dose that causes death in any animal during
the period of observation.

Median lethal dose or LD50: It is a dose that is lethal to 50 percent of
the animal exposed to a specific toxicant under defined conditions like
species, route of exposure and duration of exposure. It is commonly
used measure of toxicity.

Therapeutic index: it is defined as the ratio of LD50 to ED50.

Therapeutic ratio: ratio of the LD25 to ED75.

Question 9

classificaiton of toxicity

Answer 9

Toxic effects:

These are undesirable effects produced by a toxicant/drug.
Side effects : these are undesirable effects which result from the normal
pharmacological actions of a drug.

Toxicity depending upon exposure is classified as:

Acute toxicity: produced by single dose or multiple doses during 24hour
period

Sub acute: it is the study of repeated exposure of a toxicant and its effects for
30 days or less.

Sub chronic toxicity: it is the study of repeated exposure of a toxicant and its
effects for 1 to three months.

Chronic toxicity: it is the study of repeated exposure of a toxicant and its
effects for 3 months or more.