Poisons

Question 1

Name 6 methods of poisoning decontamination

Answer 1

1. Forced emesis, 2. Gastric lavage, 3. Adsorption (charcoal), 4. Whole bowel irrigation, 5. Catharsis (shortening gut transit time using sorbitol & charcoal). 6. ENHANCED ELIMINATION

Question 2

Complications of forced emesis

Answer 2

Aspiration and further damage eg from corrosives

Question 3

Complications of gastric lavage

Answer 3

Risk of flushing into bowel & incr absorption. Perforation.

Question 4

Most effective time from ingestion for activated charcoal

Answer 4

1 hr

Question 5

Why does activated charcoal not work with metals (lithium, iron etc.)?

Answer 5

They do not bind to it.

Question 6

Why does activated charcoal not work with hydrocarbons, (ethanol, methanol etc.)?

Answer 6

They are absorbed too rapidly .

Question 7

Contraindications for charcoal

Answer 7

Caustic substances - danger of charcoal induced vomiting.

Question 8

Methionine is strongly or weakly adsorbed by charcoal?

Answer 8

Strongly adsorbed

Question 9

What are 3 methods of enhanced elimination?

Answer 9

1. Urine alkalinisation, 2. Forced diuresis, 3. Heamodialysis / haemoperfusion

Question 10

Briefly outline Urine alkalinisation

Answer 10

Keeping urine at ph7-8. Prevents weak acids e.g. aspirin becoming lipid soluble so they flush out in urine not into cells.

Question 11

Briefly outline Forced diuresis

Answer 11

Giving diuretic eg furosemide (often in combin with urine alkalinisation)

Question 12

Briefly outline heamoperfusion

Answer 12

Passing blood through charcoal - but oral charcoal simpler and can be as effective

Question 13

What 6 effects common to these drugs in overdose:

TCAs, Antihisthamines, Orphenadrine (Parkinson’s med.), Thioridazine (antpsychotic)

Answer 13

Coma, hypertonia, extensor plantar reflexes, myoclonus (twitching), mydriasis (dilated pupils), sinus tachycardia (prol. QT - TCAs and antipsych.))

Question 14

What might cause: coma, miosis (constrict. pupils) and red. resp rate?

Answer 14

Opiates

Question 15

Antidote for opiates?

Answer 15

Naloxone

Question 16

Nausea & vom.
Tinnitus, Metabolic acidosis
Deafness, Vasodilation
Sweating, Hyperventilation

Answer 16

Salicylates (e.g. aspirin)

Question 17

What 3 drugs might cause:
Coma, hypotonia & hyporeflexia
Hypotension
Extensor or absent plantar response.

Answer 17

Benzodiazepines +-alcohol
Barbituates (eg Sodium thiopental)
Severe TCAs

Question 18

Hyperthermia, Tachycardia, delirium, mydriasis, agitation

Answer 18

MDMA (ecstasy - amphetamine)

Question 19

Paracetamol antidote

Answer 19

N-acetyl cysteine

Question 20

Benzodiazepine antid.

Answer 20

Flumazenil

Question 21

Beta blocker antid.

Answer 21

Glucagon

Question 22

Iron antid.

Answer 22

Desferrioxamine

Question 23

Paraquat antid.

Answer 23

Fullers earth

Question 24

Methanol antid.

Answer 24

Ethanol

Question 25

Digoxin antid.

Answer 25

Digoxin specific antibiodies

Question 26

TCA od treatment

Answer 26

Supportive and activated charcoal

Question 27

What dose of paracetamol may be toxic?

Answer 27

10-15g within 24 hrs can kill

Question 28

Outline pathophsyiology of paracetamol poisoning

Answer 28

5-10% forms toxic metabolite - NAPQI. Normally this conjugated with Glutathione & excr by kidneys. In OD glutathione stores empty - NAPQI binds to liver cells - necrosis.

Question 29

Paracetamol OD treatment regime?

Answer 29

``` Charcoal within 1 hr Serum levels measure at 4 hrs. Start N acetyl cisteine btwn 4 - 8 hrs Reduced effectiveness >8hrs Methionine also a glutathione precursor ```

Question 30

Features of paracetamol OD (6)

Answer 30

``` Vomiting Abd pain Hyper / hypo glycaemia Metabolic acidosis Jaundice / encephalopathy Renal failure ```

Question 31

Carbon monoxide poisoning features? (6)

Answer 31

``` Headache Nausea & vom Weakness Altered LOC Cherry red lips Tachycardia CNS abnormalities ```

Question 32

Carbon monoxide treatment?

Answer 32

Oxygen (hyperbaric O2 for severe and pregnancy)

Question 33

``` What might cause: Anxiety Dizziness Dyspnoea Reduced LOC Tachycardia or bradycardia "Bitter almonds" smell Acidodic - no signs of hypoxia ```

Answer 33

Cyanide (industrial uses, burning wool, plastics)

Question 34

``` What is treated with: 100% oxygen Dicobalt edetate (Kelocyanor) Vit B12 Nitrites & sodium thiosulphate ```

Answer 34

Cyanide

Question 35

Digoxin toxicity SE

Answer 35

Xanthopsia - things look yellow Dysryhthmias Nasea & vomiting