Toxicology - general Flashcards
In the unconscious patient, which specific agents should be investigated with drug levels?
Carbamazepine
Ethanol
Salicylate
Sodium Valproate
Describe the enhanced elimination strategy for carbamazepine
Multidose activated charcoal
Haemodialysis
Describe the enhanced elimination strategy for phenobarbitone
Multidose activated charcoal
Haemodialysis
Describe the enhanced elimination strategy for Salicylate poisoning
Urinary alkalinisation
Haemodialysis
Describe the enhanced elimination and antidote strategy for toxic alcohols
Ethanol
Haemodialysis
Describe the enhanced elimination strategy for Sodium valproate
Haemodialysis
Antidote for isoniazid
Pyridoxine 1g per g of isoniazid up to 5g (70 mg/kg in children), as slow IV infusion 0.5g / min until seizures stop, then remainder (if any) over 4 hrs
Antidote for organophosphate poisoning
Atropine 1.2mg (50mcg/kg) IV Q5min double dose until dry
Pralidoxime 2g IV and then infusion 0.5g/hr (controversial)
Management of VT due to sodium channel blockade?
What medication to avoid?
Intubation, hyperventilation
Bolus IV NaHCO3 1-2 mmol/kg IV Q1-2 min
NO AMIODARONE
When pH >7.5, IV lignocaine 1.5 mg/kg then infusion 2mg/min
Management of tachycardia or acute coronary syndrome in setting of sympathomimmetic use
IV diazepam 5-10mg Q2-5min until
4 categories of agents causing corrosive injury to the oropharynx which can result in airway compromise
Alkalis
Acids
Glyphosate
Paraquat
Antidote in carbamate poisoning
Atropine 20-50 mcg/kg (1.2mg) IV Q5min doubling dose until dry
Toxicological cause of hypocalcaemia
Hydrofluoric acid ingestion
Extensive cutaneous burns
Management of VF due to hypocalcaemia
IV calcium gluconate 10% 60 to 90 mls IV bolus, repeated Q2min until defibrillation successful
How do you undertake high dose insulin therapy?
High dose insulin therapy
- glucose 50% 50 mls IV bolus
- short acting Insulin 1 unit/kg IV bolus
Then
- glucose 25g/hr IV infusion via CVC titrate to euglycaemia
- Short acting insulin 0.5 units/kg/hr IV, increased to 1-2 units/kg/hr
Management of SVT due to theophylline toxicity
IV beta-blocker titrate to effect
Urgent haemodialysis
Management of calcium channel blocker toxicity
IV calcium gluconate 10% 60-90 mls
High dose insulin therapy
Agents causing fast sodium channel blockade
TCA 1A antiarrhythmics 1C antiarrhythmic II antiarrhythmic: diltiazem IV: propranolol Local anaesthetic Hydroxychloroquine, chloroquine Quinine Dextropropoxyphene Amantadine Carbamazepine
Agents causing prolonged QT
Antipsychotics 1A antiarrhythmic 1C antiarrhythmic III: sotolol TCAs Antidepressants: escitalopram/citalopram, MAOI Antihistamines Chloroquine, hydroxychloroquine Quinine Fluroquinolones: moxifloxacin Macrolides: azithromycin, erythromycin Methadone
Causes of high osmolar gap
Acetone Ethanol Ethylene glycol Methanol Isopropyl alcohol Propylene glycol Mannitol Non-toxicological: DKA, CRF, hyperlipid/protein, lactic acidosis, trauma/burns, shock
Causes HAGMA
HAGMA Carbon monoxide, cyanide Alcohol, alcoholic ketosis Toulene Metformin Uraemia DKA Paracetamol, paraldehyde, prolylene glycol Isoniazid, iron Lactic acidosis Ethylene glycol Salicylate, starvation ketosis
Causes of NAGMA
RACE Renal: RTA, addisons Acetazolamide Chloride excess Extra loss: diarrhoea, fistula (pancreatic, small bowel, ureterostomy etc)
Causes metabolic alkalosis
CLEVER PD Contraction of volume (dehydration) Liquorice Endocrine - conn's, cushings Vomiting, GI loss Excess alkali - bicarb, antiacid, calcium Renal - barters, gitleman Post hypercapnoea Diuretic
Agents requiring lower treatment threshold in pregnancy patients due to increased risk to foetus
Carbon monoxide
Methaemoglobinaemia induicing agents
Lead
Salicylate
Tablets and poisons lethal to 10kg child in 1-2 tablets
A Baby Could Collapse Very Dead Over Picking Some Theophylline Tablets, Now Other Poisons Can Have Same Catastrophe. Amphetamine Baclofen Calcium channel blocker, carbamazepine, chloroquine Clozapine Venlafaxine Dextropropoxyphene Opioid Propranolol Sulphonylureas Theophylline TCA - dothiepine Napthalene (mothball) Organophosphate Paraquat Camphor Hydrocarbon Strychnine Corrosive \+ toxic alcohols / essential oils
N-acetylcystine reigmen
200mg/kg over 4 hrs, then 100mg/kg over 16 hrs.
Iron overdose antidote
Desferrioxamine 15 mg/kg
Ethanol dosing as antidote
Loading dose 600 mg/kg and infusion of 80-150 mg/kg/hr
Naloxone dose
5-10 mcg/kg (max 400 mcg)
Infusion 10 mcg/kg/hr
Anticholinergic effects
Hyperthermia Myosin Dry flushed skin Delirium Urinary retention Tachycardia
4 phases of iron overdose
6 hrs - GI irritation, hypotension
6-12 hrs - improving
12-24 hrs - metabolic acidosis, altered mental status, pulmonary oedema, coagulopathy/death
4-6 weeks - GI strictures
Intervention level for toxicity in iron overdose
> 60mg/kg significant symptoms - AXR & lab investigations
100 mg/kg potentially lethal
Management of oral hypoglycaemic overdose
5 mls/kg glucose 10%
Octreotide - inhibit insulin secretion from pancreas, 1 mcg/kg IV bolus and infusion
