Toxicology Flashcards

Question

Lithium

Answer 1

Narrow therapeutic index 0.8-1.2 Toxicity with intercurrent illness Acute > 40mg/kg, symptoms over 3-5 days < 1.5 Lethargy, fine tremor, memory deficits < 2.5 confusion, visual disturbances, ataxia, coarse tremor, hyperactive reflexes < 3.5 myoclonic twitches, nystagmus, stupor > 3.5 seizure, flaccid paralysis, coma T wave flattening or inversion, prolonged PR/QRS/QT Hypokalaemia, abnormal TFTs Gastric lavage Diuresis with IVF Dialysis Supportive

Answer 2

Acute - n+v, diarrhoea, hyper salivation, garlic odour, haematemesis, hyperthermia. Subsequent hepatic/renal damage and encephalopathy Bone marrow suppression 2-4 weeks Painful peripheral neuropathy 1-3 weeks Chronic - hair and nails, mees lines, desquamating rash, headache, confusion, seizures 24 hour urine arsenic level, X-ray, hair/nail clippings, prolonged QT Whole bowel irrigation Chelation - BAL, DMSA, Penicillamine

Answer 3

Fumes, FB retention, contaminated drinks, improper storage foods in pewter, leaded glass, paint, batteries Myalgia, hypo chromic microcytic anaemia, painless wrist drop, encephalopathy, HTN, gout, nephritis, abdo pain, infertility Lead levels represent last 3-5 weeks Children > 0.5 act on, symptomatic > 2.9 Chelation BAL or CaEDTA

Answer 4

Inorganic - batteries, vinyl, acetaldehyde, embalming, cosmetics Ashen grey MM, metallic taste, stomatitis, abdo pain, poor muscle tone, red/oedmatous soles and palms, tachycardia, high/low BP Organic - contaminated foods, paper/wood preservatives Over days/weeks Scotoma, ataxia, parasthesia, hearing loss, dysarthria, tremor, cognitive defects, paralysis Mercury blood or urine levels Xray Decontamination Can dialyse Chelation - BAL, penicillamine

Answer 5

CaEDTA - lead, zinc Penicillamine - copper, second line lead, iron, zinc, mercury, arsenic. CI in pregnancy, renal disease, penicillin allergy BAL - acute inorganic mercury, lead CI in peanut allergy DMSA - mercury, lead

Answer 6

Large ingestions mean P450 pathway needed to metabolise which produced NAPQI - hepatic, renal, cardiac, neuro toxic Increased risk hepatoxicity: - depletion glutathione - malnutrition, HIV, chronic hepatic - induction P450 - ETOH, anticonvulsants etc Toxic doses: > 10g or > 200mg/kg Very large > 50g or > 1000mg/kg or > 3 x above nomogram Repeated: > 12g or > 300mg/kg (>150mg/kg children) over single 48 hour period OR > 4g or > 60mg/kg per 24 hour period for 48 hours with associated abdo pain/nausea/vomiting

Answer 7

Level taken at 4 hours Nomogram validated to 16 but extrapolated to 24 Check baseline ALT in all If massive or features hepatoxicity then full LFTs, coats, electrolytes (hypokalaemia common), blood gas (for metabolic acidosis), glucose (hypogylcaemia common)

Answer 8

Charcoal if within 2 hours then NAC 200mg/kg IBW over 4 hours then 100mg/kg over 16 hours - if level is > 2 x nomogram then second bag is at double dose (so 200mg/kg over 16 hrs) Check ALT 2 hours before stopping - if > 50 or rising then need to continue Check paracetamol 2 hours before stopping only if initial level was > 2 x normogram - if > 66 then need to continue If continuing then can only stop when: ALT/AST decreasing INR < 2 Patient clinically well 100% protection if started by 8 hours Adverse effects - vomiting, fever, allergy - stop infusion, give antihistamine, restart at 1/2 rate for 30 mins then increase to normal rate

Answer 9

IV paracetamol overdose Very large overdose - > 50g or > 1g/kg or > 3 x nomogram level Initial hepatotoxicity ALT > 1000 Liver unit: INR > 4.5 anytime or > 3 at 48 hours Oliguria or creat > 200 Acidosis pH < 7.3 despite treatment Persistent hypoglycaemia SBP < 80 despite resus Severe thrombocytopenia Encephalopathy Survival < 10% without transplant

Answer 10

8-24 hours Start NAC immediately Check paracetamol and ALT levels If under nomogram and ALT < 50 - no further treatment If above line or > 50 then NAC as per protocol, recheck at 2 hours prior to stopping as per acute ingestion > 24 hours Start NAC and check levels If paracetamol < 66 and ALT < 50 then stop If either elevated continue as per acute ingestion

Answer 11

Measure paracetamol and ALT Start NAC if paracetamol > 120 or ALT > 50 Repeat at 8 hours If paracetamol < 66 and ALT < 50/static can stop If elevated then continue NAC and recheck levels every 12 hours - stop when meets criteria above

Answer 12

If < 10g or 200mg/kg - paracetamol level 4 hours post ingestion (start NAC if above line) - further level 4 hours after this (start NAC if above line) - if both below, d/c If > 10g or 200mg/kg - charcoal up to 4 hours and consider more than 1 dose - start NAC and complete 20 hours regardless of initial paracetamol level - check level and ALT 2 hours before stopping, stop if meets usual criteria

Answer 13

CI - threatened airway, bowel perforation, bowel obstruction, GI haemorrhage Adverse effects - aspiration, n+v, bloating, metabolic acidosis, delay/distraction from other resus/supportive measures, labour intensive Give PO or NG 2L/hour (children 25ml/kg/hr)

Answer 14

- Cardiotoxicity due sodium channel blockade (propranolol, TCAs, chloroquine, quinine, bupropion) - Urinary alkalisation (salicylates, phenobarbital) - profound acidosis (cyanide, toxic alcohol, isoniazid) CI - APO, hypoK, severe hyperNa, renal failure Adverse effects - alkalosis (keep pH < 7.6), hyper Na, hyper osmolarity, hypoK, local tissue irritation, fluid overload 2mmol/kg bolus initially In cardiotoxicity can repeat 5 mins until stable Infusion 100mmol in 1000mls at 250ml/hr guided by ABG and ECG

Answer 15

Acute - sympathomimetic symptoms 4-6 hours Supportive, benzos, labetolol to control BP, B blockers for arrhythmia, cooling Chronic - weight loss, poor dentition, cardiomyopathy, insomnia, paranoia, psychosis, social effects Withdrawal in 85% lasting 3-5 days or up to weeks

Answer 16

Acute - sympathomimetic symptoms Myocardial ischaemia (50% thrombus, 50% vasospasm) Prolonged QRS and QTc HTN, ICH, seizures Crack lung - fever and haemoptysis Movement disorders Chronic - Cardiomyopathy, myocarditis (IV), perforated nasal septum Supportive May need ACS treatment

Answer 17

Acute - triad CNS depression, resp depression, miosis May be aspiration, hypothermia, rhabdo, compartment syndrome, hypoxic brain injury Pethidine - serotonin syndrome Dextropropxyphene - seizures Naloxone 100-400mcg, repeat as needed, infusion if 2 x given (2/3 initial dose needed to reverse/hr and titrate) Observe 4-12 hours depending on preparation Withdrawal lasts 6hrs - 2 weeks - GI symptoms, lacrimation, salivation, anxiety, mydriasis, diaphoresis. Admit if severe/complications/intercurrent illness. Give opiates or clonidine

Answer 18

Packing - concealing drugs in planned way, large amounts so can be severe toxicity if leaks, bowel obstruction Stuffing - last minute concealment, smaller package but badly wrapped Plain films useful, CT if concerns Stuffers - observe 8 hours Packers - observe until passed and repeat imaging OK

Answer 19

Colourless and odourless Cigarettes, car exhausts, heating malfunction 240 x affinity than O2 for Hb Features correlate to end level CO exposure Headache, vertigo, ataxia, visual disturbance, confusion, seizures, coma, n+v, arrhythmias, ischaemia, pulmonary oedema, cherry red skin Long term neuropsychological symtoms (increased risk if pregnant, > 55, ischaemia, acidosis, significant LoC) Ix - elevated CO level, metabolic acidosis, hyperglycaemia, rhabdo, renal injury Rx - 100% O2 at least 8 hrs/until symptoms resolved (24hrs if pregnant) Hyperbaric O2

Answer 20

Fires, photographic/tanning/plastic industries, sodium nitroprusside, pips/seeds (almonds, peaches, apples etc) Death rapid Burning MM, SOB, vomiting, tachycardia, confusion, seizures, coma, CVS collapse, bitter almond odour, cherry red macula, miosis HAGMA with elevated lactate Gastric aspirate - litmus blue/green if cyanide Cyanide levels often delayed Rx - remove clothing, do not wash, 100% O2, hyperbaric O2, supportive Hydroxycobalamin 5g Sodium thiosulphate 50mls 25% Produce methaemoglobinaemia (not if CO poisoning also present) with sodium nitrite or amyl nitrite

Answer 21

Iron in oxidised form in Hb so not able to carry O2 Drugs - sulphurs, dapsone, chloroquine, nitroglycerin, prilocaine Chemicals - nitrites, phenols, recluse spider bite Infants < 6/12 - prematurity, dehydration, systemic acidosis, congenital Symptomatic levels 20-50%, lethal > 70% Cyanosis out of proportion to resp distress SOB, tachycardia, hypotension, met acidosis, dizzy, seizures, coma Methylene blue img/kg if severe

Answer 22

Sodium channel blockade and antimuscarinic effects Peak level 8-12hrs Severe toxicity if > 160 Dizziness, confusion, ataxia, dystonic reactions, reduced GCS, seizures, tachycardia, QRS widening, long QTc, hypotension, CVS collapse Multi dose activated charcoal IV bicarb Dialysis Supportive

Answer 23

GABA effects Peak level 10 hours > 400mg/kg severe Lethargy, coma (if level > 850), tachycardia, hypotension Thrombocytopenia, leucopenia, metabolic acidosis, hypernatraemia, hypoglycaemia, high ammonia Charcoal Supportive Dialysis if severe or level > 4800

Answer 24

Alcohol intoxication Alcohol withdrawal Serotonin syndrome - SSRIs, SNRIs, TCAs, lithium, tramadol, fentanyl, MDMA Neuroleptic malignant syndrome - haloperidol, metoclopramide, prochlorperazine Sympathamomietic syndrome - amphetamine, cocaine, theophylline Anticholinergic syndrome - parkinson drugs, TCAs, antipsychotics, carbamazepine, oxybutynin Cannabis Hallucinogens Salicylate OD Theophylline OD Atypical antipsychotic OD

Answer 25

Meningoencephalitis Systemic sepsis Heat stroke Anticholinergic syndrome Serotonin syndrome Neuroleptic malignant syndrome Sympathomimetic syndrome Alcohol withdrawal Methylxanthine toxicity Salicylate toxicity Thyrotoxicosis Phaeochromocytoma Malignant hyperthermia

Answer 26

Haloperidol, chlorpromazine, prochlorperazine, metoclopramide etc 0.5-1.5% patient on neuroleptic drugs Start, change, addition of drug increases risk Young, male, dehydration, comorbid, organic brain disorder, genetic increases risk Slow onset over days, weeks to resolve CNS - confusion, stupor, coma Autonomic - fever, tachycardia, labile BP, arrhythmias Neuromuscular - lead pipe rigidity, bradykinesia, reduced reflexes, abnormal postures/movements, mutism, staring Can have high WCC, AKI, deranged LFTs, NAGMA Supportive, cooling, GTN for HTN, ETT Bromocriptine - 2.5mg PO/NG Q8hr

Answer 27

SSRIs, SNRIs, TCAs, MAOIs, lithium, amphetamines, tramadol, fentanyl Start, change, addition, OD increases risk More rapid onset over hours and resolve over 24hrs CNS - delirium, apprehension, anxiety, seizure, coma Autonomic - HTN, tachycardia, hyperthermia, sweating, mydriasis, flushing, diarrhoea Neuromuscular - clonus (sustained, ocular/ankle), hyperreflexia, increased tone, rigidity, tremor Hunter diagnostic criteria (clonus, agitation, sweating, tremor, hypertonia, hyperreflexia Supportive ETT if temp > 39.5 Hydration Cyproheptadine mild/mod 8mg PO Q8hr

Answer 28

Often other drug effects Antiparkinson, antihistamine, TCAs, antipsychotics, carbamazepine, atropine, oxybutynin, orphenadrine, datura/mushrooms Central - agitated delirium, picking, visual hallucinations, mumbling, slurred speech, fluctuating mental state, tremor, myoclonus, seizures, coma Peripheral - tachycardia, dry mouth, dry skin, mydriasis, flushing, urinary retention, reduced bowel sounds, hyperthermia (blind as a bat...) Supportive Adequate hydration, IDC Phyostigmine if not responding to benzos and isolated anticholinergic - 0.5-1mg IV

Answer 29

Acetylcholine agonists - acetylcholine, pilocarpine, nicotine, mushrooms Acetylcholinesterase inhibitors - oraganophosphates, carbamates, chemical warfare, donepezil, neostigmine CNS - agitation, seizures, coma Muscarinic (DUMBBELLS) - diarrhoea, diaphoresis, urinartion, miosis, bronchospasm, bonchorrhoea, emesis, lacrimation, lethargy, salivation Nicotinic - HTN, tachycardia, resp muscle weakness, fasiculations Killer B's - bronchospasm, bronchorrhea, bradycardia, breathing bad (resp muscle paralysis) Early ETT (resp muscle weakness, secretions, coma) Hydration (lots of secretions) Atropine 1.2g IV 2-3 mins doubling dose then infusion to stop bronchospasm/bronchorrhea and bradycardia Pralidoxime in organphosphate

Answer 30

Inhibit acetylcholinesterase Can bind irreversibly in ageing (not carbamates) Inhalation - usually within 5 mins Transdermal/oral - several hours Cholinergic signs (DUMBBELLS etc), pulmonary oedema in 40%, garlic smell Delayed muscle weakness after resolution initial cholinergic signs 24-96hrs in 10-40% (resp muscles, cranial nerves, pros limb flexors) Polyneuropathy at 2-3 weeks - rare ST elevation, QTc prolongation, arrhythmias common RBC acetylcholinesterase or plasma pseudocholinesterase - often delayed PPE - universal precautions, remove clothing, soap and water Atropine 1.2mg IV Q5mins doubling dose until chest clear, secretions, dried, HR acceptable Pralidoxime - must be given early

Answer 31

Petrol, diesel, kerosene, turps, toluene, camphor CNS - ataxia, euphoria, seizures, coma, myopathy, cerebellar dysfunction, encephalopathy CVS - in severe - arrhythmias, hypotension GIT - d+v, haematemesis Pulmonary - aspiration, oedema Bone marrow suppression Metabolic acidosis Supportive, dialysis

Answer 32

Most lethal poison, small sip can kill Early - GI /corrosive injury Multiorgan failure around 48 hours If survive > 48 hours get pulmonary fibrosis Serum level >5 fatal, >2.5 90% fatal Extensive bloods to assess organ damage PPE Immediate decontamination, remove clothes, fullers earth/charcoal Dialysis O2 only is sats < 90 and aim no more than 92% Consider palliation

Answer 33

Onset 4 hours, offset 12 hours Es/citalopram worse - more associated with seizure (2-10%, short), dose dependent QTc prolongation when >500mg - rarely tornadoes Risk - >500mg citalopram, >1200mg fluoxetine Tremor, anxiety, mydriasis, nausea, drowsy, tachycardia Serotonin syndrome if coningestants, severe Supportive Early ETT if temp >39.5 Adequate hydration Cyproheptadine 8mg PO TDS if mild/mod

Answer 34

Delayed 6-12 hours, 16 hours observation Anxiety, sweating, mydriasis, tachycardia, HTN, features serotonin toxicity Seizure risk dose dependent >4.5g close to 100% CVS effects if >8g - hypotension, QRS prolongation, QTc prolongation Supportive Bicarb if prolonged QRS

Answer 35

Effects at NA, serotonin, GABA, alpha, histamine and sodium channels >10mg/kg severe Rapid onset 1-2 hours CNS - agitation, confusion, twitching, jerking, bladder/bowel paralysis, seizures, coma Anticholinergic - mydriasis, myoclonic jerks, tachycardia CVS - hypotension, prolonged PR/QRS/QTc, terminal R wave in aVR QRS >100-20 predictive seizures, >160 predictive VT Anticipate hypotension - fluids Bicarb in refractory hypotension fixes 90% Bicarb for prolonged QRS Lignocaine next line Early ETT

Answer 36

>2mg/kg serious toxicity Can be delayed up to 24 hours Serotonin and sympathomimetic symptoms esp if coningestants Tyramine reaction if eat certain foods - occipital headache, HTN crisis, agitation, sweating Supportive HTN - GTN or labetolol

Answer 37

ABC, seizures, glucose, temp Risk assessment - drug, dose, time, current clinical status (does picture fit), patient factors (comorbidities, weight) Supportive care (fast hugs in bed please - fluids, analgesia/antiemetics, sedation, thromboprophylaxis, head up, ulcer prophylaxis, glucose control, skin/eye care, IDC, NGT, bowel care, environment, de-escalation, psychosocial support) Investigations (ECG, paracetamol, others) Decontamination - charcoal, while bowel, endoscopy Enhanced elimination - multi dose activated charcoal, urinary alkalinisation, dialysis Antidotes Disposition

Toxicology Flashcards

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