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Overdose & Poisoning — Toxicology Nursing

GCC Nursing Exam Prep • DHA • DOH • SCFHS • QCHP • MOH

Toxicology Approach — Primary Survey & Decontamination

PRIORITY: Airway > Breathing > Circulation before ANY specific antidote. Identify the toxidrome pattern before acting on specific drug assumptions.

ABCDE Primary Survey in Poisoning

  • Airway: Position, suction, jaw thrust; intubate if GCS ≤8 or airway compromise
  • Breathing: SpO2, RR, auscultate; assisted ventilation if hypoventilating
  • Circulation: BP, HR, rhythm; IV access x2; 12-lead ECG
  • Disability: GCS, pupils (size, reactivity, symmetry), BM (glucose)
  • Exposure: Remove all clothing, look for patches/needle marks/chemical burns

SAMPLE History — Poisoning Adaptation

  • Substance — exact name, formulation, concentration
  • Amount — number of tablets/mL; body weight for dose/kg
  • Method — ingestion / inhalation / dermal / injection
  • Purpose — intentional (self-harm, assault) vs accidental
  • Last seen well — time of ingestion matters for decontamination window
  • Events since — vomiting, seizures, loss of consciousness, interventions

ECG in Toxicology — Key Patterns

QRS Widening (>120ms)

  • Tricyclic antidepressants (TCAs)
  • Flecainide / Class Ic antiarrhythmics
  • Cocaine (sodium channel blockade)
  • Chloroquine / hydroxychloroquine
  • Diphenhydramine (antihistamine)
QRS >100ms → sodium bicarbonate

QTc Prolongation (>500ms)

  • Antipsychotics (haloperidol, quetiapine)
  • Methadone, sotalol, amiodarone
  • Fluoroquinolone antibiotics
  • Risk: torsades de pointes → IV magnesium 2g

Bradycardia

  • Beta-blockers, digoxin, opioids
  • Calcium channel blockers, clonidine

Tachycardia

  • Stimulants (cocaine, amphetamines, MDMA)
  • Anticholinergics, theophylline, salicylates

Decontamination Principles

Skin & Eye Exposure

  • Remove contaminated clothing (protect staff — gloves, apron)
  • Copious water irrigation — skin 15 min, eyes 20 min
  • Morgan lens for prolonged eye decontamination

Activated Charcoal (AC)

  • Dose: 1 g/kg orally (max 50g adult)
  • Window: Within 1 hour of ingestion
  • Requirement: Protected airway (no vomiting, no reduced consciousness)
  • Contraindications: Hydrocarbon, caustic, metals, alcohols

Gastric Lavage

  • Rarely used; consider within 1h for massive life-threatening ingestion
  • Requires protected airway; risk aspiration & oesophageal injury

Enhanced Elimination — STUMPED

Haemodialysis (HD) effective for these drugs:

  • Salicylates (aspirin) — severe toxicity
  • Theophylline
  • Uremia-associated toxins
  • Methanol
  • Phenobarbital / phenytoin (haemoperfusion)
  • Ethylene glycol (antifreeze)
  • Digoxin (Fab preferred), lithium
Urinary alkalinisation (sodium bicarbonate IV to urine pH 7.5–8.5) enhances elimination of weak acids: salicylates, methotrexate, chlorpropamide

Multiple-Dose AC (MDAC)

For: theophylline, carbamazepine, quinine, dapsone — AC 50g q4h

ECG Changes in Toxicology — Quick Reference Table ▶
ECG FindingToxin / DrugMechanismManagement
QRS >100msTCA, cocaine, flecainide, chloroquineNa+ channel blockadeSodium bicarb 1–2 mmol/kg IV bolus
QTc >500msAntipsychotics, methadone, sotalolK+ channel blockadeIV Mg 2g; correct K+; avoid QT drugs
Sinus bradycardiaBeta-blockers, Ca2+ channel blockersChronotropy ↓Atropine; glucagon; HDIE
AV block (various degrees)Digoxin, beta-blockers, CCBs, TCANodal conduction ↓Specific antidote; pacing if complete
Torsades de pointesSotalol, antipsychotics, macrolidesQTc ↑ + pauseIV Mg 2g, isoproterenol, overdrive pacing
Bidirectional VTDigoxin toxicityTriggered activityDigiFab (Digoxin-specific Fab)
Sinus tachycardiaCocaine, amphetamines, anticholinergicsSympathomimetic/anticholinergicBenzodiazepines; phentolamine (cocaine)
Epsilon wave / Brugada patternCocaine, TCAs, propofol infusion syndromeNa+ channel, RV conductionSodium bicarb; remove offending agent

Common Toxidromes — Pattern Recognition

A toxidrome is a cluster of signs and symptoms caused by a class of drugs. Recognising the pattern guides immediate management even before the specific drug is confirmed.

Interactive Toxidrome Identifier & Antidote Guide

Select all symptoms present, then click Identify Toxidrome.

Vitals

Pupils

Neurological

Other Signs

Opioid Toxidrome

Miosis↓ConsciousnessResp DepressionBradycardia

Classic triad: CNS depression + miosis + respiratory depression. Caused by heroin, morphine, codeine, oxycodone, fentanyl, tramadol, methadone.

Naloxone (Narcan): 0.4–2mg IV/IM/intranasal — repeat every 2–3 min. Max cumulative dose 10mg. Infusion: 2/3 of effective bolus dose per hour. Short half-life — monitor for re-narcotisation especially with methadone/long-acting opioids.

Monitoring: SpO2, RR, GCS q15min; consider 4–6h observation minimum

Anticholinergic Toxidrome

MydriasisTachycardiaDry SkinFeverUrinary Retention

"Mad as a hatter, dry as a bone, red as a beet, blind as a bat, hot as a hare, full as a flask"

Caused by: antihistamines (diphenhydramine), TCAs, atropine, scopolamine, antipsychotics, belladonna plants.

Physostigmine: 1–2mg slow IV (over 5 min) for severe delirium/seizures. Caution: not for TCA OD (may cause asystole). Symptomatic: cool environment, BZDs for agitation.

Cholinergic / Organophosphate Toxidrome

SLUDGE/DUMBELSMiosisBradycardiaBronchospasm

SLUDGE: Salivation, Lacrimation, Urination, Defecation/Diarrhoea, GI cramps, Emesis

DUMBELS: Defecation/Diarrhoea, Urination, Miosis, Bradycardia/Bronchospasm, Emesis, Lacrimation, Salivation

Causes: organophosphate pesticides, nerve agents (sarin, VX), carbamates

Atropine: 2–4mg IV every 5–10 min — titrated to dry secretions (not heart rate). May need 20–100mg in severe poisoning.
Pralidoxime (2-PAM): 1–2g IV over 15–30 min; effective only within 24–48h before "ageing".
Protect responders — decontaminate before resuscitation. PPE essential.

Sympathomimetic Toxidrome

TachycardiaHypertensionMydriasisHyperthermiaAgitation

Causes: cocaine, amphetamines, MDMA (ecstasy), methamphetamine, bath salts, pseudoephedrine

  • Hypertension + agitation: Benzodiazepines first-line (lorazepam/diazepam)
  • Hyperthermia: Cooling blankets, ice packs, IV fluids — target <38.5°C
  • Seizures: BZDs; avoid phenytoin
AVOID beta-blockers in cocaine toxicity — causes unopposed alpha vasoconstriction, worsens hypertension and coronary spasm

Phentolamine (alpha-blocker) for severe cocaine-induced hypertension: 2.5–5mg IV

Serotonin Syndrome

ClonusTremorAgitationHyperthermiaDiaphoresisTachycardia

Hunter Criteria (one required):

  • Spontaneous clonus
  • Inducible clonus + agitation or diaphoresis
  • Ocular clonus + agitation or diaphoresis
  • Tremor + hyperreflexia
  • Hypertonia + temp >38°C + ocular or inducible clonus

Causes: SSRIs/SNRIs, MAOIs, tramadol, linezolid, triptans, fentanyl, St John's Wort combinations

Management:

Cyproheptadine: 12mg orally/NG loading dose, then 2mg every 2h (max 32mg/day) — 5-HT2A antagonist
  • Stop all serotonergic agents immediately
  • BZDs for agitation and muscle rigidity
  • Active cooling for temp >39°C
  • Dantrolene for severe hyperthermia/rigidity
  • Avoid physical restraint — worsens hyperthermia
  • ICU monitoring for severe cases
Serotonin syndrome vs Neuroleptic Malignant Syndrome (NMS): Serotonin — rapid onset hours, clonus, hyperreflexia, diaphoresis. NMS — slow onset days-weeks, lead-pipe rigidity, antipsychotic drug context, treat with bromocriptine/dantrolene.

Sedative-Hypnotic Toxidrome

↓ConsciousnessAtaxiaSlurred SpeechNormal Pupils

Causes: benzodiazepines, alcohol, barbiturates, GHB, z-drugs (zopiclone, zolpidem), carisoprodol

Key difference from opioid: pupils usually normal size (not pinpoint); respiratory depression less marked (except barbiturates)

Flumazenil: 0.2mg IV over 30s, repeat 0.1mg q60s to max 1mg — BZD reversal. Use with extreme caution in BZD-dependent patients (precipitates withdrawal seizures). Do NOT use if TCA co-ingestion suspected.

Specific Antidotes — Recognition & Dosing

Poison / DrugAntidoteDose / RouteKey Notes
Paracetamol (acetaminophen)N-Acetylcysteine (NAC)See protocol belowRumack-Matthew nomogram; King's College criteria
OpioidsNaloxone0.4–2mg IV/IM/IN q2–3minShort-acting; infusion for long-acting opioids
BenzodiazepinesFlumazenil0.2mg IV → 0.1mg q60s; max 1mgCaution in BZD-dependent; avoid if TCA co-ingestion
OrganophosphatesAtropine + PralidoximeAtropine 2–4mg IV; 2-PAM 1–2g IVTitrate atropine to dry secretions, not HR
Beta-blockersGlucagon + HDIEGlucagon 3–5mg IV bolus; Insulin 1u/kg/hHigh-dose insulin euglycaemia (HDIE); 10% glucose co-infusion
Calcium channel blockersIV Calcium + HDIE + Lipid emulsionCaCl2 1g IV q10–20min; Insulin 1u/kg/hIntralipid 1.5ml/kg bolus for lipid-soluble CCBs
DigoxinDigoxin-specific Fab (DigiFab)Based on ingested dose or serum levelBidirectional VT, K+ >5.5 = urgent Fab
Tricyclic antidepressantsSodium bicarbonate1–2 mmol/kg IV bolusQRS >100ms; target pH 7.45–7.55
Methanol / Ethylene glycolFomepizole (4-MP) or EthanolFomepizole 15mg/kg IV loadADH inhibitor; +HD if severe acidosis
CyanideHydroxocobalamin (Cyanokit)5g IV over 15 min (adult)Smoke inhalation / industrial exposure
Carbon monoxide100% O2 / Hyperbaric O2100% NRB mask; HBO if criteria metHBO: COHb >25%, neuro sx, pregnancy, cardiac
Warfarin / VKAVitamin K1 + FFP / PCCPhytomenadione 5–10mg slow IV/POPCC for urgent reversal; FFP if PCC unavailable
Heparin (UFH)Protamine sulphate1mg per 100u heparin given (max 50mg)Slow IV over 10 min; monitor for anaphylaxis
IronDesferrioxamine15mg/kg/h IV (max 80mg/kg/day)Urine turns "vin rosé" colour if effective
MethotrexateLeucovorin (folinic acid)Dose/timing based on MTX levelsGlucarpidase (carboxypeptidase G2) for severe OD
LithiumHaemodialysisTarget post-HD level <1 mmol/LNo specific antidote; HD for levels >3.5 or symptomatic
Salicylates (aspirin)Urinary alkalinisation + HDNaHCO3 IV; target urine pH 7.5–8.5HD if level >700mg/L or severe toxicity
Snake bite (haemotoxic)AntivenomSpecies/region specificSaudi/UAE/Oman specific protocols
Scorpion envenomationAntivenom + prazosinRegional antivenom IVHigh incidence Saudi Arabia; prazosin for systemic effects
Paracetamol Overdose — NAC Protocol & King's College Criteria ▶

21-Hour IV NAC Protocol (Prescott)

Bag 1: 150mg/kg NAC in 200mL 5% glucose over 1 hour
Bag 2: 50mg/kg in 500mL 5% glucose over 4 hours
Bag 3: 100mg/kg in 1000mL 5% glucose over 16 hours

When to Treat

  • Paracetamol level above treatment line on Rumack-Matthew nomogram (plotted at time post-ingestion)
  • Unknown time of ingestion with any detectable level
  • Staggered overdose — treat empirically
  • Start within 8–10h for maximum hepatoprotection; still beneficial up to 24h+

NAC Adverse Reactions

  • Anaphylactoid reaction in ~15% (flushing, wheeze, urticaria)
  • Manage: slow/stop infusion, antihistamine, restart at slower rate
  • True anaphylaxis rare; do NOT withhold if genuine OD

King's College Criteria — Liver Transplant

Paracetamol-induced ALF (non-paracetamol in brackets):

Arterial pH <7.30 (after resuscitation)
OR all three:
• PT >100s (INR >6.5)
• Creatinine >300 µmol/L
• Grade III–IV hepatic encephalopathy

Indicators of Severe Hepatotoxicity

  • ALT/AST >1000 IU/L by 24–36h post-ingestion
  • INR rising >2 at 24h or >3.5 at 48h
  • Hypoglycaemia — sign of hepatic failure
  • Metabolic acidosis with raised lactate

Monitoring During NAC

  • Paracetamol level, INR, LFTs, U&E, creatinine at 0, 12, 24h
  • Blood glucose 4-hourly (hypoglycaemia risk)
  • Consider extended NAC course if INR still rising
Organophosphate / Nerve Agent — Atropine Titration Guide ▶

Atropine Titration Protocol

Endpoint of atropinisation: DRY secretions — NOT heart rate or pupil size
Initial dose: 2–4mg IV (paediatric 0.02mg/kg)
Double dose every 5 min if secretions persist: 4mg → 8mg → 16mg → 32mg
Maintenance: infusion 10–20% of total loading dose per hour
Severe/mass casualty: may require 20–100mg+ in first hour

Signs of Adequate Atropinisation

  • Dry mouth and skin
  • Clear chest — no wheeze or crackles
  • Reduced bronchorrhoea / secretions
  • HR 80–100 bpm (secondary effect)
  • Skin flushed, warm, dry

Signs of Over-Atropinisation

  • Tachycardia >120 bpm
  • Agitation, confusion, pyrexia
  • Urinary retention, ileus
  • → Reduce infusion rate; do NOT stop abruptly

Pralidoxime (2-PAM) Use

Loading: 1–2g IV (30mg/kg child) over 15–30 min
Maintenance: 500mg/h infusion
Time window: Must be given within 24–48h before acetylcholinesterase "ageing"

Intermediate Syndrome

  • Occurs 24–96h after apparent recovery
  • Proximal limb weakness, neck flexion weakness
  • Respiratory muscle paralysis — can be fatal
  • Requires ventilatory support

OP Severity Grading

GradeFeaturesManagement
MildMiosis, hypersalivation, anxietyDecontamination, oral atropine
ModerateSLUDGE signs, bronchospasmIV atropine, 2-PAM, supportive
SevereSeizures, resp failure, comaIntubation, high-dose atropine, ICU
Decontamination first! Remove clothing and irrigate skin before treatment to protect healthcare workers

Beta-Blocker Overdose

  • Glucagon: 3–5mg IV bolus (paediatric 50–150 mcg/kg); follow with 1–5mg/h infusion — bypasses beta receptor
  • HDIE (High-Dose Insulin Euglycaemia): Insulin 1 unit/kg/h IV + 10% glucose infusion; monitor BGL q15–30 min; target glucose 5–10 mmol/L
  • Atropine: 0.5–1mg IV for symptomatic bradycardia (limited effect)
  • Calcium chloride: 1g IV q10–20min (up to 3 doses)
  • Lipid emulsion: For lipophilic beta-blockers (propranolol, metoprolol) — Intralipid 20% 1.5ml/kg bolus
  • Transvenous pacing for refractory bradycardia
  • ECMO as rescue therapy

Calcium Channel Blocker Overdose

  • IV Calcium: CaCl2 1g IV (or calcium gluconate 3g) q10–20min up to 3 doses; infusion 0.2–0.4ml/kg/h CaCl2
  • HDIE: Insulin 1 unit/kg/h + 10% glucose (same as beta-blocker)
  • Glucagon: 3–5mg IV (less effective than for beta-blockers)
  • Lipid emulsion (Intralipid): 1.5ml/kg IV bolus over 1 min; repeat x2 if no response; infusion 0.25ml/kg/min x60min — especially for verapamil/diltiazem
  • Methylene blue 1–2mg/kg for vasodilatory shock
  • ECMO consideration for refractory shock

Drug-Specific Emergencies

HIGH-RISK PRESENTATIONS: TCA overdose, cyanide poisoning, and carbon monoxide are immediately life-threatening — recognise and treat within minutes.

Tricyclic Antidepressant (TCA) Overdose

Drugs: amitriptyline, imipramine, clomipramine, nortriptyline, doxepin

Toxicity Mechanism & Features

  • Sodium channel blockade → QRS widening
  • Alpha-1 blockade → hypotension
  • Muscarinic blockade → anticholinergic signs
  • GABA-A antagonism → seizures
  • H1/H2 blockade → sedation
QRS >100ms = high risk seizures & arrhythmias; QRS >160ms = very high risk VF/VT

Key Signs

  • Dry mouth, tachycardia, mydriasis (anticholinergic)
  • QRS widening on ECG
  • Hypotension (often early & severe)
  • Seizures → status epilepticus
  • Ventricular arrhythmia

Management

Sodium Bicarbonate: 1–2 mmol/kg IV bolus (50–100mL 8.4% NaHCO3). Repeat until QRS <100ms or pH 7.50–7.55. Dual mechanism: alkalinisation dissociates drug from Na+ channel; sodium loading increases gradient.

Seizures

  • BZDs first line: Diazepam 5–10mg IV or lorazepam 2–4mg IV
  • DO NOT use phenytoin — also blocks Na+ channels, worsens QRS
  • Propofol for refractory seizures + intubation

Hypotension

  • Noradrenaline — vasopressor of choice
  • AVOID dopamine — indirect acting; catecholamines depleted
  • IV fluids bolus 250–500mL NaCl 0.9%
Physostigmine CONTRAINDICATED in TCA OD — may precipitate asystole/seizures

Cyanide Poisoning

Sources: smoke inhalation (burning plastics/wool), industrial (electroplating, mining), hydrogen cyanide gas, apricot kernels (amygdalin)

Clinical Features

  • Rapid loss of consciousness
  • Metabolic acidosis + high lactate (>10 mmol/L)
  • SpO2 normal despite severe toxicity (cells can't use O2)
  • Cherry-red skin (may be absent)
  • Cardiovascular collapse
Hydroxocobalamin (Cyanokit): 5g IV over 15 minutes (adult). Paediatric: 70mg/kg. Repeat dose if no response. Turns urine/skin red-brown — warn staff.

Alternative: Sodium thiosulphate 12.5g IV over 10 min (donates sulphur for rhodanese pathway)

DO NOT give amyl nitrite + sodium nitrite if CO poisoning co-suspected (worsens methaemoglobinaemia)

Carbon Monoxide Poisoning

Sources: car exhaust, faulty boilers, house fires, water heaters (common GCC indoor risk)

COHb Levels & Symptoms

COHb %Symptoms
10–20%Headache, nausea, dizziness
20–40%Confusion, syncope, chest pain
40–60%Seizures, loss of consciousness
>60%Death
100% O2 via tight-fitting NRB mask until COHb <5% (reduces CO half-life from ~5h to ~60–90min)

Hyperbaric O2 Criteria

  • COHb >25%
  • Neurological symptoms (confusion, syncope, seizure)
  • Pregnancy (any COHb >15%)
  • Cardiac involvement (troponin rise, arrhythmia)
  • Age >36 years (some guidelines)

GCC context: Nearest HBO centres: SEHA facilities Abu Dhabi, KKUH Riyadh

Methotrexate Overdose

Causes: accidental weekly vs daily dosing error; high-dose cancer therapy; intentional

Toxicity Features

  • Mucositis, oral ulceration
  • Myelosuppression (nadir 5–14 days)
  • Nephrotoxicity (MTX precipitates in renal tubules at acidic pH)
  • Hepatotoxicity
  • Neurotoxicity (leukoencephalopathy)
Leucovorin (folinic acid) rescue: 15mg IV/IM q6h; dose based on MTX level and timing. Start within 24–42h of MTX administration. Continue until MTX <0.05 µmol/L.
Glucarpidase (carboxypeptidase G2): 50 units/kg IV — for severe OD (MTX >10 µmol/L at 24–48h). Enzymatic cleavage of MTX.

Also: IV hydration + urinary alkalinisation; reduce leucovorin efficacy if given simultaneously with glucarpidase (48h gap).

Metformin-Associated Lactic Acidosis (MALA)

Risk factors: renal failure, liver failure, heart failure, alcohol, contrast media

Features

  • Severe metabolic acidosis (pH <7.2, lactate >5 mmol/L)
  • Hypotension, hypothermia
  • GI symptoms (nausea, vomiting, abdominal pain)

Management

  • Stop metformin immediately
  • IV sodium bicarbonate for severe acidosis (controversial — short-term bridge)
  • CRRT (Continuous Renal Replacement Therapy) for severe MALA — removes metformin + corrects acidosis
  • Haemodialysis if available (more efficient)
  • Supportive: fluids, vasopressors, treat precipitant
Mortality risk high if: pH <7.0 or lactate >20 mmol/L without CRRT/HD

Psychiatric & Substance Overdose

Benzodiazepine Overdose

Features: CNS depression, slurred speech, ataxia, normal pupils, mild respiratory depression (rarely fatal alone)

Flumazenil (Anexate): 0.2mg IV over 30s; repeat 0.1mg every 60s to max 1mg total. Half-life only 1 hour — watch for re-sedation especially with long-acting BZDs (diazepam, clonazepam).
CAUTION — Flumazenil contraindications:
• BZD-dependent patients (chronic use) — precipitates acute withdrawal seizures
• TCA or other pro-convulsant co-ingestion
• Raised intracranial pressure
• Epilepsy patients on BZD maintenance

In most cases: supportive care + airway management is safer than flumazenil. Reserve for intubation avoidance in low-risk patients.

SSRI/SNRI & Serotonin Syndrome Management

Drugs: fluoxetine, sertraline, escitalopram, paroxetine, venlafaxine, duloxetine

Mild to Moderate

  • Discontinue all serotonergic agents
  • Supportive care, calm environment
  • Oral cyproheptadine 12mg loading, 2mg/2h max 32mg/day
  • Lorazepam 1–2mg IV for agitation and muscle rigidity

Severe (temp >41°C, rigidity)

  • Immediate sedation + intubation
  • Active cooling (cooling blankets, ice packs, cool IV fluids)
  • Dantrolene sodium 2.5mg/kg IV for severe hyperthermia/rigidity
  • Avoid physical restraint — worsens hyperthermia and rhabdomyolysis
  • Monitor: CK, troponin, LFTs, renal function, coagulation
  • ICU admission mandatory
SSRI overdose alone rarely fatal. Most danger = serotonin syndrome from drug combinations (SSRI + tramadol, linezolid, triptans, MAOI).

Alcohol (Ethanol) Poisoning

Features by Blood Alcohol Level (BAL)

BAL (mg/dL)Clinical Features
20–100Disinhibition, euphoria, ataxia
100–250Slurred speech, diplopia, amnesia
250–400Stupor, vomiting, hypothermia
>400Coma, respiratory depression, death

Complications

  • Hypoglycaemia (especially paediatric)
  • Aspiration pneumonia
  • Hyponatraemia, hypokalaemia, hypomagnesaemia
  • Hypothermia
  • Wernicke's encephalopathy (thiamine-deficient patient)

Management

THIAMINE BEFORE GLUCOSE
Thiamine 100mg IV (or IM) BEFORE any dextrose administration
Prevents precipitation of Wernicke's encephalopathy
  • IV access + BGL monitoring
  • Position: lateral/recovery position to prevent aspiration
  • IV 0.9% NaCl if dehydrated
  • Correct electrolytes (Mg2+, K+, PO4-)
  • DO NOT induce emesis — aspiration risk
  • NO specific antidote for ethanol
  • Alcohol withdrawal: CIWA score; chlordiazepoxide/diazepam protocol
GCC context: Alcohol consumption exists despite legal restrictions; presentations may be delayed due to social stigma. Non-beverage sources: mouthwash, cleaning products, khamr (home brew).

Recreational Drug Toxicity — GCC Context

Captagon (fenethylline)

Widely encountered in Middle East/GCC. Amphetamine derivative.

  • Sympathomimetic toxidrome
  • Severe hypertension, tachycardia
  • Hyperthermia, agitation, psychosis
  • Benzodiazepines + cooling

Cannabis / Synthetic Cannabinoids

"Spice" common in GCC youth populations

  • More severe than natural cannabis
  • Severe agitation, psychosis, seizures
  • Hyperthermia, rhabdomyolysis
  • Supportive; BZDs for agitation

Tramadol Misuse

Widely available, commonly misused in GCC/Middle East region

  • Dual: opioid + serotonin effects
  • Lowers seizure threshold
  • Naloxone for opioid effects
  • BZDs for seizures

Paediatric Medication Errors & Overdose

Common Paediatric Poisonings in GCC

  • Paracetamol syrup (10-fold dosing errors)
  • Iron supplements (household tablets)
  • Antiepileptics (carbamazepine, valproate)
  • Cardiovascular drugs (digoxin, calcium channel blockers)
  • Household cleaning products
  • Button battery ingestion (emergency — alkali liquefaction)

Weight-Based Antidote Dosing Principles

Naloxone: 0.01mg/kg IV/IM/IN (neonates); titrate up
Activated Charcoal: 1g/kg (max 50g)
NAC (paracetamol): Same 21h protocol, weight-based volumes
Atropine (OP): 0.02mg/kg IV (minimum 0.1mg)
Flumazenil: 0.01mg/kg IV; max 0.2mg per dose
Dextrose 10%: 5ml/kg IV for hypoglycaemia

Prevention & Reporting

  • Report to UAE/Saudi poison centre for data collection
  • Child-resistant packaging education to families
  • Safe storage counselling on discharge

GCC Context — Regulatory, Regional & Exam Preparation

GCC Poison Centres — Emergency Contacts

Country / CentreNumberNotes
UAE — National Poisons Centre (Abu Dhabi)+971 800 424 2424/7; DHA/DOH jurisdiction
Saudi Arabia — National Poison Control Centre (Riyadh)+966 11 442 1222King Saud University Medical City
Kuwait Poison Control+965 2224 2900Ministry of Health
Qatar NCCCR / Hamad Medical+974 4439 4444QCHP regulated
Bahrain Poison Centre+973 1720 0902Salmaniya Medical Complex
Oman SQUH+968 2414 1111Sultan Qaboos University Hospital

DHA/DOH/SCFHS Toxicology Nursing Competencies

  • Recognise and classify toxidromes using systematic assessment
  • Perform rapid airway assessment and initiate resuscitation
  • Administer antidotes safely: naloxone, NAC, atropine, sodium bicarbonate
  • Perform decontamination procedures safely
  • Interpret ECG changes in poisoning (QRS/QTc)
  • Document and report poisoning incidents per DHA/MOH regulations
  • Escalate to clinical toxicologist or poison centre appropriately
  • Communicate sensitively in self-harm/intentional overdose presentations
  • Maintain chain of custody for forensic specimens
  • Apply JCIA/CBAHI patient safety standards in toxicology care

GCC-Specific Toxicological Presentations

Scorpion Envenomation (High Incidence — Saudi Arabia, UAE, Oman)

  • Androctonus and Leiurus species — most dangerous
  • Features: local pain, sweating, agitation, tachycardia, hypertension, pulmonary oedema, cardiac failure in children
  • Treatment: Polyvalent scorpion antivenom IV (early administration); prazosin 30mcg/kg for systemic effects; analgesics; ICU for severe cases
  • Paediatric cases highest risk — rapid cardiorespiratory failure

Snake Bites (UAE, Oman, Saudi Arabia)

  • Viperidae (carpet vipers, horned vipers) — haemotoxic
  • Elapidae (spitting cobras, kraits in UAE) — neurotoxic
  • Features: local envenomation, coagulopathy, neuromuscular paralysis
  • Treatment: specific antivenom; supportive; FFP for coagulopathy; avoid tourniquet
  • Regional antivenom availability varies — contact poison centre

Organophosphate Poisoning — Agricultural Expat Workers

  • High incidence in farm workers (India, Bangladesh, Pakistan expatriates)
  • Oman, UAE, Saudi farm regions
  • Skin exposure during pesticide spraying without PPE
  • Language barriers delay presentation
  • Decontamination critical — protect ED staff

Khat (Qat) — Yemen Border Areas

  • Catha edulis leaves — stimulant (cathinone = natural amphetamine)
  • Features: agitation, hypertension, tachycardia, insomnia, psychosis
  • Treatment: supportive; BZDs for agitation; antihypertensives if needed
  • Legal status varies in GCC: illegal in Saudi/UAE/Qatar; used in Yemen/Djibouti

Traditional Herbal Remedy Toxicity

RemedyToxic ComponentEffects
Hawajij (spice mix)Various herbs, piperineGI upset, drug interactions
Za'atar (thyme preparations)Thymol, carvacrolHepatotoxicity in large doses
Senna (leaves/pods)Sennoside glycosidesSevere diarrhoea, hypokalaemia, electrolyte disturbance
Black seed (Nigella sativa)ThymoquinoneGenerally safe; excess: hepatotoxicity
Al-Harjal (Zygophyllum)AlkaloidsCNS depression, cardiac effects

Pesticide Poisoning

  • Organophosphates most common class
  • Carbamates (shorter duration, no ageing of AChE)
  • Paraquat (irreversible pulmonary fibrosis — no antidote, do NOT give O2 high conc.)

GCC Nursing Exam Prep — MCQ Practice

DHA / MOH / SCFHS / QCHP style questions. Click "Show Answer" after attempting each question.

1. A 28-year-old male presents with pinpoint pupils, respiratory rate of 6/min, GCS 8, and SpO2 88%. Which is the MOST appropriate immediate intervention?

A) Activate charcoal 50g orally
B) Naloxone 0.4–2mg IV/IM and airway support
C) Flumazenil 0.2mg IV
D) Sodium bicarbonate 100mL 8.4% IV
Answer: B — Classic opioid toxidrome (miosis + CNS depression + respiratory depression). Naloxone is the specific antidote with immediate priority. Airway support simultaneously. Activated charcoal is contraindicated with reduced consciousness. Flumazenil is for benzodiazepine reversal. Sodium bicarbonate is for TCA/QRS widening.

2. A patient with organophosphate poisoning receives atropine 4mg IV. The nurse should reassess effectiveness by checking for which finding?

A) Heart rate decreased to less than 60 bpm
B) Pupils becoming dilated
C) Secretions becoming dry and chest clear
D) Blood pressure normalising above 120/80
Answer: C — The endpoint of atropinisation in organophosphate poisoning is DRY SECRETIONS (dry mouth, clear chest, no bronchospasm/bronchorrhoea). Heart rate and blood pressure are secondary endpoints. Pupil dilation is not the target. Insufficient atropine is a common error — underdosing leads to respiratory failure from secretions.

3. A 35-year-old woman took a paracetamol overdose 6 hours ago. Her serum paracetamol level is above the treatment line on the Rumack-Matthew nomogram. Which is the CORRECT first bag of the IV N-acetylcysteine (NAC) protocol?

A) 50mg/kg in 500mL 5% glucose over 4 hours
B) 100mg/kg in 1000mL 5% glucose over 16 hours
C) 150mg/kg in 200mL 5% glucose over 1 hour
D) 200mg/kg in 100mL 0.9% NaCl over 30 minutes
Answer: C — The 21-hour IV NAC Prescott protocol: Bag 1 = 150mg/kg in 200mL 5% glucose over 1 hour (loading dose); Bag 2 = 50mg/kg in 500mL over 4 hours; Bag 3 = 100mg/kg in 1000mL over 16 hours. Use 5% glucose as diluent (not saline for standard protocol). Correct order and rate are frequently tested.

4. A patient with known tricyclic antidepressant overdose develops generalised seizures. The nurse should anticipate which anticonvulsant will be ordered FIRST?

A) Phenytoin 15mg/kg IV
B) Diazepam 10mg IV
C) Physostigmine 2mg IV
D) Levetiracetam 1000mg IV
Answer: B — Benzodiazepines (diazepam, lorazepam) are first-line for seizures in TCA overdose. Phenytoin (A) is CONTRAINDICATED in TCA OD — it also blocks sodium channels, worsens QRS prolongation and cardiac toxicity. Physostigmine (C) is also contraindicated in TCA OD as it can cause asystole. Levetiracetam has limited evidence in acute TCA poisoning.

5. A nurse in a GCC emergency department is caring for a patient with suspected serotonin syndrome following combined tramadol and sertraline use. Which clinical finding is MOST characteristic of serotonin syndrome compared to anticholinergic toxidrome?

A) Urinary retention and dry mouth
B) Mydriasis and tachycardia
C) Clonus and diaphoresis
D) Flushed dry skin and confusion
Answer: C — Clonus (spontaneous or inducible) is the hallmark finding of serotonin syndrome and distinguishes it from anticholinergic toxidrome. Diaphoresis (sweating/wet skin) is also characteristic of serotonin syndrome — anticholinergic causes DRY skin. Mydriasis and tachycardia (B) occur in both. Urinary retention and dry skin (A, D) are anticholinergic features. Hunter criteria requires clonus for diagnosis.

Quick Revision — High-Yield GCC Exam Facts

  • Naloxone dose: 0.4–2mg IV, repeat q2–3min
  • NAC bag 1: 150mg/kg over 1 hour
  • Atropine endpoint in OP: dry secretions
  • TCA seizures: benzodiazepines NOT phenytoin
  • TCA hypotension: noradrenaline NOT dopamine
  • QRS >100ms: sodium bicarbonate
  • Thiamine: before glucose in alcohol-related coma
  • Flumazenil caution: BZD-dependent patients
  • Cyanide antidote: Hydroxocobalamin (Cyanokit) 5g IV
  • Carbon monoxide HBO: COHb >25%, neuro symptoms, pregnancy
  • Digoxin antidote: DigiFab (Digoxin-specific Fab)
  • Organophosphate: Atropine + Pralidoxime (within 24–48h)
  • UAE Poison Centre: 800 424 24
  • Serotonin syndrome: clonus + cyproheptadine
  • STUMPED mnemonic: drugs dialysable by HD
  • Beta-blocker OD: Glucagon + HDIE