Treating Poison and Overdose: Specifics

For BNS 1st YearDr. Pravin Prasad

1st Year Resident, MD Clinical PharmacologyMaharajgunj Medical Campus

20th December, 2015 (Poush 5, 2072), Sunday

Previous Class…

Resuscitation

Risk Assessment

Supportive Care and Monitoring

InvestigationsDecontamination

Enhanced Elimination Antidotes Disposition

Few Toxidromes

Syndrome caused by a dangerous level of toxins in the body.

Cholinergic ToxidromeSymptoms:

Killer B's: Bradycardia, Bronchorrhea and Bronchospasm

SLUDGE: Salivation, Lacrimation, Urination, Diarrhoea, & Gastrointestinal (Emesis)

DUMBBELLSS: Diarrhoea, Urination, Miosis, Bradycardia, Bronchospasm, Emesis, Lacrimation, Lethargy, Salivation and Seizures

Common Substances:CarbamatesMushroomsOrganophosphates

Complications: Rapid onset of

respiratory failure Seizures Dehydration Neurological sequelae

Cholinergic Toxidromes: Management

Resuscitation• ABCDE• Objective Signs of

Cholinergic Crisis: Atropine

Risk Assessment• Agent(s), Dose(s),

Time since ingestion

• Clinical features and progress

• Patient factors and co-morbidities

Supportive Care• Well ventilated

Room• Universal

Precautions• Intravenous

Fluids• Catheterization

Investigations• Screening:

Cholinesterase levels

• Specific: ECG, Chest X-ray, Electrolytes, renal function, ABG

Decontamination• Should never be

at higher priority than resuscitation

• Activated Charcoal

Elimination Antidotes• Atropine• Pralidoxime (Only

for organophosphates)

Anti-Cholinergic ToxidromesSymptoms:

Agitated Delirium Signs Of Peripheral

Muscarinic Blockade: Blurred Vision, Coma, Decreased Bowel Sounds, Delirium, Dry Skin, Fever, Flushing, Hallucinations, Ileus, Memory Loss, Mydriasis (Dilated Pupils), Myoclonus, Psychosis, Seizures, & Urinary Retention

Substances: The four "anti"s: Antihistamines, Antipsychotics, Antidepressants, and Antiparkinsonian drugs

Atropine, Benztropine, Datura, and Scopolamine.

“Blind as a bat, mad as a hatter, red as a beet, hot as Hares, dry as a bone, the bowel and bladder lose their tone, and the heart runs alone.”

Complications: Hypertension,

Hyperthermia, and Tachycardia

Anti-cholinergic Toxidrome: ManagementResuscitation• ABCDE

Risk Assessment• Agent(s),

Dose(s), Time since ingestion

• Clinical features and progress

• Patient factors and co-morbidities

Supportive Care• Quiet, Well lit Room• Intravenous Fluids• Catheterization• Diazepam for

agitation• Avoid

Anticholinergic agents

Investigations• Screening: ECG• Specific: Drug

levels, Electrolytes, renal function, ABG

Decontamination• Activated

Charcoal

Elimination Antidotes• Physostigmine

(to confirm the diagnosis; if adequate sedation not achieved)

Sympathomimetic Toxidrome Symptoms:

Anxiety, Delusions, Diaphoresis, Hyperreflexia, Mydriasis, Paranoia, Piloerection, And Seizures, Hyperactive Bowel Sounds, Sweating

Seen within 2hrs post ingestion; life threatening complications seen within 6hrs post ingestion

Complications: Hypertension & Tachycardia

Substances Involved: Salbutamol, Cocaine, Amphetamines, Ephedrine (Ma Huang),

Methamphetamine, Phenylpropanolamine (PPA's), & Pseudoephedrine

Sympathomimetic Toxidromes: Management

Resuscitation• ABCDE• Diazepam for

seizure, agitation

Risk Assessment• Agent(s), Dose(s),

Time since ingestion• Clinical features and

progress• Patient factors and

co-morbidities

Supportive Care• Well ventilated

Room• Intravenous Fluids• Catheterization• Diazepam for

agitation• Ambient cooling

Investigations• Screening: ECG

(MI)• Specific: Drug

levels, Electrolytes, renal function, ABG, CT Scan

Decontamination• Activated

Charcoal• Whole bowel

irrigation• Laparotomy

Elimination Antidotes• No Antidotes

Sympatholytic Toxidromes Symptoms:

Vasodilation, reflex tachycardia, hypotension +/- evidence of poor perfusion

CCBs and BBs: CVS: bradycardia, hypotension, AV block, heart failure; CNS: lethargy, confusion, seizures, coma (generally secondary to the CVS effects)

Digoxin: increased automaticity (e.g. PVCs, PACs and other dysrhythmias)

Agents: α1 blockers, β blockers, α2 agonists, calcium channel blockers

Sympatholytic Toxidromes: Management

Resuscitation• ABCDE

Risk Assessment• Agent(s), Dose(s),

Time since ingestion

• Clinical features and progress

• Patient factors and co-morbidities

Supportive Care• Intravenous Fluids• Catheterization• Vasopressors• Calcium• Glucagon

Investigations• Screening: ECG

(MI)• Specific: Drug

levels, Electrolytes, renal function, ABG, CT Scan

Decontamination• Activated

Charcoal• Whole bowel

irrigation• Lapratomy

Elimination Antidotes• No Antidotes

Opioid Withdrawal: ToxidromesSymptoms:

Intense craving, dysphoria, autonomic hyperactivity and gastrointestinal distress.

Anxiety, restlessness and dysphoria; Insomnia; Intense craving; Yawning; Lacrimation; Salivation; Rhinorrhoea; Anorexia, nausea and vomiting; Abdominal cramps and diarrhoea; Mydriasis; Piloerection; Diaphoresis; Flushing; Myalgia and arthralgia; Hypertension and tachycardia in severe cases.

Altered mental status, delirium, hyperthermia and seizures: LOOK FOR COMPLICATIONS/ DIFFERENTIALS

Opioid Withdrawal: ManagementEarly Management:

Safe cessation or dose reduction Management of symptoms and medical complications Retention of patient in treatment program

Pharmacologic Treatment: Opioid Replacement Therapy: Methadone 20-40mg/day, then tapered; Buprenorphine 4-16mg/day

Antagonist Detoxification: Rapid detoxification (naltrexone, buprenorphine and clonidine under close clinical supervision; Ultra Rapid: not recommended

Opioid Withdrawal: Management (Supportive Care)

Paracetamol OverdoseToxic Dose:

single ingestion >250 mg/kg or >12 g over a 24-hour period >350 mg/kg: severe liver toxicity unless appropriately treated

Clinical features of overdose Nausea, vomiting, malaise, Right upper quadrant pain Liver enlargement and tenderness, Jaundice, confusion (hepatic encephalopathy), bleeding diathesis

Marked elevated LFTs, elevation in hepatic enzymes, hyperammonemia, hypoglycemia, lactic acidosis

Sequale: renal failure, death

Paracetamol Overdose: Management

Resuscitation Risk assessment Supportive Care Investigation: Serum Paracetamol levels (only after 4hrs of ingestion)

Decontamination: Activated Charcoal (1g/kg)

Elimination: Exchange Transfusions; Arteriovenous Hemofiltration, Hemodialysis, Hemoperfusion

Antidote: N-acetylcysteine; 150mg/Kg over 15 min; 50mg/Kg over next 4 hrs; 100mg/Kg over next 16 hrs up to 36hrs

Liver transplantation

With this….We conclude General Pharmacology.

Next Class will be on Sunday, 27th December, 2015 (Poush 12, 2072)

Topic: Autonomic Nervous System (Introduction and Cholinergic Drugs)

Thank you!