Makindo Medical Notes.com Comprehensive Medical Encyclopedia | Education for Healthcare Professionals

Makindo Medical Notes.com
Download all this content in the Apps now Android App and Apple iPhone/Pad App

MEDICAL DISCLAIMER:The contents are under continuing development and improvements and despite all efforts may contain errors of omission or fact. This is not to be used for the assessment, diagnosis or management of patients. It should not be regarded as medical advice by healthcare workers or laypeople. It is for educational purposes only. Please adhere to your local protocols. Use the BNF for drug information. If you are unwell please seek urgent healthcare advice. If you do not accept this then please do not use the website. Makindo Ltd

Drug Toxicity Assessment and Management

About

Anaesthetics and Critical Care

Obstetrics Gynaecology

Oncology

Ophthalmology

Oral Medicine and Dentistry

Statistics and Research

Stroke

Surgery

Toxicology

Trauma and Orthopaedics

Twitter

Urology

Many of these agents may also cause coma or delirium and so clinical signs may assist when history is unavailable.

General Measures when there is diagnostic uncertainty
Staff should protect themselves if concerns such as Organophosphates ABC and give Oxygen if O₂ sats < 94%. GCS < 9 get ITU review. Eye or skin contamination needs appropriate washing or irrigation. ED/First responder should check CBG > 4.0 mmol/L. If unsure give glucose. If opiate toxicity possible then consider Naloxone Get IV access and Bloods. Send a paracetamol/salicylate level Activated charcoal (50 g PO) if toxic amount ingested < 1 hr before (Not ethylene glycol, iron, lithium, mercury, methanol) See Assessing Coma and Management if comatose Check COHb levels on ABG. ABC, Recovery position, high flow O₂. IV fluids. Assessment top to toe. Front and back. Check for Opiate/fentanyl patches and remove them. Get CT Head +/- Neck if unclear. Are there any injuries. Is neck stiff. Look at pupils. Single large suggest ipsilateral coning should be seen on CT. Both small pupils: opiates, GHB, Cholinergic syndrome (OP) Both large pupils: cocaine, TCA, Amphetamine +/- resultant ICH/SAH. Rewarm if hypothermia. Is patient acidotic with anion gap ( Na⁺ – (Cl- + HCO₃-) ) normal 4 to 12mmol/L Normal AG High AG: Alcohol, Methanol, Ethylene glycol, CO, Salicylates, Lactic acidosis, DKA Little harm and much good in giving Naloxone and Glucose if unsure. If no alternative diagnosis on CT consider IV Cefotaxime and IV Aciclovir. Consider LP. Treat Cerebral malaria if travel and blood films suggest. EEG if non convulsive status. If no ceiling of care discuss HDU/ITU. If Sepsis then broad-spectrum antibiotics Differential depends on Context

General Measures when there is diagnostic uncertainty

Staff should protect themselves if concerns such as Organophosphates
ABC and give Oxygen if O₂ sats < 94%. GCS < 9 get ITU review.
Eye or skin contamination needs appropriate washing or irrigation.
ED/First responder should check CBG > 4.0 mmol/L. If unsure give glucose.
If opiate toxicity possible then consider Naloxone
Get IV access and Bloods. Send a paracetamol/salicylate level
Activated charcoal (50 g PO) if toxic amount ingested < 1 hr before (Not ethylene glycol, iron, lithium, mercury, methanol)
See Assessing Coma and Management if comatose
Check COHb levels on ABG.
ABC, Recovery position, high flow O₂. IV fluids.
Assessment top to toe. Front and back.
Check for Opiate/fentanyl patches and remove them.
Get CT Head +/- Neck if unclear.
Are there any injuries. Is neck stiff. Look at pupils.
- Single large suggest ipsilateral coning should be seen on CT.
- Both small pupils: opiates, GHB, Cholinergic syndrome (OP)
- Both large pupils: cocaine, TCA, Amphetamine +/- resultant ICH/SAH.
- Rewarm if hypothermia.
Is patient acidotic with anion gap ( Na⁺ – (Cl- + HCO₃-) ) normal 4 to 12mmol/L
- Normal AG
- High AG: Alcohol, Methanol, Ethylene glycol, CO, Salicylates, Lactic acidosis, DKA
Little harm and much good in giving Naloxone and Glucose if unsure.
If no alternative diagnosis on CT consider IV Cefotaxime and IV Aciclovir. Consider LP. Treat Cerebral malaria if travel and blood films suggest.
EEG if non convulsive status.
If no ceiling of care discuss HDU/ITU. If Sepsis then broad-spectrum antibiotics
Differential depends on Context

Risk factors

Psychiatric illness (depression, schizophrenia)
Male sex
Living alone
Recent bereavement, divorce or separation
Suicide note written
Age > 45
Unemployment
Chronic physical ill health
Drug or alcohol misuse
Previous attempts (violent method)

Clinical Clues

Clinical assessment	Possible cause
Pink rosy colour	Cyanide, carbon monoxide
Cyanosis	Methaemoglobinaemia, e.g. dapsone, amyl nitrite
Nausea, vomiting	Paracetamol overdose, opiates, NSAIDs, Iron toxicity, Salicylates.
Small pupils	Opiates (Coma small pupils), Gamma hydroxybutyrate, Pontine bleed from cocaine, Cholinergic syndrome (Insecticides).
Large pupils	Cocaine, Tricyclic antidepressants, Amphetamines, Anticholinergic syndrome - Atropine, 'Belladonna'.
Severe hypertension	Cocaine, amphetamines.
Severe hypotension	Tricyclic antidepressants, Haloperidol
Bradycardia	Digoxin, Beta Blockers, Calcium channel blockers, opioids.
Tachycardia	TCA, Theophylline, Digoxin, Antihistamines
Hypoglycaemia	Insulin, Sulphonylureas, Alcohol, Quinine, Salicylates.
Hyperglycaemia	Organophosphates, Theophyllines, MAOIs
Hyperventilation	Salicylates
Renal failure	Renal failure, Salicylates, paraquat, ethylene glycol.
Hyperthermia	Serotonin syndrome, Salicylates, Cocaine, Ecstasy, MAOIs, Theophylline.
Hypothermia	CNS depressants, Opioids, Exposure, phenothiazines e.g. Chlorpromazine, barbiturates
RUQ pain/Jaundice	Paracetamol poisoning, Organic solvents.
Abdominal pain	Iron poisoning, lead toxicity, NSAIDs.
Seizures	Mefenamic acid, TCAs, Opioids, Theophylline, Cocaine, Alcohol.
Rhabdomyolysis	Amphetamines.
Myoclonic jerks	GHB, GBL.
Chest pain	Cocaine, Carbon monoxide
Oral ulcers	Corrosives, paraquat
Elevated osmolar gap	Acetone, Mannitol, methanol, Acetone, ethanol, ethylene glycol.
Anion gap metabolic acidosis	Methanol, metformin, renal failure, Diabetic/Alcoholic Ketoacidosis, Iron, isoniazid, Lactic acidosis, Ethylene glycol, cyanide, carbon monoxide, toluene, Salicylates

Specific antidotes

Always check local/national poisons advice and senior help

Drug	Antidote
Digoxin	Digoxin specific Fab antibodies (Digibind)
Iron salts	Desferrioxamine 15 mg/kg/hr IV
Opioids	Naloxone 0.4-2.0 mg IV may need repeated depending on half life of opiate. Naloxone has a short half life
Paracetamol (US Tylenol)	Oral methionine or IV N-acetyl cysteine
Phenothiazine dystonic reactions	Benztropine 1-2 mg IV
Warfarin	Vitamin K 5 mg slow IV and Prothrombin complex concentrates or Fresh Frozen Plasma if PCC not available
Heparin	Protamine
Ethylene glycol	Alcohol or fomepizole
Methanol	Alcohol or fomepizole and folinic acid
Benzodiazepines	Flumazenil 200 mcg over 15 seconds then 100 mcg at minute intervals. Use only with severe respiratory depression. It may provoke seizures. Most benzodiazepine overdoses are 'slept off' with simple observation of ABCs
Beta-Blockers	Severe bradycardia consider Atropine 1-3 mg IV and/or Glucagon 2-10 mg IV bolus
Tricyclic antidepressant	IV sodium bicarbonate
Salicylates	IV sodium bicarbonate
Sulphonylureas	Glucose, Octreotide
Organophosphate	Atropine 2 mg IV every 2 minutes until pulse > 70/min and Pralidoxime 30 mg/kg
Methotrexate/Trimethoprim	Leucovorin/Folinic acid
Insulin/oral hypoglycaemics	Dextrose
Calcium channel blockers	Calcium Chloride/Gluconate
Carbon monoxide	100% Oxygen or hyperbaric oxygen
Drugs causing Methaemoglobinaemia	Methylene blue
Caesium/Thallium poisoning	Prussian blue
Cyanide	Cyanide Kit - Amyl nitrate, Sodium nitriate, Sodium thiosuphate, hydroxycobalamin
Arsenic	Dimercaptosuccinic acid (Succimer), Dimercaprol
Nerve agents	Atropine 2 mg IV every 2 minutes until pulse > 70/min and Pralidoxime 30 mg/kg
Salicylates, methotrexate and the herbicide 2,4-D.	Urinary alkalinisation using IV sodium bicarbonate enhances elimination
Salicylates, Theophylline, Ethylene glycol, Methanol or Carbamazepine.	Haemodialysis

PLEASE NOTE LEGAL ADVICE: The contents are under continuing development and improvements and may contain errors of omission or fact. Feedback vital and always welcome at drokane at gmail.com. This is not to be used for the assessment, diagnosis or management of patients. It should not be regarded as medical advice. It is only for educational purposes. Please adhere to your local protocols. If you are unwell please seek healthcare advice from your doctor. This does not replace senior or specialist advice. If you do not accept this then please do not use the website. If you need medical advice, please consult a doctor or other appropriate medical professional. If you are a medical professional and you need advice then speak to your senior or colleagues.

Makindo