Therapeutics + Toxicology Flashcards
Anion gap is calculated as:
(Sodium + potassium) - (chloride + bicarbonate)
Ethylene glycol toxicity - blood gas
Metabolic acidosis with high anion gap and high osmolar gap
Management of Ethylene glycol toxicity
Fomepizole
An inhibitor of alcohol dehydrogenase
Local anesthetic toxicity can be treated with:
IV 20% lipid emulsion
AIT type 1
Excess iodine-induced thyroid hormone synthesis
Goitre - Present
Carbimazole or potassium perchlorate
AIT type 2
Amiodarone-related destructive thyroiditis
Goitre - Absent
Corticosteroids
Management of Malignant hyperthermia
Dantrolene
Prevents Ca2+ release from the sarcoplasmic reticulum
Management of Cyanide poisoning
Supportive measures:
100% oxygen
Definitive:
hydroxocobalamin (intravenously),
Also combination of amyl nitrite (inhaled), sodium nitrite (intravenously), and sodium thiosulfate (intravenously)
Management of cocaine toxicity
Benzodiazepines
Beta Blockade is contraindicated in CVS problems
Overdoses that can be dialysed
BLAST
Barbiturates
Lithium
Alcohols e.g. ethylene glycol
Salicylates
Theophyllines
Organophosphate insecticide poisoning - mechanism
Inhibition of acetylcholinesterase leading to upregulation of nicotinic and muscarinic cholinergic neurotransmission
Management of Organophosphate insecticide poisoning
Atropine
Drugs causing lung fibrosis
Amiodarone
Cytotoxic agents: busulphan, bleomycin
Anti-rheumatoid drugs: methotrexate, sulfasalazine
Nitrofurantoin
Ergot-derived dopamine receptor agonists (bromocriptine, cabergoline, pergolide)
Trastuzumab
(Herceptin) is a monoclonal antibody directed against the HER2/neu receptor
Cardiotoxicity
Inducers of the P450 system
Antiepileptics: phenytoin, carbamazepine
Barbiturates: phenobarbitone
Rifampicin
St John’s Wort
Chronic alcohol intake
Smoking
Inhibitors of the P450 system
Antibiotics: ciprofloxacin, erythromycin
Isoniazid
Cimetidine, Omeprazole
Amiodarone
Imidazoles: ketoconazole, fluconazole
SSRIs: fluoxetine, sertraline
Sodium valproate
Acute alcohol intake
Osmolar gap
Measured osmolality - calculated osmolality
Calculated osmolality
2Na + glucose + urea
DRESS syndrome
Drug Reaction with Eosinophilia and Systemic Symptoms
Management of cocaine toxicity
Benzodiazepines are generally first-line
What medication to avoid in cocaine induced coronary vasospasm.
Beta Blockers
Organophosphate poisoning - MOA
Inhibition of acetylcholinesterase leading to upregulation of nicotinic and muscarinic cholinergic neurotransmission
Management of Serotonin syndrome
Supportive including IV fluids
Benzodiazepines
More severe cases are managed using serotonin antagonists such as cyproheptadine and chlorpromazine
Drugs causing lung fibrosis
Amiodarone
Cytotoxic agents: busulphan, bleomycin
Anti-rheumatoid drugs: methotrexate, sulfasalazine
Nitrofurantoin
Ergot-derived dopamine receptor agonists (bromocriptine, cabergoline, pergolide)
What is the appropriate advice to the patient regarding the safe cessation of anabolic steroid use?
Stop immediately - Tapering not required.
Treatment of amiodarone induced thyrotoxicosis type 2
Corticosteroids
Antithyroid drugs are favoured in AIT type 1 - where the pathophysiology involves excess thyroid hormone synthesis stimulated by the iodide load from amiodarone therapy
HIT - management
Heparin anticoagulants must be withheld
Bivalirudin (non-heparin anticoagulant)
HIT - anti-thrombotic or pro-thrombotic?
Pro-thrombotic
Causes of a high osmolar gap include:
Mannitol
Methanol
Ethylene glycol
King’s College Hospital criteria for liver transplantation (paracetamol liver failure)
Arterial pH < 7.3, 24 hours after ingestion
OR
Prothrombin time > 100 seconds
Creatinine > 300 µmol/l
Grade III or IV encephalopathy
Salicylate overdose management
Urinary alkalinization with IV bicarbonate
Haemodialysis
Opioid/opiates overdose management
Naloxone
Benzodiazepines overdose management
Flumazenil
Tricyclic antidepressants overdose management
IV Bicarbonate
Type 1 amiodarone induced thyrotoxicosis - define
Increased production of thyroid hormone, most likely as a result of the excess iodine load administered to the patient as a result of amiodarone treatment
Type 2 amiodarone induced thyrotoxicosis - define
Destructive thyroiditis
ECG changes of TCA poisoning
Sinus tachycardia
Widening of QRS
Prolongation of QT interval
Treatment of Thallium Poisoning
Oral Prussian Blue
Trimethoprim - pregnancy
Avoid for first three months
Reduce ophthalmological complications in Methanol poisoning
Folinic acid
Management for Iron Overdose
Desferrioxamine - a chelating agent
Drugs for Heparin Induced Thrombocytopenia management.
Direct thrombin inhibitor: Argatroban
Danaparoid
Lithium toxicity can be precipitated by:
Any medicines that can impair renal function or induce hyponatraemia:
ACE inhibitors
Diuretics (particularly thiazides including bendroflumethiazide and indapamide)
NSAIDs
Management of Iron overdose
Whole bowel irrigation
Desferrioxamine
