Safe Prescribing — Flashcards

Flashcard 81: An ABG performed on a patient with salicylate poisoning will show mixed respiratory alkalosis & metabolic acidosis. What causes the respiratory alkalosis? _____

Answer: Early stimulation of the respiratory centre

Flashcard 82: Why should opioid overdose patients be monitored closely after naloxone administration?\n_____

Answer: Naloxone has a shorter half-life than most opioids (risk of re-sedation)

Extra: The duration of action of Naloxone is approximately 30-90 minutes, whereas many opioids (like morphine or methadone) have a much longer half-life. Patients may appear to recover but then lapse back into respiratory depression as the naloxone wears off, requiring repeat doses or an infusion.

Flashcard 83: The most characteristic early clinical feature of salicylate poisoning is _____

Answer: tinnitus

Extra: Salicylate poisoning (aspirin) typically presents with: 1. CNS: Tinnitus, vertigo, respiratory center stimulation. 2. Acid-Base: Early respiratory alkalosis followed by an elevated anion gap metabolic acidosis (Mixed Disorder). 3. GI: Nausea, vomiting, and gastric irritation. Treatment includes urine alkalinization with sodium bicarbonate.

Flashcard 84: A 21 year old has recently started their second year of university. They have had a headache since moving into a new student house but now presents with altered mental status and pink mucosae. What is the most likely treatment for this patient? _____

Answer: 100% Oxygen via non-rebreathe mask (minimum 6 hours) - Carbon monoxide poisoning

Flashcard 85: Ethylene glycol poisoning is suspected based on clinical presentation and a _____ metabolic acidosis with an increased osmolal gap.

Answer: high anion-gap

Extra: Key findings include: - CNS depression (initial phase) - High anion gap metabolic acidosis (HAGMA) - Increased osmolal gap - Envelope/Needle-shaped calcium oxalate crystals in urine. - Treatment: Fomepizole (DOC) or Ethanol; Dialysis for severe cases.

Flashcard 86: An ABG performed on a patient with salicylate poisoning will show mixed respiratory alkalosis & metabolic acidosis. What causes the metabolic acidosis?\n_____

Answer: Uncoupling of oxidative phosphorylation (leading to lactic acidosis) and accumulation of organic acids

Extra: Salicylate poisoning typically presents with a 'mixed' acid-base disturbance: a primary respiratory alkalosis and a primary elevated anion gap metabolic acidosis. If the pH is normal but CO2 and HCO3 are both low, suspect salicylate toxicity.

Flashcard 87: Inhibition of _____ enzymes in patients taking serotonergic drugs may cause serotonin syndrome

Answer: CYP450

Flashcard 88: Digoxin level blood test should be performed _____ after administration

Answer: 6 hours

Flashcard 89: What is the antidote to _____? Digoxin-specific antibody fragments (e.g. Digibind)

Answer: digoxin toxicity

Flashcard 90: Which condition is associated with ECG findings of a 'reverse tick' (sagging ST-segment depression)?\n\n_____

Answer: Digoxin toxicity

Extra: The characteristic ECG sign of digoxin is 'digitalis effect', seen as sagging ST-segment depression with a 'reverse tick' appearance. Toxicity can manifest as various arrhythmias, most commonly frequent PVCs, atrial tachycardia with AV block, or bidirectional VT.