Safe Prescribing — Flashcards

Flashcard 111: _____ poisoning may cause symptoms including: gastrointestinal symptoms, lethargy, confusion and vision changes such as Xanthopsia (yellow-tinted vision)

Answer: Digoxin

Flashcard 112: _____ may be given to patients with suspected TCA overdose if the medication was taken in the past 1-2 hours

Answer: Activated charcoal

Flashcard 113: _____ may be used with senior support AND extreme caution in patients with TCA toxicity if IV hypertonic sodium bicarbonate fails

Answer: Class Ib anti-arrhythmics (e.g., Lidocaine)

Extra: Class Ia and Ic anti-arrhythmics are contraindicated in TCA toxicity as they further prolong the QRS interval and worsen sodium channel blockade. Lidocaine (Class Ib) is sometimes considered in refractory arrhythmias.

Flashcard 114: Patients with suspected digoxin toxicity should have an _____, serum digoxin, and U&Es

Answer: ECG

Flashcard 115: The most important inhibitory effects of TCA toxicity are _____ inhibition and muscarinic ACh receptor inhibition

Answer: sodium channel

Flashcard 116: How can serotonin syndrome be differentiated from other drug-induced hyperthermias? _____

Answer: Serotonin syndrome causes neuromuscular excitability (hyperreflexia & myoclonus - particularly lower limbs)

Flashcard 117: Recreational drugs such as _____ and cocaine may cause serotonin syndrome

Answer: Ecstasy (MDMA)

Flashcard 118: TCA toxicity causes inhibition of _____ receptors, muscarinic receptors, histamine receptors, sodium channels

Answer: alpha-adrenergic

Flashcard 119: _____ and widened QRS (>100ms) are found in patients with TCA toxicity?

Answer: Prolonged QTc interval

Flashcard 120: _____ and hypomagnesaemia may occur in patients with digoxin toxicity

Answer: Hyperkalaemia

Extra: Digoxin toxicity: 1. Causes **hyperkalaemia** (blocks Na+/K+ ATPase, preventing K+ entry into cells). 2. **Hypomagnesaemia** increases sensitivity to digoxin, increasing risk of toxicity. 3. Note: While hyperkalaemia is a *consequence*/prognostic marker of toxicity, hypokalaemia and hypomagnesaemia *exacerbate* the effect of digoxin.