DCAS Pharmacology for Paramedics 4

Question 1

The antidote for organophosphate poisoning in the pre-hospital setting is:

Accepted Answer

Atropine (large doses) plus pralidoxime (2-PAM) — to reverse muscarinic effects and reactivate cholinesterase

Answer

Organophosphates inhibit acetylcholinesterase, causing cholinergic toxidrome; atropine blocks muscarinic effects (secretions, bronchospasm, bradycardia), while pralidoxime reactivates the enzyme before ageing occurs.

Question 2

The therapeutic effect of heparin administered in pre-hospital ACS management is:

Accepted Answer

Inhibition of Factor Xa and thrombin, preventing thrombus propagation

Answer

Heparin (unfractionated or LMWH) potentiates antithrombin III to inhibit thrombin and Factor Xa, preventing further clot growth in the culprit coronary artery while fibrinolysis or PCI provides definitive reperfusion.

Question 3

Calcium gluconate IV is indicated in the pre-hospital setting for:

Accepted Answer

Hyperkalaemia causing cardiac arrhythmia, or calcium channel blocker overdose — membrane stabilisation

Answer

IV calcium stabilises cardiac myocyte membranes in hyperkalaemia (reducing arrhythmia risk without lowering potassium) and reverses negative cardiac effects of calcium channel blocker overdose through receptor competition.

Question 4

Midazolam's advantage over diazepam for pre-hospital seizure management includes:

Accepted Answer

IM, intranasal, and buccal routes of administration — more options than IV-dependent diazepam

Answer

Midazolam can be given IM, intranasally, or buccally without IV access, providing rapid effective benzodiazepine therapy even when venous access is unavailable — a major practical advantage in seizure management.

Question 5

In the management of suspected cyanide poisoning (e.g., in fire victims with altered consciousness), the antidote is:

Accepted Answer

Hydroxocobalamin (Cyanokit) IV — binds cyanide to form cyanocobalamin (vitamin B12)

Answer

Hydroxocobalamin binds cyanide ions directly, forming non-toxic cyanocobalamin (vitamin B12) which is renally excreted; it is safe, effective, and compatible with concurrent 100% oxygen administration.

DCAS Practice Test

DCAS Practice Test

DCAS Pharmacology for Paramedics 4