A mixture of Pancuronium Bromide, Sodium Pentothal and Potassium Chloride

The Life of David Gale


Spokesman: After completion of last words, the injection is administered.
Sodium penthonal for sedation purposes.
Pancuronium bromide to collapse the diaphragm and lungs.
Potassium chloride to stop the heart.



RUNTIME: 130 mins

SYNOPSIS: David Gale (Kevin Spacey) is charged with rape and murder. Now Gale awaits execution, with a fatal injection of pancuronium bromide and potassium chloride.

Pancuronium Bromide

Speed of onset: Intermediate paralysis (2-3 mins)
Duration of action: Long (45-60 mins)

Mechanism of action: Pancuronium is a non-depolarising blocking agent that acts as competitive antagonist at the acetylcholine receptors at the neuromuscular junctions. It is a medium-term muscle relaxant and works by curarimimetic action. The quantity of acetylcholine released by the nerve impulse generally exceeds by that what is needed to elicit an action potential in a specific muscle fibre. Thus it is necessary to block 70-80% of the receptor sites before transmission fails.

Medical use: With the appropriate intravenous dosage of this drug the effects last for approx. 40 minutes, which is used in combination with general anaesthesia during surgery for muscle relaxation. It is also used to optimize conditions for endotracheal intubation and assist ventilation.

Main side effects:

  • Slight tachycardia (increased heart rate and cardiac output)
  • Increased arterial pressure (thus no hypotension)
  • Excessive salivation
  • Apnoea
  • Depression of the respiratory system
  • Rashes
  • Flushing
  • Excessive sweating

This muscular relaxation may be hazardous if given to a patient that is seriously ill and it may accumulate, which in turn can
lead to extended frailty.


Click on the picture above to interact
with the 3D model of the
Pancuronium Bromide structure

Chemical Name: Pancuronium bromide
Brand Name: Pavulon®
3a, 17β - diacetoxy - 5a - androstan - 2β, 16β - ylene bis [1 - methylpiperidinium] dibromide.
Molecular Formula:

Potassium Chloride

Crystal Structure: AX (NaCl - rock salt). Cubic close packing of anions (Cl-) with all octahedral holes filled by cations (K+).

Importance: Potassium (K+) and chloride (Cl-) ions are key ions used within the human body, thus oral potassium chloride is taken to replenish supplies.

Potassium ions are involved in muscle contractions as well as regulating fluid and electrolyte balance in cells within the body. It also keys a key role in the nervous system as it assists in sending nerve impulses. Furthermore it releases stored energy from protein, fat and carbohydrates during the process of metabolism.

Chloride ions play a significant role in the central nervous system and are important in various biochemical systems, for instance GABA relies upon the entry of Cl into particular neurons.

Medical use: Potassium chloride is used to treat hypokalemia, digitalis poisoning, and as an electrolyte replenisher.

Main side effects: Gastrointestinal problems


Click on the picture above to interact
with the 3D model of the
Potassium Chloride structure

Chemical Name: Potassium Chloride
Brand Name: K-Dur®, Klor-Con®, Micro-K®, Kaon Cl®
Molecular Formula: KCl

Execution by Lethal Injection

Pancuronium is used as one component of a lethal injection in capital punishment, within certain regions of the United States. When it is administered with sodium pentothal anaesthetic, it causes this anaesthetic to precipitate, rendering it ineffective.

So as pancuronium effectively collapses the diaphragm and lungs (arrests breathing). A massive overdose of intravenous potassium chloride is also used to stop the heart.

Concern: Pancuronium possesses no sedative or analgesic effects, however the drug prevents the body from displaying pain.

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