2003A04 Outline the potential problems associated with additives used to make medicines suitable for intravenous injection.

 

List:

·     Table: problem, drug, culprit, purpose

·     Logistical problems

 

Ingredient problems:

 

Drug

Purpose

Problem

Sodium metabisulfite

Lignocaine, adrenaline

Anti-oxidant, anti-microbial

·  Anaphylaxis

Egg lecithin

Propofol

Emulsifier

·  ?Anaphylaxis

·  Protein deplete; theoretical risk

Benzethonium chloride

Ketamine

Antimicrobial

·  ?Neurotoxicity

Propylene glycol

Etomidate, diazepam, digoxin, phenytoin

Solubiliser

·  Pain on injection

·  Thrombophlebitis

Soybean oil

Propofol

Solubiliser

·  Lipotoxicity

·  Bacterial contamination risk

·  Propofol infusion syndrome

Mannitol

Paracetamol

Tonicity

·  Osmotic diuresis

Glycine

Remifentanil

Bulk agent

·  Neurotoxic (not for intrathecal use)

↑pH, ↑concentration

Thiopentone

 

·  Precipitation if intra-arterial injection

·  Necrosis if extravasation

·  Precipitation with acidic drugs e.g. suxamethonium

 

Logistical problems:

·       Shelf life

·       Cost