Tuesday, 9 November 2010

MRCP revision battle 44.5: Quinine toxicity/overdose

Quinine is used in the prevention of falciparum malaria and the treatment of nocturnal leg cramps.

It is very toxic in overdose and can be toxic in some individuals at therapeutic doses.
Quinidine, a stereoisomer of quinine and a class Ia antiarrythmic, can be toxic in a single dose.

Signs/symptoms include:
  • tinnitus
  • hearing loss
  • abdominal pain
  • blurred vision
  • hypotension (due to alpha blockade)
  • long QT

There is a risk of irreversible blindness.

Treatment is recurrent doses of activated charcoal and supportive management

Now for another overdose requiring activated charcoal...