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...
