Therapy

Why?

• Patients with sickle cell disease who have levels of norpethidine >1.0mcg/l (a toxic metabolite of pethidine) are at increased risk of fitting. ^c

Pethidine increases the risk of a seizure

Outcome	Risk Factor	Peer	OR (95% CI)	NNH (95% CI)
fit c	norpethidine >1.0 mcg/l not independent	-%	- (5.5 to infinity)	1 (1 to 200)