Expanding etiology of progressive familial intrahepatic cholestasis

Table 1 Medical management of pruritus in children

Medicine	Dose	Mechanism of action
Cholestyramine	Initial dose: 2 g BID	Ion exchange resin which acts as BA binder in the intestine
	(max dose 24 g/d)	Decreased ileal BA absorption, Increased BA excretion (in feces)
Naltrexone	Initial dose: 0.25-5 mg/kg per day	Opioid antagonist
	(max dose 50 mg/d)	Block the permissive activity on pruritus neuronal signaling
Rifampicin	Initial dose: 5 mg/kg	PXR agonist
		Induces CYP3A4
	(max dose 20 mg/kg per day)	Increases metabolism and renal excretion of pruritogenic substances
		Antibacterial effect may modify intestinal metabolism of pruritogenic substances
Sertraline	Initial dose: 1 mg/kg per day	Serotonin reuptake inhibitor
	(max dose: 4 mg/kg per day)	Proposed mechanism includes increase in central serotonergic tone, which regulates pruritus
Ursodeoxycholic acid	600 mg/m2 per day	Tertiary BA
		Increases bile secretion
		Reduces ileal absorption of hydrophilic BAs

BA: Bile acid; PXR: Pregnane X receptor.