1 itchiness (pruritus). 2  Pruritus is the primary symptom of cholestasis and is thought to be due to interactions of serum bile acids with opioidergic nerves. 3  In fact, the opioid antagonist naltrexone is used to treat pruritus due to cholestasis.ile is secreted by the liver to aid in the digestion of fats. Bile formation begins in bile canaliculi that form between two adjacent surfaces of liver cells (hepatocytes) similar to the terminal branches of a tree.