Understanding Cholestatic Pruritus

A recent review (Hepatology 2014; 60: 399-407) sorts out “facts and fiction” with regard to pruritus in cholestasis.

The authors note that for more than 2000 years there has been a search for the potential pruritogen in cholestasis, “when Aretaeus the Cappadocian (2nd century B.C.) stated that ‘pruritus in jaundiced patients is caused by prickly bilious particles.'”

Key points of review:

Pruritus affects a large number of hepatobiliary diseases

  • Hepatocellular cholestasis: intrahepatic cholestasis of pregnancy (ICP), benign recurrent intrahepatic cholestasis (BRIC), progressive familial intrahepatic cholestasis (PFIC1, PFIC2), Hepatitis C
  • Biliary-liver diseases: primary biliary cirrhosis (PBC), primary sclerosing cholangitis (PSC), PFIC3, Alagille, Drug-induced diseases
  • Obstructive cholestasis: gallstones, IgG4-associated cholangitis, biliary atresia, and other causes

Most recently lysophosphatidic acid LPA) and autotaxin (ATX) have been shown to be important pruritogen candidates in cholestasis

  • “ATX is the main source of circulating LPA levels…In cholestasis, serum ATX activity, but not other putative markers of itch such as serum bile salt levels or serum μ-opiod activity, were correlated with itch intensity.”
  • “Rifampicin was found to reduce ATX expression at the transcriptional level.”  This may explain rifampicin’s efficacy for pruritus in cholestasis.
  • “When the enterohepatic circulation is interrupted by nasobiliary drainage, circulating levels of ATX rapidly dropped concomitant with relief of pruritus.”  So, while ATX is not secreted into bile, other substances in bile, like steroid hormones, like play a role in the induction of ATX.

Current therapeutic recommendations (dosing recommendations provided by authors in Table 3)

  • 1st line: Cholestyramine (except in ICP in which ursodeoxycholic acid is considered 1st line)
  • 2nd line: Rifampicin
  • 3rd line: naltrexone
  • 4th line: sertraline
  • Experimental: ondansetron, phenobarbitol, propranolol, lidocaine, dronabinol, butorphanol, phototherapy, nasobiliary drainage, plasmapharesis (and similar treatments), biliary diversion
  • Liver transplantation

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Disclaimer: These blog posts are for educational purposes only. Specific dosing of medications/diets (along with potential adverse effects) should be confirmed by prescribing physician/nutritionist.  This content is not a substitute for medical advice, diagnosis or treatment provided by a qualified healthcare provider. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a condition.

Severe Pruritus with Alagille Syndrome

A recent study reviews the King’s College experience for managing pruritus associated with cholestasis in patients with Alagille syndrome (AGS) (JPGN 2013; 57: 149-54).

This retrospective study examined 62 patients (1995-2010). 82% (n=51) had pruritus.  Most common treatments:

  • Ursodeoxycholic acid in 40 patients. 1st line Rx in 31. Efficacy was rated as good in 20% and some efficacy in 67.5%.
  • Rifampicin in 39 patients. 1st line Rx in 8. Efficacy was rated as very good/good in 49% and some efficacy in 46%.
  • Cholestyramine in 18 patients. 1st line Rx in 9. Efficacy was rated as  very good in 17% and some efficacy in 67%.
  • Naltrexone in 14 patients. Efficacy was rated as good in 43% and some efficacy in 36%.
  • Alimemazine in 13 patients
  • Nonsedating antihistamines in 7 patients
  • Ondansetron in 5 patients
  • Phenobarbital in 1 patient.

Despite these medications, pruritus was controlled by medication in 41% (n=21).  16 patients were referred for liver transplantation and 11 of these patients have been transplanted.  These 11 patients make up 55% of those who had permanent resolution of their pruritus.

The authors proposed an algorithm for treatment:

  • 1st line: ursodeoxycholic acid 10-20 mg/kg/day divided in 2 doses or cholestyramine 240 mg/kg/day divided into 3 doses
  • 2nd line: (if needed) Add/substitute rifampicin 5-10 mg/kg/day divided into 2 doses (max 600 mg/day)
  • 3rd line: (if needed) Add/substitute naltrexone 0.25-0.5 mg/kg/day (max 50 mg/day)
  • 4th line: (if needed) Add/substitute ondansetron max 8 mg/day divided into 2 doses per day (or phenobarbital 5-10 mg/kg/day divided into 2 doses.
  • If none of these are helpful, options could include MARS (molecular adsorbent recirculation system), partial external biliary diversion, or liver transplantation.

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Increased bile acids in diarrhea-predominant IBS

The role for bile acids in causation of irritable bowel gets a closer look in a recent publication (Clin Gastroenterol Hepatol 2012; 10: 1009-15).

This study randomly selected 52 participants (26 with diarrhea-predominant IBS, 26 with constipation predominant IBS) from a cohort of 700 IBS patients followed at the Mayo clinic along with 26 healthy volunteers.  The ages of the patients ranged from 29-51. Subsequently, these patients underwent additional testing following a 4-day high fat diet.  Of note, 5 of the IBS-D patients had a history of cholecystectomy compared with one patient in the other two groups.

In these patients, bile acid concentrations were measured in the stool and serum levels of 7α-hydroxy-4-cholesten-3-one (C4).In the IBS-D patients, serum levels of C4 were significantly higher than in the other two groups.  38% of the IBS-D group had elevated C4 levels; these elevated levels correlated with increased stool concentrations of bile acids.

The authors note that bile acid malabsorption has been identified frequently in patients with unexplained chronic diarrhea and that these patients often respond to bile acid sequestration (eg. cholestyramine or colesevelam).  Another interesting finding was that obesity was associated with elevated bile acid levels. Overall, the cohort with IBS-D had an average BMI of 29.5.

So, what conclusions can be drawn?

  • Serum C4 levels may be using in identifying patients with bile acid malabsorption
  • Bile acid sequestration agents may be worth a try in some cases of IBS-D and this study provides a rationale

Additional references:

-Alim Pharmacol Ther 2009; 30: 707-17.  Bile acid malabsorption in IBS-D.