Expect to Try Lactulose First for Hepatic Encephalopathy

We’re getting questions about meds for hepatic encephalopathy.

This altered brain function can present as confusion, behavioral changes, or coma. It’s common in patients with liver disease...due to a buildup of ammonia and other toxins usually cleared by the liver.

You’ll play a role in managing common triggers...such as infections, upper GI bleeding, dehydration, constipation, or hypokalemia.

Also plan to treat acute encephalopathy with meds that work in the gut to decrease ammonia production or increase its elimination. But don’t monitor serum ammonia levels...they don’t correlate well with symptoms.

Expect lactulose to be tried first. Plan to give about 20 grams orally or per tube every 1 to 2 hours until the patient has 2 soft bowel movements. Then expect to titrate the frequency or dose so patients have 2 to 3 stools per day.

Mix with water, milk, or juice if patients don’t like the taste.

Be aware that lactulose may cause gas, bloating, or cramps.

Look for rifaximin (Xifaxan) next. This antibiotic works locally in the gut and doesn’t cause a lot of side effects.

Expect it to be added when lactulose isn’t enough...or tried if lactulose isn’t tolerated. This is because there’s limited evidence about routinely using rifaximin alone. Plus it costs about $80/day compared to about $5/day for lactulose.

Feel comfortable crushing rifaximin tabs if needed.

Don’t be surprised if polyethylene glycol (GoLytely) is tried. We’re used to giving this as a colonoscopy prep. But some prescribers may try a bowel purge to clear ammonia from the gut.

In this case, plan to give a one-time dose of 4 liters orally or per tube over 4 hours.

At discharge, verify patients have orders for maintenance lactulose and possibly rifaximin...to help prevent future encephalopathy episodes.

See our chart, Caring for Patients With Hepatic Encephalopathy, for other meds...plus more on prevention and nutrition considerations.

Key References
  • Hepatology 2014;60(2):715-35
  • Mayo Clin Proc 2014;89(2):241-53
  • JAMA Intern Med 2014;174(11):1727-33
  • Br J Nurs 2017;26(13):724-29
Nurse’s Letter. Mar 2019, No. 350330


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