A patient with cirrhotic liver is not tolerating proteins. Which drug should a nurse think of prescribing for the patient?

Appeared in: NHM MP Staff Nurse - 2015

Explanation

In liver cirrhosis, protein breakdown leads to increased ammonia (NH₃) production, which the failing liver cannot detoxify, causing hepatic encephalopathy.
Lactulose is a synthetic disaccharide that is not absorbed in the small intestine.
In the colon, bacteria metabolize lactulose into acidic compounds, lowering the gut pH.
The acidic environment converts absorbable ammonia (NH₃) into non-absorbable ammonium (NH₄⁺), which is then trapped in the colon.
Lactulose also acts as an osmotic laxative, increasing stool frequency and promoting the excretion of the trapped ammonium, thereby lowering blood ammonia levels.

Option B: Folic acid is a B-vitamin used to treat anemia. It has no role in reducing blood ammonia levels.
Option C: Thiamine (Vitamin B1) is essential for carbohydrate metabolism and nerve function but does not affect ammonia levels.
Option D: 5% Dextrose is a source of water and calories. It does not treat the underlying cause of hepatic encephalopathy.

Clinical Relevance

Nursing practice connection: Use the key finding related to Pharmacological management of hepatic encephalopathy in liver cirrhosis to guide bedside assessment, documentation, and the next nursing action.
A key nursing responsibility is to monitor the effectiveness of lactulose by tracking the number of bowel movements (aiming for 2-3 soft stools per day) and assessing for improvements in the patient's mental status.
Nurses must monitor for side effects of lactulose, such as dehydration, hypokalemia, and hypernatremia, due to its laxative effect.
Patient education should include the importance of adhering to the medication regimen to prevent episodes of confusion and hospitalization.

How to Approach the Question

First, identify the key information in the question: 'cirrhotic liver' and 'not tolerating proteins'.
Recognize that protein intolerance in a patient with cirrhosis points to hepatic encephalopathy, a condition caused by the accumulation of toxins, primarily ammonia.
The question asks for a drug to manage this situation. Your goal is to identify the medication that reduces ammonia levels.
Evaluate the options: Lactulose is known to lower ammonia. Folic acid and Thiamine are vitamins often given to these patients for other reasons but don't affect ammonia. 5% Dextrose is just sugar water.
Conclude that Lactulose is the only option that directly addresses the pathophysiology of hepatic encephalopathy.

Concept Tested & Keywords

Concept Tested: Pharmacological management of hepatic encephalopathy in liver cirrhosis.
Stem keywords: cirrhotic liver, not tolerating proteins
Lead-in keywords: Which drug
Clinical cues: The phrase 'not tolerating proteins' in a patient with cirrhosis is a strong indicator of developing or existing hepatic encephalopathy due to hyperammonemia.

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E6 Pharmacology KD Tripathi Essentials 9e Part 3 p. 4-6

E6 Nutrition Kumud Khanna 2e pp. 280-282, 276-278

Practise the full NHM MP Staff Nurse - 2015

Attempt every question from this paper in a timed mock, then review the full solution for each one.