What is the lactose order for a patient with elevated ammonia levels (hyperammonemia)?

From the Guidelines

For a patient with elevated ammonia levels, I strongly recommend administering lactulose at a dose of 20-30 grams orally 3-4 times per day, as this has been shown to effectively reduce ammonia levels and improve symptoms of hepatic encephalopathy 1. The goal of lactulose therapy is to create an acidic environment in the colon that traps ammonia and promotes its excretion. Lactulose works by being metabolized by gut bacteria to short-chain fatty acids, lowering colonic pH, converting ammonia to ammonium which cannot be reabsorbed, and increasing stool frequency.

Key Considerations

• The dose of lactulose should be titrated to achieve two to three soft stools per day, with a typical maintenance dose of 15-30 mL two to three times per day 1.
• For patients who cannot take oral medication, rectal administration via enema (200 g lactulose mixed with 700 mL water) can be used, and may be performed 3-4 times per day in severe cases 1.
• It is essential to monitor for side effects, including abdominal cramping, bloating, flatulence, and diarrhea, and adjust the dose accordingly to prevent dehydration or electrolyte imbalances.

Alternative Options

• Rifaximin, an antibiotic that reduces the production of ammonia by gut bacteria, may be used in conjunction with lactulose, at a dose of 400 mg three times per day or 550 mg twice per day 1.
• Other therapies, such as oral branched-chain amino acids, intravenous L-ornithine-L-aspartate, and albumin, may also be considered in the management of hepatic encephalopathy, but lactulose remains the first-line treatment due to its efficacy and low cost 1.

From the FDA Drug Label

For the prevention and treatment of portal-systemic encephalopathy, including the stages of hepatic pre-coma and coma. Controlled studies have shown that lactulose solution therapy reduces the blood ammonia levels by 25 to 50%; The lactulose order for a patient with elevated ammonia levels (hyperammonemia) is to administer lactulose solution, as it has been shown to reduce blood ammonia levels by 25 to 50% 2.

• The goal of treatment is to reduce ammonia levels and improve the patient's mental state.
• Lactulose therapy is a suitable option for patients with hyperammonemia due to its ability to lower blood ammonia levels.

From the Research

Lactose Order for Hyperammonemia

• The lactulose order for a patient with elevated ammonia levels (hyperammonemia) is not directly dependent on the ammonia levels, as studies have shown that ammonia levels do not guide clinical management of patients with hepatic encephalopathy caused by cirrhosis 3.
• Lactulose is a mainstay of treatment for hyperammonemia, and is often used in combination with rifaximin to break down ammonia production and decrease ammonia absorption in the gastrointestinal tract 4, 5.
• The dose of lactulose is not correlated with ammonia levels, and the average lactulose dose in patients with elevated ammonia levels is similar to that in patients with normal ammonia levels 3.
• Treatment of hyperammonemia largely depends on the underlying cause, and lactulose is used to establish anabolism and avoid endogenous protein breakdown and amino acid imbalances 6.
• The use of lactulose in patients with hyperammonemia is aimed at reducing ammonia production and absorption, and improving urea cycle function or removing nitrogen 4, 6.