What is the amount of lactulose (a laxative medication) in 5.2 milliliters (ml) in grams?

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Lactulose Concentration: 5.2 ml Equals 3.47 Grams

5.2 ml of lactulose solution contains 3.47 grams of lactulose.

Calculation Explanation

  • According to the FDA drug label, lactulose solution contains 10 grams of lactulose per 15 ml 1
  • Using this concentration, we can calculate the amount of lactulose in 5.2 ml:
    • 10 g ÷ 15 ml = 0.667 g/ml
    • 5.2 ml × 0.667 g/ml = 3.47 grams of lactulose 1

Clinical Context of Lactulose Dosing

  • Lactulose is a synthetic disaccharide not digested in the small intestine that exerts an osmotic laxative effect in the colon 2
  • For chronic idiopathic constipation, the initial recommended dose is 10-20 g (15-30 ml) daily 2, 3
  • The dose may be increased to 40 g (60 ml) daily if needed for constipation management 2, 3
  • For hepatic encephalopathy, higher doses are typically used: 20-30 g (30-45 ml) administered 3-4 times daily 4, 5

Dosing Considerations and Side Effects

  • Bloating and flatulence are common dose-dependent side effects that may limit clinical use 2, 3
  • Excessive use can lead to complications including dehydration, hypernatremia, and severe perianal skin irritation 4, 3
  • In patients with liver disease, overuse may paradoxically precipitate encephalopathy 5
  • Dosing should be adjusted based on clinical response with the goal of achieving 2-3 soft bowel movements per day 3

Formulation Details

  • Lactulose solution also contains small amounts of galactose (less than 1.6 grams per 15 ml), lactose (less than 1.2 grams per 15 ml), and fructose (0.1 grams or less per 15 ml) 1
  • The chemical name for lactulose is 4-O-β-D-galactopyranosyl-D-fructofuranose with a molecular weight of 342.30 1
  • It is freely soluble in water 1

Research Findings

  • Studies have shown that lactulose can improve cognitive function as measured by the Animal Naming Test in patients with cirrhosis 6
  • Even subclinical dosages of 5 g daily for 5 days can exert beneficial prebiotic effects 7
  • Lactulose has been shown to decrease fecal ammonia concentrations while increasing total nitrogen excretion 8

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Guideline

Lactulose Dosage and Administration

Praxis Medical Insights: Practical Summaries of Clinical Guidelines, 2025

Guideline

Lactulose Dosage and Administration Guidelines

Praxis Medical Insights: Practical Summaries of Clinical Guidelines, 2025

Guideline

Lactulose Dosing for Hepatic Encephalopathy

Praxis Medical Insights: Practical Summaries of Clinical Guidelines, 2025

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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