How does Crohn's disease affect medication absorption?

From the Guidelines

Crohn's disease significantly impairs medication absorption due to inflammation, ulceration, and damage to the intestinal lining, which reduces the gut's ability to properly absorb oral medications. The disease can affect individuals of any age and may cause significant morbidity and impact on quality of life 1. Medications particularly affected include immunosuppressants like azathioprine, corticosteroids, and certain antibiotics.

Factors Affecting Medication Absorption

• Inflammation and ulceration of the intestinal lining damages the absorptive surface area
• Increased gastrointestinal motility during disease flares can cause medications to pass through the digestive tract too quickly, limiting absorption time
• Extensive small bowel involvement or previous intestinal resection surgeries further reduce the available surface area for drug absorption
• Medications that require specific intestinal regions for absorption, such as extended-release formulations, are particularly problematic

Alternative Medication Routes and Formulations

• Patients with Crohn's may require alternative medication routes (intravenous, subcutaneous, or topical) to ensure therapeutic effectiveness
• Adjusted dosages or different drug formulations may be necessary, such as selecting mesalamine formulations based on disease location
• Antibiotics might require intravenous administration during severe flares
• Combination therapy with infliximab and an immunomodulator, such as azathioprine or methotrexate, may be beneficial in reducing immunogenicity and improving treatment outcomes 1

Malabsorption and Nutrient Deficiencies

• Malabsorption issues can also affect nutrient absorption, potentially leading to deficiencies that further complicate medication metabolism and effectiveness
• Patients with Crohn's disease may require monitoring for nutrient deficiencies and supplementation as needed
• The use of biologic therapies, such as infliximab, may be considered for patients refractory to immunomodulator therapy, with the choice of therapy made on an individual basis 1

From the Research

Medication Absorption in Crohn's Disease

• Crohn's disease is a chronic inflammatory bowel disease that can affect the absorption of medications in the body 2, 3.
• The disease can cause inflammation and damage to the lining of the gut, which can lead to malabsorption of nutrients and medications 4, 5.
• The absorption of medications in Crohn's disease can be affected by the location and extent of the disease, as well as the presence of complications such as strictures or fistulas 5, 6.
• Some medications, such as thiopurines and biologics, may be affected by the disease and require therapeutic drug monitoring to ensure optimal dosing and minimize side effects 2, 6.
• The use of immunomodulators and biologics in the treatment of Crohn's disease may help to reduce inflammation and improve medication absorption, but more research is needed to fully understand their effects 3, 5.

Factors Affecting Medication Absorption

• Disease location and extent: The location and extent of Crohn's disease can affect the absorption of medications, with more extensive disease leading to greater malabsorption 4, 5.
• Presence of complications: Complications such as strictures or fistulas can also affect medication absorption, and may require alternative treatment approaches 5, 6.
• Medication type: Different medications may be affected differently by Crohn's disease, with some requiring therapeutic drug monitoring to ensure optimal dosing 2, 6.
• Individual patient factors: Individual patient factors, such as disease severity and patient wishes, can also affect medication absorption and treatment outcomes 3, 6.