Personalized Dosing for Crohn's Disease Drugs Using Blood Tests

A method for adjusting doses of inflammatory bowel disease medication by measuring specific drug metabolites in a patient's red blood cells to maximize effectiveness while avoiding side effects.

What it covers

This patent describes a way to personalize the dosage of thiopurine drugs, like 6-mercaptopurine, used to treat conditions like Crohn's disease. Instead of using a standard dose for everyone, doctors measure the concentration of two specific metabolites, 6-thioguanine and 6-methyl-mercaptopurine, within the patient's red blood cells. If 6-thioguanine levels are too low, the drug may not be effective, signaling a need to increase the dose. Conversely, if 6-thioguanine or 6-methyl-mercaptopurine levels are too high, it indicates a risk of toxicity, such as liver damage or blood cell suppression, and the dose should be reduced.

What it doesn't cover

• —Does not cover the chemical synthesis or manufacturing of the drugs themselves.
• —Does not cover diagnostic methods that measure drug levels in tissues other than blood cells.
• —Does not cover dosing strategies for non-gastrointestinal immune-mediated disorders.
• —Does not cover the use of genetic testing to predict drug metabolism.

The clever bit

The inventors established specific numerical thresholds for drug metabolites in red blood cells that correlate directly with clinical outcomes, turning a subjective dosing process into a precise, measurable biological feedback loop.

Why it matters

Before this method, doctors often used a trial-and-error approach to dosing, which could lead to ineffective treatment or dangerous side effects. This patent provided a quantitative, evidence-based framework for therapeutic drug monitoring, which is now a standard practice in gastroenterology for managing IBD patients on thiopurine therapy.

Real-world examples

• 1.Therapeutic drug monitoring protocols in pediatric gastroenterology clinics
• 2.Clinical guidelines for managing IBD patients on azathioprine or 6-mercaptopurine