Dr Sanjoy Banerjee evaluated how use of thiopurines is altered by thiopurine methyltransferase levels and drug dose adjustment guided by a mercaptopurine metabolite assay.
The researchers further examined whether these resulted in better selection of the drug dose, improved control of disease, and decreased corticosteroid use in pediatric inflammatory bowel disease (IBD).
The team conducted a retrospective review of 101 pediatric patients with IBD receiving a stable dose of azathioprine for 4 months or longer.
Group 1 consisted of 64 patients who received azathioprine and had their metabolite levels measured.
|Disease exacerbations per patient per year was 55% less in Group 1|
|Journal of Pediatric Gastroenterology & Nutrition|
Group 2 included 37 patients who were receiving azathioprine before the availability of metabolite measurement.
The thiopurine methyltransferase level was measured in study group patients before starting azathioprine.
Patients with normal thiopurine methyltransferase level received a higher starting dose of azathioprine than in patients who were heterozygous for thiopurine methyltransferase deficiency.
Patients in Group 1 received a higher starting dose and a higher final dose of azathioprine compared with patients in the comparison group.
The team noted that patients in Group 1 also had more dose adjustments.
The number of disease exacerbations per patient per year was 55% less in Group 1.
The researchers found that patients in Group 1 received less prednisone, and had lower disease activity scores.
There was no difference between groups in infliximab use or surgery rate.
Dr Banerjee's team concludes, “Azathioprine dose adjustment using a mercaptopurine metabolite assay was associated with use of higher doses, improved control of disease and decreased corticosteroid use in pediatric patients with IBD.”