Azathioprine, and mercaptopurine are accepted as effective therapy for Crohn's disease, and ulcerative colitis.
General guidelines have been suggested for weight-based dosing of thiopurines, however, no standard of care has been established.
Clinical trials have demonstrated efficacy for weight-based dosing of azathioprine at 2.5 mg/kg/day, and mercaptopurine at 1.5 mg/kg/day.
Escalation of dosing is recommended within 2 weeks of initiating therapy.
Dr Miles Sparrow and colleagues from Australia determined the prescribing practices of community practice gastroenterologists with respect to mercaptopurine/azathioprine dosing.
|24% of gastroenterologists escalated the dose within 2 weeks after initiating therapy|
|Inflammatory Bowel Diseases|
The research team distributed questionnaires via a mail database or during gastroenterology society meetings to gastroenterologists.
Questionnaires ascertained starting doses of azathioprine/mercaptopurine, use of thiopurine methyltransferase enzyme testing, and strategy for dose optimization.
The researchers collected 145 questionnaires.
A total of 24% of gastroenterologists escalated the dose within 2 weeks after initiating therapy.
The majority used weight-based dosing as their target of therapy.
The research team noted that 35% reported measuring thiopurine methyltransferase levels, and 46% used metabolite monitoring.
Dr Sparrow's team concluded, "Most gastroenterologists take longer than recommended to raise the dose of azathioprine/mercaptopurine."
"Although the majority of gastroenterologists reported maximal dosages based on weight, there may be a delay in achieving this goal."
"Optimizing dosing of azathioprine/mercaptopurine may improve efficacy, and reduce the need to use additional therapy."