Inflammatory bowel disease: adherence to immunomodulators in a biological therapy era

Combination therapy, with anti-tumor necrosis factor-α agents and immunomodulators, is the most effective option to induce and maintain remission in inflammatory bowel disease (IBD). Infliximab, with its administration features, determines particular conditions of adherence; the same is not possible with thiopurines. Nevertheless, research on adherence to these treatments is scarce. Nonadherence worsens the prognosis of IBD.

(a) Assess adherence to immunomodulators and (b) determine therapeutic nonadherence predictors.

We included all IBD outpatients consecutively evaluated over a 6-month period in our center. Participants completed a study-specific questionnaire on IBD, IBD therapeutic adherence (Morisky Medication Adherence Scale-8-item), Therapeutics Complexity questionnaire, Beliefs about Medication questionnaire, and Hospital Anxiety and Depression Scale.

A total of 112 patients under azathioprine were considered; 49.1% were also under anti-tumor necrosis factor-α. Self-assessed questionnaire showed that 70.5% were adherent to immunosuppression. Similar adherence was found with and without infliximab (68.4%-monotherapy vs. 72.7%-combination therapy; P=0.61). Nonintentional nonadherence was documented in 57.6%; 42.4% reported voluntary nonadherence. Nonadherence was higher in male patients [odds ratio (OR): 3.79; 95% confidence interval (CI): 1.2-11.95; P=0.023], younger patients (OR: 0.93; 95% CI: 0.87-0.98; P=0.01), nonsmokers (OR: 4.90; 95% CI: 1.22-19.73; P=0.025), and those who had depression (OR: 2.22; 95% CI: 1.36-3.62; P=0.001). Most of the IBD patients believed in the necessity of maintaining immunosuppression (86.7%), but 36.6% reported concerns about drugs.

Nonadherence to thiopurines plays a significant role in IBD. Nonetheless, it does not increase with association with biological agents. Involuntary nonadherence is higher. Male sex, younger age, nonsmoker, and presence of depression were independent predictors of nonadherence to immunomodulators. More than one-third of IBD patients had concerns about drugs. Optimizing the discussion on patients' concerns to overcome perceptual barriers related to drugs may obviate the negative course of IBD related to nonadherence.