Background and aims: Low-dose naltrexone [LDN] is a controversial off-label treatment used by many Crohn's disease [CD] and ulcerative colitis [UC] patients. A small number of preliminary studies indicate that LDN might be beneficial in CD, but evidence is too scarce to demonstrate efficacy. We sought to examine whether initiation of LDN therapy by patients with inflammatory bowel disease [IBD] was followed by changes in dispensing of relevant medication.
Methods: We performed a quasi-experimental before-and-after study following a sudden increase in LDN use in the Norwegian population in 2013. IBD patients were identified from among all the patients who had at least one LDN prescription recorded in the Norwegian Prescription Database [NorPD] in 2013. Drug dispensing 2 years before and after the first LDN prescription was compared.
Results: We identified 582 IBD patients who had received LDN. Of the 256 patients who became persistent LDN users, there were reductions in the number of users for [i] all examined drugs [-12%], [ii] intestinal anti-inflammatory agents [-17%], [iii] other immunosuppressants [-29%], [iv] intestinal corticosteroids [-32%] and [v] aminosalicylates [-17%]. In subgroups of identified CD and UC patients, there were significant reductions in the number of users of intestinal corticosteroids [CD: -44%, UC: -53%] and systemic corticosteroids [UC: -24%]. No significant differences in cumulative defined daily doses were observed.
Conclusions: Our findings imply that the initiation of LDN in IBD is followed by reduced dispensing of several drugs considered essential in the treatment of CD and UC.