Rifabutin‐based Helicobacter pylori eradication ‘rescue therapy’

SIRS, We read with interest the work by Perri et al. on the efficacy of a rifabutin-based Helicobacter pylori eradication regimen in patients who remained positive after three or more courses of 7-day standard therapies.1 In order to verify rifabutin efficacy and tolerability, we carried out a 10-day trial with the following regimen: omeprazole (20 mg b.d.), amoxicillin (1 g b.d.), rifabutin (300 mg o.m.). All 10 patients (7 male, mean age 36 years) had multiple unsuccessful eradication attempts, and agreed to be submitted to the therapy. We obtained good eradication rates: 77% of patients (7/9) by per protocol analysis and 70% by intention-to-treat analysis (7/10). However, one patient withdrew after 6 days of therapy: he developed fever with a severe leukopenia and trombocytopenia that continued for several days after discontinuation of rifabutin. His absolute WBC count fell below 2000/mm3, and his platelet count fell below 100 000/mm3 at day 7. His bone marrow aspirate indicated that neutropenia was a result of myelotoxicity. His white blood cell count returned to normal at day 15 after discontinuation of therapy. Our results confirm the efficacy of rifabutin in eradicating H. pylori in patients ‘resistant’ to standard regimens, nevertheless physicians should be aware of the risk of major side-effects arising during a rifabutin-based regimen. The myelotoxicity of rifabutin has been described during longer exposure (> 10 days) and at a higher dosage (> 600 mg/day).2, 3 Important drug interactions with commonly-used antibiotics can also be speculated—for example, with clarithromycin in combination therapy, because rifabutin induces cytochrome P-450.4 Finally, since the Italian Ministry of Health and the FDA indications for the use of rifabutin are restricted to prevention or cure of Mycobacterium avium complex disease in HIV-infected patients, the use of this drug outside this indication is questionable.