Discussion
Clarithromycin is a first-line drug for H. pylori eradication. It
is reportedly a cytochrome P450 3A4 inhibitor, but that is not in and of
itself a contraindication for porphyria.5,6 There have
been no reports on the safety of metronidazole monotherapy or
combination therapy for H. pylori in patients with
porphyria; and although amoxicillin and vonoprazan are believed not to
induce porphyria attacks, the evidence remains insufficient. We had
previously described how porphyria attacks can be triggered by the
accumulation of porphyrin precursors or the lack of
heme,4 indicating that porphyria attacks may be
prevented by supplying the appropriate amount of hemin. Here, we present
a protocol that can suppress medication-induced porphyria, even in
patients with a history of recurrent acute attacks. More specifically,
we believe this report may serve as a future reference for eradicatingH. pylori in patients with porphyria.