Dual therapy has been largely discontinued due to low efficacy. In Japan some researchers believe that the rate of H. Pylori eradication through standard dosage triple therapy depends as much on CYP2C19 polymorphisms in individual patients as it depends on bacterial sensitivity to clarithromycin 29.
Investigadores japoneses consideran que, en ese país, la tasa de erradicación de H. pylori con triple terapia estándar IBP, amoxicilina y claritromicina, a dosis usuales, depende tanto de la susceptibilidad bacteriana a claritromicina como del polimorfismo del CYP2C19 del paciente 29.