Table 1.

Recommended first-line therapies for Helicobacter pylori infection.

Treatment	Regimen	High clarithromycin resistance area	Low clarithromycin resistance area
Standard triple therapy	A PPI (standard dose, b.i.d.), clarithromycin (500 mg, b.i.d.), and amoxicillin (1 g, b.i.d.) for 7–14 days	x	V
Bismuth-containing quadruple therapy	A PPI (standard dose, b.i.d.), bismuth (standard dose, q.i.d.), tetracycline (500 mg, q.i.d.), and metronidazole (250 mg, q.i.d.) for 10–14 days	V	V
Sequential therapy	A 5-day dual therapy with a PPI (standard dose, b.i.d.) and amoxicillin (1 g, b.i.d.) followed by a 5-day triple therapy with a PPI (standard dose, b.i.d.), clarithromycin (500 mg, b.i.d.), and metronidazole (500 mg, b.i.d.)	V	V
Concomitant therapy	A PPI (standard dose, b.i.d.), clarithromycin (500 mg, b.i.d.), amoxicillin (1 g, b.i.d.), and metronidazole (500 mg, b.i.d.) for 7–10 days	V	V
Levofloxacin-based triple therapy	A PPI (standard dose, b.i.d.), levofloxacin (500 mg, q.d.), and amoxicillin (1 g, b.i.d.) for 10 days	V	—∗
Hybrid therapy	A 7-day dual therapy with a PPI (standard dose, b.i.d.) and amoxicillin (1 g, b.i.d.) followed by a 7-day quadruple therapy with a PPI (standard dose, b.i.d.), amoxicillin (1 g, b.i.d.), clarithromycin (500 mg, b.i.d.), and metronidazole (500 mg, b.i.d.)	V	V

*Levofloxacin-based triple therapy is useful, but it might not be recommended as first-line therapy under the consideration of rapidly increasing resistance.