Efficacy and safety of low-dose tetracycline, amoxicillin quadruple therapy in Helicobacter pylori infection: A retrospective single center study

Table 3 Adverse events in the different treatment groups

Adverse effect	All	500 mg bid (n = 73)	500 mg tid (n = 74)	750 mg bid (n = 71)	P value
Total, n/N (%)1	22.5 (49/218)	12.3 (9/73)	31.1 (23/74)	23.9 (17/71)	0.023
Taste distortion	1	0	1	0
Belching	1	0	1	0
Loss of appetite	3	0	1	2
Nausea	5	1	3	1
Vomiting	4	1	1	2
Abdominal pain	1	0	1	0
Bloating	3	0	3	0
Diarrhea	3	1	0	2
Skin rash	4	2	1	1
Fever	3	0	1	2
Dizziness	3	1	1	1
Melena	2	0	1	1
Constipation	2	0	1	1
Abdominal discomfort2	14	3	7	4

¹The symptoms of a single adverse event are counted as 1, and a patient may have multiple adverse events.

²Abdominal discomfort, but not specified.

P values were from two-sided comparisons of the differences among the three treatment groups. 500 mg bid: Tetracycline twice daily; 500 mg tid: Tetracycline three times daily; 750 mg bid: Tetracycline twice daily. N: Number of total patients; n: Number of patients with adverse events.