Bismuth Subcitrate Dosage for 14-Day Treatment
For a 14-day H. pylori eradication regimen, administer bismuth subcitrate 420 mg (three capsules of 140 mg each) four times daily after meals and at bedtime, totaling 1,680 mg per day. 1
Standard Dosing Protocol
The FDA-approved bismuth quadruple therapy regimen specifies:
- Bismuth subcitrate potassium: 3 capsules (140 mg each = 420 mg total) taken 4 times daily
- Timing: After meals and at bedtime
- Duration: Can be given for either 10 or 14 days
- Co-administration: With PPI (omeprazole 20 mg) twice daily, metronidazole 125 mg, and tetracycline 125 mg (all contained in the same capsule formulation) 1
Duration Considerations: 10 vs 14 Days
While the FDA label supports both 10 and 14-day regimens 1, the 2021 AGA guidelines recommend 14 days for bismuth quadruple therapy with bismuth ~300 mg four times daily, metronidazole 500 mg three times daily, tetracycline 500 mg four times daily, and PPI twice daily 2.
However, recent high-quality evidence shows:
- 10-day regimens achieve non-inferior eradication rates (93.22% per-protocol) compared to 14-day regimens (93.74%), with significantly fewer adverse effects (22.59% vs 28.50%, p=0.016) 3
- Another 2023 study confirmed 90.5% eradication with 10-day twice-daily dosing 4
Practical Dosing Algorithm
For standard patients (body weight <70 kg, treatment-naïve):
For patients with body weight ≥70 kg or reinfection:
- Extend to 14-day regimen 4
For elderly (≥75 years) or drug interaction risk:
- Consider half-dose antibiotics for 14 days, though this shows lower efficacy (83.5% eradication) 4
- Half-dose is more appropriate for drug interaction concerns than age alone 4
Critical Administration Details
- Swallow capsules whole with a full 8-ounce glass of water 1
- Bedtime dose requires adequate fluid to prevent esophageal irritation from tetracycline 1
- Each "dose" = 3 capsules taken together four times daily 1
- Total daily capsules: 12 capsules per day
- If >4 doses missed: Contact healthcare provider 1
Common Pitfall
The guideline notation of "bismuth ~300 mg qid" 2 refers to elemental bismuth content in various formulations. The FDA-approved combination product contains 140 mg bismuth subcitrate potassium per capsule, with 3 capsules (420 mg) taken four times daily being the equivalent therapeutic dose 1.