Quadruple Therapy for Peptic Ulcer Disease (H. pylori Eradication)

1. Bismuth-Based Quadruple Therapy (BQT)

• Duration: 10 to 14 days (14 days preferred)
• Eradication rate: 90% or higher achievable with first-line use

Key Advantages

• Contains neither clarithromycin nor amoxicillin - avoids both macrolide and penicillin issues
• Not impaired by clarithromycin or fluoroquinolone resistance
• Appropriate for patients with penicillin allergy or macrolide exposure
• Recommended in areas where clarithromycin resistance >15%

Indications for BQT (per Maastricht V, ACG, Toronto Guidelines)

1. First-line empirical therapy in areas of high clarithromycin resistance
2. Second-line therapy after failure of clarithromycin-based triple therapy
3. Patients with prior macrolide exposure (clarithromycin, azithromycin)
4. Patients with penicillin allergy + recent metronidazole use
5. Areas where regional antibiotic susceptibility data is unavailable

• Sabiston Textbook of Surgery, p. 2046-2048
• Yamada's Textbook of Gastroenterology, p. 548-558
• Sleisenger and Fordtran's GI and Liver Disease, p. 2101

2. Non-Bismuth Quadruple Therapy (Concomitant Therapy)

• Duration: 14 days
• Also called "concomitant quadruple therapy" - all four drugs given simultaneously (unlike sequential therapy where they are split into phases)

Variants

• Sequential therapy (historical/less preferred): PPI + amoxicillin for 5 days, then PPI + clarithromycin + metronidazole for 5 days
• Hybrid therapy: PPI + amoxicillin for 7 days, then add clarithromycin + metronidazole for a further 7 days

3. When to Use - Clinical Decision Guide

No penicillin allergy, no prior macrolide, low clarithromycin resistance (<15%):
  → Clarithromycin triple therapy (first-line)
  → OR Bismuth quadruple therapy
  → OR Concomitant regimen

Prior macrolide exposure OR clarithromycin resistance >15%:
  → Bismuth quadruple therapy (preferred)
  → OR Levofloxacin triple therapy

Penicillin allergy only:
  → Clarithromycin triple with metronidazole (instead of amoxicillin)

Penicillin allergy + prior metronidazole use:
  → Bismuth quadruple therapy

• Sabiston Textbook of Surgery, Box 86.1

4. Comparison: BQT vs. Concomitant Therapy

5. Second-Line & Salvage Regimens

• Levofloxacin-based triple therapy (PPI + levofloxacin + amoxicillin, 14 days)
• Rifabutin triple therapy (PPI + amoxicillin + rifabutin) - reserved for multi-drug resistance
• High-dose dual therapy (PPI + amoxicillin, high dose, 14 days)
• Culture-guided, susceptibility-based therapy (gold standard when available)

6. Side Effects

• Diarrhea, nausea/vomiting
• Altered taste (metallic taste with metronidazole)
• Rash
• GI upset

7. Post-Treatment Verification

• Urea breath test (UBT) - preferred non-invasive
• Stool antigen test
• Repeat endoscopy with biopsy (if endoscopy was performed initially)

ORS Composition

WHO Reduced-Osmolarity ORS (2002 Revised Formula)

Electrolyte Composition (per litre)

Harrison's Principles of Internal Medicine 22E, Table 153-3

Packet Contents (to dissolve in 1 litre of drinking water)

Old vs. New (Revised) WHO ORS

Homemade ORS (if packets unavailable)

• ½ teaspoon of salt (~3.5 g NaCl)
• 6 teaspoons of sugar (sucrose) - OR 50 g precooked rice cereal
• Supplement potassium separately (orange juice, coconut water, or banana)

Harrison's 22E, p. 1372; Symptom to Diagnosis 4th Ed., p. 250

Key Points

• Glucose:Na ratio must be 1:1 - exploits the sodium-glucose cotransporter (SGLT1) in enterocytes to drive sodium (and water) absorption even during active secretory diarrhea
• Citrate provides 30 mmol/L of HCO₃⁻ equivalent to correct metabolic acidosis
• ORS does not reduce stool volume but maintains hydration; it is effective for mild-moderate dehydration
• Cannot replace IV fluids in severe dehydration, shock, or inability to drink
• Rice-based ORS is considered superior to standard ORS specifically in cholera (reduces stool output more effectively)
• If ORS unavailable, sports drinks and soup broth are acceptable for mild diarrhea with minimal dehydration

Quadruple Therapy for PUD - KD Tripathi

Tripathi's Quadruple Therapy Regimen

"Quadruple therapy with CBS 120 mg QID + tetracycline 500 mg QID + metronidazole 400 mg TDS + omeprazole 20 mg BD is advocated for eradication failure cases."

• KD Tripathi, Essentials of Medical Pharmacology, 7th Ed., p. 651-658

Context in Tripathi's Classification

• PPI + two antibiotics (e.g., amoxicillin + clarithromycin OR amoxicillin + metronidazole) for 1-2 weeks

• PPI + CBS + tetracycline + metronidazole

• PPI + tetracycline + CBS + metronidazole

Key Points as per Tripathi

1. Indication: Reserved for cases where first-line triple therapy has failed (eradication failure)
2. CBS (bismuth) acts as a local mucosal protective + weak antibacterial against H. pylori
3. Metronidazole should be excluded if the patient has recently received a nitroimidazole for another infection (resistance concern)
4. Similarly, clarithromycin should be excluded if the patient recently received a macrolide
5. For large ulcers (>10 mm) or those complicated by bleeding/perforation, PPI must be continued beyond the 2-week antibiotic course until complete healing
6. Higher failure rates (20-40%) of H. pylori eradication reported specifically from India; 3-week treatment is advocated by some for this reason
7. "All regimens are complex and expensive, side effects are frequent and compliance is poor." - Tripathi's direct note

Mnemonic: BOTM (for Tripathi's Quadruple)

• B - Bismuth (CBS 120 mg QID)
• O - Omeprazole (20 mg BD)
• T - Tetracycline (500 mg QID)
• M - Metronidazole (400 mg TDS)

Triple Therapy for H. pylori / PUD

Standard Triple Therapy (First-Line)

• If penicillin-allergic: replace amoxicillin with Metronidazole 500 mg BD
• After completing antibiotics, continue PPI once daily for 4-6 weeks to ensure complete ulcer healing

"Omeprazole/Lansoprazole 20/30 mg BD + Clarithromycin 500 mg BD + Amoxicillin/Metronidazole 1 g/500 mg BD - given for 14 days followed by PPI for 4-6 weeks"

• KD Tripathi, Essentials of Medical Pharmacology 7th Ed.

All Three Triple Therapy Variants (as per Tripathi)

1. PPI-Based Triple (Most commonly used - first line)

• Omeprazole 20 mg BD + Clarithromycin 500 mg BD + Amoxicillin 1 g BD × 14 days

2. Bismuth-Based Triple (Older regimen, still used)

3. Ranitidine Bismuth Citrate (RBC) Triple

Why PPI is Included

1. Direct weak antimicrobial effect on H. pylori (minor)
2. Raise intragastric pH → lowers minimum inhibitory concentrations (MIC) of clarithromycin and amoxicillin → bacteria become more susceptible and replicatively active

• Katzung's Basic and Clinical Pharmacology 16th Ed., p. 2323

When Triple Therapy Should NOT Be Used

• Prior exposure to macrolide antibiotics (clarithromycin, azithromycin)
• Local clarithromycin resistance >15%
• Prior metronidazole use (if metronidazole-based triple)
• → Use quadruple therapy instead in these situations

Post-Treatment Verification

• Urea Breath Test (UBT) - preferred
• Stool antigen test
• Upper endoscopy with biopsy (if endoscopy done initially)

Quick Comparison: Triple vs. Quadruple

• Harrison's Principles of Internal Medicine 22E; Katzung 16th Ed.; KD Tripathi 7th Ed.