Drug Guide
Amoxicillin; Clarithromycin; Vonoprazan Fumarate
Classification
Therapeutic: Antibacterial, Antiulcer Agent
Pharmacological: Beta-lactam Antibiotic, Macrolide, Potassium-Competitive Acid Blocker
FDA Approved Indications
- Helicobacter pylori eradication in peptic ulcer disease
Mechanism of Action
Amoxicillin inhibits bacterial cell wall synthesis; Clarithromycin inhibits bacterial protein synthesis by binding to the 50S ribosomal subunit; Vonoprazan blocks gastric acid secretion by inhibiting the H+/K+ ATPase enzyme in parietal cells.
Dosage and Administration
Adult: Typically, a 14-day course combining these agents as prescribed by the healthcare provider.
Pediatric: Use based on weight and medical condition, under supervision.
Geriatric: Adjustments may be necessary based on renal function.
Renal Impairment: Assess renal function; dosage adjustments may be required.
Hepatic Impairment: Monitor closely; adjust dose if necessary.
Pharmacokinetics
Absorption: Well absorbed orally.
Distribution: Widely distributed, including into gastric tissue.
Metabolism: Amoxicillin minimally metabolized; clarithromycin metabolized in the liver; vonoprazan rapidly absorbed and metabolized.
Excretion: Renally excreted for amoxicillin; hepatic metabolism for clarithromycin; renally and hepatically for vonoprazan.
Half Life: Amoxicillin: ~1 hour; clarithromycin: 3-7 hours; vonoprazan: ~7 hours.
Contraindications
- Allergy to penicillins, macrolides, or vonoprazan.
Precautions
- History of Clostridium difficile infection, severe hepatic or renal impairment.
- Pregnancy category B; consult with provider for use during lactation.
Adverse Reactions - Common
- Diarrhea (Common)
- Nausea (Common)
- Headache (Common)
Adverse Reactions - Serious
- Anaphylaxis (Rare)
- Clostridium difficile-associated diarrhea (Rare)
- Hepatotoxicity (Rare)
Drug-Drug Interactions
- Warfarin (altered INR), other CYP3A4 inhibitors/inducers affecting clarithromycin and vonoprazan
Drug-Food Interactions
- Avoid alcohol, which may increase gastrointestinal side effects.
Drug-Herb Interactions
- St. John’s Wort may decrease effectiveness of clarithromycin and vonoprazan.
Nursing Implications
Assessment: Monitor for allergic reactions, gastrointestinal symptoms, and signs of infection.
Diagnoses:
- Risk for allergic reaction
- Impaired comfort related to gastrointestinal disturbances.
Implementation: Administer with food if tolerated; monitor liver and kidney function as needed.
Evaluation: Assess eradication success with follow-up testing, monitor for adverse effects.
Patient/Family Teaching
- Complete full course of therapy.
- Report severe diarrhea or allergic reactions immediately.
- Take medications at scheduled times and as directed.
Special Considerations
Black Box Warnings:
- Clostridium difficile-associated diarrhea with antibiotics.
- Potential for QT prolongation (clarithromycin).
Genetic Factors: Consider CYP3A4 interactions affecting clarithromycin and vonoprazan metabolism.
Lab Test Interference: May alter liver function tests; monitor accordingly.
Overdose Management
Signs/Symptoms: Gastrointestinal distress, altered mental status, allergic reactions.
Treatment: Supportive care; activated charcoal if ingestion recent; manage symptoms; consult poison control.
Storage and Handling
Storage: Store at room temperature, away from moisture and light.
Stability: Stable as per manufacturer specifications.