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amoxicillin vs lansoprazole

Side-by-side comparison of amoxicillin and lansoprazole. Data from FDA drug databases (Orange Book, NDC Directory, recalls, shortages) covering 20,000+ approved drugs, plus CMS pricing; see our methodology.

major Known Drug Interaction

Combination Therapy with Clarithromycin and Amoxicillin Clinical Impact: Concomitant administration of clarithromycin with other drugs can lead to serious adverse reactions, including potentially fatal arrhythmias, and are contraindicated. Amoxicillin also has drug interactions. See Drug Interactions in prescribing information for amoxicillin.

Recommendation: Check with your doctor to make sure this combination is safe with your other medications.

Drug Class
amoxicillin Penicillin Antibiotic
lansoprazole Proton Pump Inhibitor (PPI)
Type
amoxicillin Prescription
lansoprazole Over-the-Counter
Summary
amoxicillin

Amoxicillin and Clavulanate Potassium is a combination medicine used to fight bacterial infections. It contains amoxicillin, an antibiotic, and clavulanate, which helps the amoxicillin work better.

lansoprazole

Lansoprazole is a medicine that reduces the amount of acid in your stomach. It belongs to a class of drugs called proton pump inhibitors (PPIs).

What It Treats
amoxicillin

This medicine treats infections like lower respiratory infections, ear infections (otitis media), sinus infections, skin infections, and urinary tract infections. It works against specific bacteria that cause these infections. However, it should only be used when tests show the bacteria are susceptible to it, to avoid antibiotic resistance.

lansoprazole

Lansoprazole can treat several conditions caused by too much stomach acid. It can heal duodenal and gastric ulcers. It also treats heartburn (GERD) and a damaged esophagus (erosive esophagitis).

How It Works
amoxicillin

Amoxicillin kills bacteria by stopping them from building cell walls. Some bacteria produce a substance called beta-lactamase, which can destroy amoxicillin. Clavulanate blocks beta-lactamase, allowing amoxicillin to effectively kill the bacteria.

lansoprazole

Lansoprazole works by blocking the enzyme in the stomach that produces acid. This helps to lower the amount of acid made. Lowering acid helps to heal damage and relieve symptoms.

Common Side Effects
amoxicillin
  • Diarrhea or loose stools
  • Nausea
  • Skin rashes
  • Hives
  • Vomiting
lansoprazole
  • Diarrhea
  • Abdominal pain
  • Nausea
  • Constipation
FAERS Reports
amoxicillin
  • Long-term kidney disease 4,661
  • Sudden kidney damage 4,200
  • Diarrhea 4,083
  • Allergic reaction to the medicine 3,744
  • Feeling sick to your stomach 3,700
lansoprazole
  • Long-term kidney disease 32,775
  • Sudden kidney damage 18,670
  • Kidney failure 13,811
  • Kidney failure requiring dialysis 9,782
  • Kidney damage 9,520
Serious Warnings
amoxicillin

This medicine can cause serious allergic reactions, including fatal ones. Stop taking it and get medical help right away if you have any signs of an allergic reaction. This medicine can also cause severe skin reactions. Tell your doctor if you develop a rash. It can also cause liver problems and severe diarrhea.

lansoprazole

Lansoprazole may hide the symptoms of stomach cancer. If you have a poor response or early return of symptoms, your doctor may do more tests. Long-term use of PPIs like lansoprazole may increase your risk of bone fractures. It may also cause low magnesium levels or Vitamin B-12 deficiency.

Pregnancy
amoxicillin

Tell your doctor if you are pregnant or plan to become pregnant. It is not known if this medicine will harm your unborn baby. Amoxicillin passes into breast milk and may cause harm to a nursing infant. Talk to your doctor before breastfeeding.

lansoprazole

Talk to your doctor if you are pregnant or plan to become pregnant. Lansoprazole may affect bone development in the fetus. If you take lansoprazole with clarithromycin, also consider clarithromycin's pregnancy risks.

Also Compare, Nearby Drugs

How to Read This amoxicillin vs lansoprazole Comparison

amoxicillin is classified in the Penicillin Antibiotic drug class, while lansoprazole sits within the Proton Pump Inhibitor (PPI) class. Drugs from different classes work through distinct mechanisms, so a head-to-head comparison illustrates trade-offs rather than equivalence. Both drugs are split between OTC and prescription status, which affects access and supervision.

Adverse event totals above are pulled from the FDA's Adverse Event Reporting System (FAERS). For these top-ranked reactions alone, amoxicillin has 20,388 submissions while lansoprazole has 84,558. Those figures reflect cumulative reporting volume, not per-patient risk, so older, widely dispensed drugs typically look worse on count alone. These two drugs have a known major interaction flagged in FDA labeling, attributed to using these drugs together as part of a treatment plan can increase the risk of side effects or change how other medicines work.. Serious warnings, pregnancy guidance, and contraindications can differ even when indications overlap.

A table cannot substitute for clinical judgment. Effectiveness, tolerability, drug-drug interactions with your other medications, kidney and liver function, pregnancy status, insurance formulary, and price all feed into a decision that only a licensed prescriber can make responsibly. Data here is sourced from FDA Structured Product Labels (SPL) and FAERS, both of which update as manufacturers and clinicians submit new information. This page is for educational purposes only, is not medical advice, and should not be used to self-switch between amoxicillin and lansoprazole - always consult your physician or pharmacist first.

Important: This comparison is for informational purposes only. Drug effects vary between individuals. Always consult your doctor or pharmacist for personalized medical advice.