Two medicines, side by side
Allopurinol vs amoxicillin/clavulanate
Allopurinol is labeled for gout; amoxicillin/clavulanate for urinary tract infections and bacterial infections. Their labels share no use, so they are not alternatives to each other. Drugs@FDA records approvals of allopurinol since 1966 and of amoxicillin/clavulanate since 1984. Pharmacies paid $0.0315 per allopurinol 100 mg tablet and $0.0693 per mL (Amox-clav 600-42.9 mg/5 mL sus) (NADAC, October 7, 2026); the strengths differ, so the two prices are not like for like. In FDA's classes, allopurinol is a xanthine oxidase inhibitor and amoxicillin/clavulanate a beta lactamase inhibitor.
Check it at the source: the allopurinol FDA label on DailyMed (effective May 21, 2026); the amoxicillin/clavulanate FDA label on DailyMed (effective May 1, 2025).
Highlights of the allopurinol record
Allopurinol (Zyloprim) · label of May 21, 2026
Used for
From the label: indicationsAllopurinol tablet is indicated for: The management of adults with signs and symptoms of primary or secondary gout (acute attacks, tophi, joint destruction, uric acid lithiasis, and/or nephropathy) The management of adult and pediatric patients with leukemia, lymphoma and solid tumor malignancies who are receiving cancer therapy which causes elevations of serum and urinary uric acid levels The management of adult […]
On the market
- Earliest approval on file
- August 19, 1966
- Generic labelers
- 44 labelers
- Pharmacy cost
- $0.0315 per tablet
Supply and safety
- Shortage
- A presentation being discontinued
- Recalls
- 6
Highlights of the amoxicillin and clavulanate record
Amoxicillin and clavulanate (Augmentin) · label of May 1, 2025
Used for
From the label: indicationsAmoxicillin and clavulanate potassium is indicated for the treatment of infections in adults and pediatric patients, due to susceptible isolates of the designated bacteria in the conditions listed below: • Lower Respiratory Tract Infections - caused by beta‑lactamase‑producing isolates of Haemophilus influenzae and Moraxella catarrhalis. […]
On the market
- Earliest approval on file
- August 6, 1984
- Generic labelers
- 31 labelers
- Pharmacy cost
- $0.0693 per mL
Supply and safety
- Shortage
- No current entry
- Recalls
- 5
Source: FDA drug labels via openFDA (Allopurinol label of May 21, 2026, Amoxicillin/clavulanate label of May 1, 2025); NDC Directory, Drugs@FDA, NADAC, FDA shortages and recalls (October 8, 2026)
How do allopurinol and amoxicillin/clavulanate differ on the record?
In FDA's classes, allopurinol is a xanthine oxidase inhibitor and amoxicillin/clavulanate a beta lactamase inhibitor.
How each works, in its label's words: Allopurinol, “Allopurinol is a structural analogue of the natural purine base, hypoxanthine.”; Amoxicillin/clavulanate, “Amoxicillin and clavulanate potassium is an antibacterial drug [see Microbiology ( 12.4 )].”
Half-life, in each label's words: Allopurinol, “Elimination The half-life of allopurinol and oxipurinol are approximately 1 hour to 2 hours and 15 hours following oral …”; Amoxicillin/clavulanate, “Metabolism and Excretion The half-life of amoxicillin after the oral administration of amoxicillin and clavulanate …”
Generics: allopurinol since 1985; amoxicillin/clavulanate since 2002 (Drugs@FDA).
| Allopurinol | Amoxicillin/clavulanate | |
|---|---|---|
| Labeled for | Gout | Urinary tract infections, Bacterial infections |
| Pharmacologic class | Xanthine Oxidase Inhibitor | Penicillin-class Antibacterial, beta Lactamase Inhibitor |
| How it works (label) | Allopurinol is a structural analogue of the natural purine base, hypoxanthine. Allopurinol acts on purine catabolism, without disrupting the biosynthesis of purines. | Amoxicillin and clavulanate potassium is an antibacterial drug [see Microbiology ( 12.4 )]. |
| Half-life (label) | Elimination The half-life of allopurinol and oxipurinol are approximately 1 hour to 2 hours and 15 hours following oral dose of allopurinol, respectively. | Metabolism and Excretion The half-life of amoxicillin after the oral administration of amoxicillin and clavulanate potassium is 1.3 hours and that of clavulanic acid is 1 hour. |
| Earliest approval on file (Drugs@FDA) | August 19, 1966 | August 6, 1984 |
| First generic approved | December 10, 1985 | March 14, 2002 |
| Generic labelers (NDC) | 44 labelers | 31 labelers |
| Pharmacy cost (NADAC, each one's most listed form; strengths differ) | $0.0315 per tablet (Allopurinol 100 mg tablet) | $0.0693 per mL (Amox-clav 600-42.9 mg/5 mL sus) |
| 12-month price change | -20% | +2% |
| Boxed warning | No | No |
| Shortage now | A presentation being discontinued | No current entry |
| Recalls recorded | 6 | 5 |
| FAERS reports (a report is not proof of cause; counts follow how widely a medicine is used) | 155,998 | 27,019 |
| DEA schedule | none | none |
Source: Drugs@FDA, FDA NDC Directory, CMS NADAC of October 7, 2026, FDA shortages and recalls, FAERS via openFDA (FDA files October 8, 2026)
Do their labels mention each other?
Amoxicillin/clavulanate label, drug interactionsCo-administration with allopurinol increases the risk of rash.
Amoxicillin/clavulanate label, drug interactionsDRUG INTERACTIONS Co-administration with probenecid is not recommended. (7.1) Concomitant use Amoxicillin and Clavulanate Potassium Extended Release Tablets and oral anticoagulants may increase the prolongation of prothrombin time. (7.2) Co-administration with allopurinol increases the risk of rash. (7.3) Amoxicillin and Clavulanate Potassium Extended Release Tablets may reduce efficacy of oral contraceptives.
Source: FDA drug labels via openFDA
What next?
- Alternatives to allopurinol
- every medicine labeled for the same conditions