Two medicines, side by side
Metronidazole vs vancomycin
Metronidazole and vancomycin are both labeled for bacterial infections. Drugs@FDA records approvals of metronidazole since 1963 and of vancomycin since 1986. Pharmacies paid $0.102 per metronidazole 250 mg tablet and $1.33 per vancomycin HCl 125 mg capsule (NADAC, October 7, 2026); the strengths differ, so the two prices are not like for like. Metronidazole's other strengths are brand-only: $2.60 per mL (Likmez 500 mg/5 mL suspension). In FDA's classes, metronidazole is a nitroimidazole antimicrobial and vancomycin a glycopeptide antibacterial.
Check it at the source: the metronidazole FDA label on DailyMed (effective September 3, 2024); the vancomycin FDA label on DailyMed (effective June 7, 2024).
Highlights of the metronidazole record
Metronidazole (Flagyl) · label of September 3, 2024
Metronidazole has been shown to be carcinogenic in mice and rats (see PRECAUTIONS ). Unnecessary use of the drug should be avoided. Its use should be reserved for the conditions described in the INDICATIONS AND USAGE section below.
Used for
From the label: indicationsSymptomatic Trichomoniasis. Metronidazole tablets are indicated for the treatment of T. vaginalis infection in females and males when the presence of the trichomonad has been confirmed by appropriate laboratory procedures (wet smears and/or cultures). Asymptomatic Trichomoniasis. […]
On the market
- Earliest approval on file
- July 18, 1963
- Generic labelers
- 55 labelers
- Pharmacy cost
- $0.102 per tablet
Supply and safety
- Shortage
- In shortage
- Recalls
- 7
Highlights of the vancomycin record
Vancomycin (Vancocin Hydrochloride) · label of June 7, 2024
Used for
From the label: indicationsVancomycin Hydrochloride for Injection is a glycopeptide antibacterial indicated in adult and pediatric patients (neonates and older) for the treatment of: • Septicemia ( 1.1 ) • Infective Endocarditis ( 1.2 ) • Skin and Skin Structure Infections ( 1.3 ) • Bone Infections ( 1.4 ) • Lower Respiratory Tract Infections ( 1.5 ) To reduce the development of drug-resistant bacteria and maintain the effectiveness of […]
On the market
- Earliest approval on file
- April 15, 1986
- Generic labelers
- 31 labelers
- Pharmacy cost
- $1.33 per capsule
Supply and safety
- Shortage
- A presentation being discontinued
- Recalls
- 49
Source: FDA drug labels via openFDA (Metronidazole label of September 3, 2024, Vancomycin label of June 7, 2024); NDC Directory, Drugs@FDA, NADAC, FDA shortages and recalls (October 8, 2026)
How do metronidazole and vancomycin differ on the record?
In FDA's classes, metronidazole is a nitroimidazole antimicrobial and vancomycin a glycopeptide antibacterial.
Half-life, in each label's words: Metronidazole, “The elimination half-life, measured during the first 3 days of life, was inversely related to gestational age.”; Vancomycin, “The mean elimination half-life of vancomycin from plasma is 4 to 6 hours in subjects with normal renal function.”
Only the metronidazole label carries a boxed warning.
Generics: metronidazole since 1984; vancomycin since 1964 (Drugs@FDA).
| Metronidazole | Vancomycin | |
|---|---|---|
| Labeled for | Bacterial infections | Bacterial infections, Diarrhea |
| Pharmacologic class | Nitroimidazole Antimicrobial | Glycopeptide Antibacterial |
| How it works (label) | n/a | Vancomycin is an antibacterial drug [see Microbiology (12.4) ]. |
| Half-life (label) | The elimination half-life, measured during the first 3 days of life, was inversely related to gestational age. | The mean elimination half-life of vancomycin from plasma is 4 to 6 hours in subjects with normal renal function. |
| Earliest approval on file (Drugs@FDA) | July 18, 1963 | April 15, 1986 |
| First generic approved | December 6, 1984 | November 6, 1964 |
| Generic labelers (NDC) | 55 labelers | 31 labelers |
| Pharmacy cost (NADAC, each one's most listed form; strengths differ) | $0.102 per tablet (Metronidazole 250 mg tablet) | $1.33 per capsule (Vancomycin HCl 125 mg capsule) |
| 12-month price change | +10% | +4% |
| Boxed warning | Yes | No |
| Shortage now | In shortage | A presentation being discontinued |
| Recalls recorded | 7 | 49 |
| FAERS reports (a report is not proof of cause; counts follow how widely a medicine is used) | 63,553 | 65,529 |
| 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)
What next?
- Alternatives to metronidazole
- every medicine labeled for the same conditions