Two medicines, side by side
Levofloxacin vs metronidazole
Levofloxacin and metronidazole are both labeled for bacterial infections. Drugs@FDA records approvals of levofloxacin since 1996 and of metronidazole since 1963. Pharmacies paid $0.259 per levofloxacin 750 mg tablet and $0.102 per metronidazole 250 mg tablet (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, levofloxacin is a fluoroquinolone antibacterial and metronidazole a nitroimidazole antimicrobial.
Check it at the source: the levofloxacin FDA label on DailyMed (effective July 10, 2024); the metronidazole FDA label on DailyMed (effective September 3, 2024).
Highlights of the levofloxacin record
Levofloxacin (Levaquin) · label of July 10, 2024
SERIOUS ADVERSE REACTIONS INCLUDING TENDINITIS, TENDON RUPTURE, PERIPHERAL NEUROPATHY, CENTRAL NERVOUS SYSTEM EFFECTS AND EXACERBATION OF MYASTHENIA GRAVIS See full prescribing information for complete boxed warning.
Used for
From the label: indicationsLevofloxacin is a fluoroquinolone antibacterial indicated in adults (18 years of age and older) with infections caused by designated, susceptible bacteria and in pediatric patients where indicated ( 1 , 12.4 ). […]
On the market
- Earliest approval on file
- December 20, 1996
- Generic labelers
- 44 labelers
- Pharmacy cost
- $0.259 per tablet
Supply and safety
- Shortage
- No current entry
- Recalls
- 13
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
Source: FDA drug labels via openFDA (Levofloxacin label of July 10, 2024, Metronidazole label of September 3, 2024); NDC Directory, Drugs@FDA, NADAC, FDA shortages and recalls (October 8, 2026)
How do levofloxacin and metronidazole differ on the record?
In FDA's classes, levofloxacin is a fluoroquinolone antibacterial and metronidazole a nitroimidazole antimicrobial.
Half-life, in each label's words: Levofloxacin, “The mean terminal plasma elimination half-life of levofloxacin ranges from approximately 6 to 8 hours following single …”; Metronidazole, “The elimination half-life, measured during the first 3 days of life, was inversely related to gestational age.”
Both labels carry a boxed warning; the records quote them.
Generics: levofloxacin since 2010; metronidazole since 1984 (Drugs@FDA).
| Levofloxacin | Metronidazole | |
|---|---|---|
| Labeled for | Bacterial infections, Urinary tract infections | Bacterial infections |
| Pharmacologic class | Fluoroquinolone Antibacterial | Nitroimidazole Antimicrobial |
| How it works (label) | Levofloxacin is a member of the fluoroquinolone class of antibacterial agents [see Microbiology ( 12.4 )]. | n/a |
| Half-life (label) | The mean terminal plasma elimination half-life of levofloxacin ranges from approximately 6 to 8 hours following single or multiple doses of levofloxacin given orally or intravenously. | The elimination half-life, measured during the first 3 days of life, was inversely related to gestational age. |
| Earliest approval on file (Drugs@FDA) | December 20, 1996 | July 18, 1963 |
| First generic approved | December 20, 2010 | December 6, 1984 |
| Generic labelers (NDC) | 44 labelers | 55 labelers |
| Pharmacy cost (NADAC, each one's most listed form; strengths differ) | $0.259 per tablet (Levofloxacin 750 mg tablet) | $0.102 per tablet (Metronidazole 250 mg tablet) |
| 12-month price change | -11% | +10% |
| Boxed warning | Yes | Yes |
| Shortage now | No current entry | In shortage |
| Recalls recorded | 13 | 7 |
| FAERS reports (a report is not proof of cause; counts follow how widely a medicine is used) | 59,954 | 63,553 |
| 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 levofloxacin
- every medicine labeled for the same conditions