Two medicines, side by side
Metronidazole vs ciprofloxacin
Metronidazole and ciprofloxacin are both labeled for bacterial infections. Drugs@FDA records approvals of metronidazole since 1963 and of ciprofloxacin since 1987. Pharmacies paid $0.102 per metronidazole 250 mg tablet and $0.123 per ciprofloxacin HCl 500 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). Ciprofloxacin's other strengths are brand-only: $1.25 per mL (Cipro 5% suspension). In FDA's classes, metronidazole is a nitroimidazole antimicrobial and ciprofloxacin a fluoroquinolone antibacterial.
Check it at the source: the metronidazole FDA label on DailyMed (effective September 3, 2024); the ciprofloxacin FDA label on DailyMed (effective March 2, 2026).
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 ciprofloxacin record
Ciprofloxacin (Cipro) · label of March 2, 2026
SERIOUS ADVERSE REACTIONS INCLUDING TENDINITIS, TENDON RUPTURE, PERIPHERAL NEUROPATHY, CENTRAL NERVOUS SYSTEM EFFECTS AND EXACERBATION OF MYASTHENIA GRAVIS
Fluoroquinolones, including CIPRO ® , have been associated with disabling and potentially irreversible serious adverse reactions that have occurred together [see Warnings and Precautions ( 5.1 )], including:
Tendinitis and tendon rupture [see Warnings and Precautions ( 5.2 )].
Peripheral neuropathy [see Warnings and Precautions ( 5.3 )].
Used for
From the label: indicationsCIPRO is a fluoroquinolone antibacterial indicated in adults (18 years of age and older) with the following infections caused by designated, susceptible bacteria and in pediatric patients where indicated: • Skin and Skin Structure Infections ( 1.1 ) • Bone and Joint Infections ( 1.2 ) • Complicated Intra-Abdominal Infections ( 1.3 ) • Infectious Diarrhea ( 1.4 ) • Typhoid Fever (Enteric Fever) ( 1.5 ) • […]
On the market
- Earliest approval on file
- October 22, 1987
- Generic labelers
- 54 labelers
- Pharmacy cost
- $0.123 per tablet
Supply and safety
- Shortage
- No current entry
- Recalls
- 14
Source: FDA drug labels via openFDA (Metronidazole label of September 3, 2024, Ciprofloxacin label of March 2, 2026); NDC Directory, Drugs@FDA, NADAC, FDA shortages and recalls (October 8, 2026)
How do metronidazole and ciprofloxacin differ on the record?
In FDA's classes, metronidazole is a nitroimidazole antimicrobial and ciprofloxacin a fluoroquinolone 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.”; Ciprofloxacin, “The serum elimination half-life in subjects with normal renal function is approximately 4 hours.”
Both labels carry a boxed warning; the records quote them.
Generics: metronidazole since 1984; ciprofloxacin since 2004 (Drugs@FDA).
| Metronidazole | Ciprofloxacin | |
|---|---|---|
| Labeled for | Bacterial infections | Diarrhea, Urinary tract infections, Bacterial infections |
| Pharmacologic class | Nitroimidazole Antimicrobial | Fluoroquinolone Antibacterial, Quinolone Antimicrobial |
| How it works (label) | n/a | Ciprofloxacin is a member of the fluoroquinolone class of antibacterial agents [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 serum elimination half-life in subjects with normal renal function is approximately 4 hours. |
| Earliest approval on file (Drugs@FDA) | July 18, 1963 | October 22, 1987 |
| First generic approved | December 6, 1984 | March 16, 2004 |
| Generic labelers (NDC) | 55 labelers | 54 labelers |
| Pharmacy cost (NADAC, each one's most listed form; strengths differ) | $0.102 per tablet (Metronidazole 250 mg tablet) | $0.123 per tablet (Ciprofloxacin HCl 500 mg tablet) |
| 12-month price change | +10% | -9% |
| Boxed warning | Yes | Yes |
| Shortage now | In shortage | No current entry |
| Recalls recorded | 7 | 14 |
| FAERS reports (a report is not proof of cause; counts follow how widely a medicine is used) | 63,553 | 96,726 |
| 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