Two medicines, side by side
Clindamycin vs metronidazole
Clindamycin and metronidazole are both labeled for bacterial infections. Drugs@FDA records approvals of clindamycin since 1970 and of metronidazole since 1963. Pharmacies paid $0.137 per gram (Clindamycin ph 1% gel) 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, clindamycin is a lincosamide antibacterial and metronidazole a nitroimidazole antimicrobial.
Check it at the source: the clindamycin FDA label on DailyMed (effective March 10, 2026); the metronidazole FDA label on DailyMed (effective September 3, 2024).
Highlights of the clindamycin record
Clindamycin (Cleocin) · label of March 10, 2026
Clostridioides difficile -associated diarrhea (CDAD) has been reported with use of nearly all antibacterial agents, including clindamycin hydrochloride and may range in severity from mild diarrhea to fatal colitis. Treatment with antibacterial agents alters the normal flora of the colon, leading to overgrowth of C. difficile.
Used for
From the label: indicationsClindamycin is indicated in the treatment of serious infections caused by susceptible anaerobic bacteria. Clindamycin is also indicated in the treatment of serious infections due to susceptible strains of streptococci, pneumococci, and staphylococci. Its use should be reserved for penicillin-allergic patients or other patients for whom, in the judgment of the physician, a penicillin is inappropriate. […]
On the market
- Earliest approval on file
- February 22, 1970
- Generic labelers
- 60 labelers
- Pharmacy cost
- $0.137 per gram
Supply and safety
- Shortage
- In shortage
- Recalls
- 24
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 (Clindamycin label of March 10, 2026, Metronidazole label of September 3, 2024); NDC Directory, Drugs@FDA, NADAC, FDA shortages and recalls (October 8, 2026)
How do clindamycin and metronidazole differ on the record?
In FDA's classes, clindamycin is a lincosamide antibacterial and metronidazole a nitroimidazole antimicrobial.
Half-life, in each label's words: Clindamycin, “Excretion The average biological half-life is 2.4 hours.”; 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: clindamycin since 1982; metronidazole since 1984 (Drugs@FDA).
| Clindamycin | Metronidazole | |
|---|---|---|
| Labeled for | Bacterial infections, Acne | Bacterial infections |
| Pharmacologic class | Lincosamide Antibacterial | Nitroimidazole Antimicrobial |
| How it works (label) | n/a | n/a |
| Half-life (label) | Excretion The average biological half-life is 2.4 hours. | The elimination half-life, measured during the first 3 days of life, was inversely related to gestational age. |
| Earliest approval on file (Drugs@FDA) | February 22, 1970 | July 18, 1963 |
| First generic approved | February 8, 1982 | December 6, 1984 |
| Generic labelers (NDC) | 60 labelers | 55 labelers |
| Pharmacy cost (NADAC, each one's most listed form; strengths differ) | $0.137 per gram (Clindamycin ph 1% gel) | $0.102 per tablet (Metronidazole 250 mg tablet) |
| 12-month price change | -10% | +10% |
| Boxed warning | Yes | Yes |
| Shortage now | In shortage | In shortage |
| Recalls recorded | 24 | 7 |
| FAERS reports (a report is not proof of cause; counts follow how widely a medicine is used) | 8,968 | 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 clindamycin
- every medicine labeled for the same conditions