Two medicines, side by side
Tobramycin vs erythromycin
Tobramycin and erythromycin are both labeled for bacterial infections. Drugs@FDA records approvals of tobramycin since 1975 and of erythromycin since 1964. Pharmacies paid $1.08 per mL (Tobramycin 300 mg/5 mL ampule) and $1.96 per erythromycin 250 mg tablet (NADAC, October 7, 2026); the strengths differ, so the two prices are not like for like. In FDA's classes, tobramycin is an aminoglycoside antibacterial and erythromycin a macrolide.
Check it at the source: the tobramycin FDA label on DailyMed (effective November 1, 2023); the erythromycin FDA label on DailyMed (effective August 1, 2024).
Highlights of the tobramycin record
Tobramycin (Tobi) · label of November 1, 2023
Used for
From the label: indicationsTobramycin ophthalmic solution, 0.3% is a topical antibiotic indicated in the treatment of external infections of the eye and its adnexa caused by susceptible bacteria. Appropriate monitoring of bacterial response to topical antibiotic therapy should accompany the use of tobramycin ophthalmic solution. Clinical studies have shown tobramycin to be safe and effective for use in children.
On the market
- Earliest approval on file
- June 11, 1975
- Generic labelers
- 40 labelers
- Pharmacy cost
- $1.08 per mL
Supply and safety
- Shortage
- A presentation being discontinued
- Recalls
- 8
Highlights of the erythromycin record
Erythromycin (Erythrocin) · label of August 1, 2024
Used for
From the label: indicationsTo reduce the development of drug-resistant bacteria and maintain the effectiveness of erythromycin tablets and other antibacterial drugs, erythromycin tablets should be used only to treat or prevent infections that are proven or strongly suspected to be caused by susceptible bacteria. When culture and susceptibility information are available, they should be considered in selecting or modifying antibacterial therapy. […]
On the market
- Earliest approval on file
- June 25, 1964
- Generic labelers
- 38 labelers
- Pharmacy cost
- $1.96 per tablet
Supply and safety
- Shortage
- No current entry
- Recalls
- 2
Source: FDA drug labels via openFDA (Tobramycin label of November 1, 2023, Erythromycin label of August 1, 2024); NDC Directory, Drugs@FDA, NADAC, FDA shortages and recalls (October 8, 2026)
How do tobramycin and erythromycin differ on the record?
In FDA's classes, tobramycin is an aminoglycoside antibacterial and erythromycin a macrolide.
Generics: tobramycin since 1976; erythromycin since 1964 (Drugs@FDA).
| Tobramycin | Erythromycin | |
|---|---|---|
| Labeled for | Bacterial infections, Urinary tract infections | Bacterial infections, Acne |
| Pharmacologic class | Aminoglycoside Antibacterial | Macrolide, Macrolide Antimicrobial |
| How it works (label) | n/a | n/a |
| Half-life (label) | n/a | n/a |
| Earliest approval on file (Drugs@FDA) | June 11, 1975 | June 25, 1964 |
| First generic approved | October 1, 1976 | June 24, 1964 |
| Generic labelers (NDC) | 40 labelers | 38 labelers |
| Pharmacy cost (NADAC, each one's most listed form; strengths differ) | $1.08 per mL (Tobramycin 300 mg/5 mL ampule) | $1.96 per tablet (Erythromycin 250 mg tablet) |
| 12-month price change | -26% | +12% |
| Boxed warning | No | No |
| Shortage now | A presentation being discontinued | No current entry |
| Recalls recorded | 8 | 2 |
| FAERS reports (a report is not proof of cause; counts follow how widely a medicine is used) | 24,368 | 18,956 |
| 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 tobramycin
- every medicine labeled for the same conditions