What the FDA labels say about taking them together
Streptomycin and tobramycin
Streptomycin's FDA label of January 21, 2026 names tobramycin in its boxed warning section, and tobramycin's label names streptomycin too.
Check it at the source: the streptomycin FDA label on DailyMed (effective January 21, 2026, XGen Pharmaceuticals DJB, Inc.); the tobramycin FDA label on DailyMed (effective November 1, 2023, Bausch & Lomb Incorporated).
What does the streptomycin label say about tobramycin?
Streptomycin label, boxed warningTHE CONCURRENT OR SEQUENTIAL USE OF OTHER NEUROTOXIC AND/OR NEPHROTOXIC DRUGS WITH STREPTOMYCIN SULFATE, INCLUDING NEOMYCIN, KANAMYCIN, GENTAMICIN, CEPHALORIDINE, PAROMOMYCIN, VIOMYCIN, POLYMYXIN B, COLISTIN, TOBRAMYCIN AND CYCLOSPORINE SHOULD BE AVOIDED.
Source: FDA drug label (Streptomycin), XGen Pharmaceuticals DJB, Inc., effective January 21, 2026 (SPL set abd1f64e-4283-4370-aae8-3666316aa36e), via openFDA; the full label on DailyMed
What does the tobramycin label say about streptomycin?
Tobi label (Viatris Specialty LLC, November 15, 2025), warnings and precautionsAminoglycosides cross the placenta, and streptomycin has been associated with several reports of total, irreversible, bilateral congenital deafness in pediatric patients exposed in utero.
Source: FDA drug label (Tobi, NDA050753), Viatris Specialty LLC, effective November 15, 2025 (SPL set 6a3c3871-1d3a-44d6-8be3-526b30123ef7), via openFDA
Source: FDA drug label (Tobramycin), Bausch & Lomb Incorporated, effective November 1, 2023 (SPL set a5693ec9-d2f7-4d45-90b0-a113c54840d7), via openFDA; the full label on DailyMed
These are the labels' own sentences. PlainMeds does not grade interactions; a pharmacist or prescriber can say what they mean for one person's medicines.
Both medicines on the record
| Streptomycin | Tobramycin | |
|---|---|---|
| Labeled for | n/a | Bacterial infections, Urinary tract infections |
| Boxed warning | Yes | No |
| Pharmacy cost (NADAC) | n/a | $1.08 per mL 300 mg/5 mL ampule |
| Shortage now | No current entry | A presentation being discontinued |
Source: FDA NDC Directory, CMS NADAC of October 7, 2026 and the FDA Drug Shortage Database (FDA files October 8, 2026)
What next?
- Check more medicines together
- up to five at once