What the FDA labels say about taking them together
Ertapenem and lidocaine
Ertapenem's FDA label of February 4, 2026 names lidocaine in its contraindications section; the lidocaine labels PlainMeds reads (4) do not name ertapenem. The ertapenem label: “Due to the use of lidocaine HCl as a diluent, INVANZ administered intramuscularly is contraindicated in patients with a known hypersensitivity to local anesthetics of the amide type.”
Check it at the source: the ertapenem FDA label on DailyMed (effective February 4, 2026, Merck Sharp & Dohme LLC); the lidocaine FDA label on DailyMed (effective May 13, 2024, Fresenius Kabi USA, LLC).
What does the ertapenem label say about lidocaine?
Ertapenem label, contraindicationsDue to the use of lidocaine HCl as a diluent, INVANZ administered intramuscularly is contraindicated in patients with a known hypersensitivity to local anesthetics of the amide type.
Source: FDA drug label (INVANZ), Merck Sharp & Dohme LLC, effective February 4, 2026 (SPL set 33f3b99b-fa82-42e0-26bf-f49891ae3d22), via openFDA; the full label on DailyMed
What does the lidocaine label say about ertapenem?
Lidocaine's label (effective May 13, 2024) and its 3 other brand-application labels do not name ertapenem in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (Xylocaine MPF), Fresenius Kabi USA, LLC, effective May 13, 2024 (SPL set d5e0d06f-ba1e-44d4-aa89-39d6c146dc23), 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
| Ertapenem | Lidocaine | |
|---|---|---|
| Labeled for | Urinary tract infections | Pain |
| Boxed warning | No | No |
| Pharmacy cost (NADAC) | $26.63 per vial 1 gram vial | $0.154 per gram 5% ointment |
| Shortage now | No current entry | In shortage |
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