Dicloxacillin and Neomycin interaction
Dicloxacillin and Neomycin: both prescribing labels flag this combination with the strongest language, such as a contraindication, a boxed warning, or an instruction to avoid it.
Do not combine without a prescriber's guidance. The label language below is the strongest FDA uses.
What the FDA labels say
From the Dicloxacillin (DICLOXACILLIN SODIUM) label · effective 2026-08-13
In vitro mixing of penicillins and aminoglycosides should be avoided during concomitant therapy and the drugs should be administered separately.
Penicillins can inactivate aminoglycosides in vitro in serum samples from patients receiving both drugs, which could produce falsely decreased results in serum aminoglycoside assays of the serum samples.
Penicillinase-resistant penicillins, like other penicillins, are physically and/or chemically incompatible with aminoglycosides and can inactivate the drugs in vitro.
From the Neomycin (Neomycin Sulfate) label · effective 2026-04-24
Oral neomycin inhibits the gastrointestinal absorption of penicillin V, oral vitamin B-12, methotrexate and 5-fluorouracil.
Taking more than these two? Interactions stack. Check your whole list at once; it stays in your browser.
Open in the checkerNot medical advice. Interaction Checker quotes FDA label text and NIH fact sheets. Whether an interaction matters for you depends on doses, timing, kidney and liver function, and other conditions. Confirm with a pharmacist or prescriber.