Diflunisal and Salsalate interaction
Diflunisal and Salsalate: 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 Diflunisal label · effective 2026-08-04
Diflunisal tablets should not be given to patients who have experienced asthma, urticaria, or allergic-type reactions after taking aspirin or other NSAIDs.
This symptom complex typically occurs in asthmatic patients who experience rhinitis with or without nasal polyps, or who exhibit severe, potentially fatal bronchospasm after taking aspirin or other NSAIDs (see CONTRAINDICATIONS and PRECAUTIONS, Preexisting Asthma ).
The concomitant use of diflunisal tablets and other NSAIDs is not recommended due to the increased possibility of gastrointestinal toxicity, with little or no increase in efficacy.
The clinical significance of this interaction is not known; however, as with other NSAIDs, concomitant administration of diflunisal tablets and aspirin is not generally recommended because of the potential of increased adverse effects.
Anaphylactic/Anaphylactoid Reactions As with other NSAIDs, anaphylactic/anaphylactoid reactions may occur in patients without known prior exposure to diflunisal tablets.
From the Salsalate label · effective 2024-02-08
Salsalate tablets, USP should not be given to patients who have experienced asthma, urticaria, or allergic-type reactions after taking aspirin or other NSAIDs.
This symptom complex typically occurs in asthmatic patients who experience rhinitis with or without nasal polyps, or who exhibit severe, potentially fatal bronchospasm after taking aspirin or other NSAIDs (see CONTRAINDICATIONS and PRECAUTIONS - Preexisting Asthma ).
ASPIRIN AND OTHER SALICYLATE DRUGS WILL BE ADDITIVE TO SALSALATE AND MAY INCREASE PLASMA CONCENTRATIONS OF SALICYLIC ACID TO TOXIC LEVELS.
The clinical significance of this interaction is not known; however,] as with other NSAIDs, concomitant administration of salsalate and aspirin is not generally recommended because of the potential of increased adverse effects.
Anaphylactoid Reactions As with other NSAIDs, anaphylactoid reactions may occur in patients without known prior exposure to Salsalate tablets, USP.
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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.