acetylsalicylic acid × ciprofloxacin

Older experimental data suggested that NSAIDs combined with fluoroquinolones increase CNS excitability and seizure risk (via fluoroquinolone-mediated GABA-A receptor antagonism with possible NSAID potentiation). Clinically meaningful seizure frequency is rare but the risk is elevated in older patients, CKD, and prior epilepsy.

In patients without epilepsy and with normal eGFR, the combination is acceptable, particularly at antiplatelet aspirin doses. With prior epilepsy or eGFR below 30 mL/min, choose a non-fluoroquinolone.