Ciprofloxacin and Levofloxacin interaction
Ciprofloxacin and Levofloxacin: 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 Ciprofloxacin label · effective 2026-06-30
Click here to enter Contraindications Known hypersensitivity to ciprofloxacin or other quinolones ( 4.1 , 5.6, 5.7 )
Avoid use in patients with known prolongation, those with hypokalemia, and with other drugs that prolong the QT interval.
Ciprofloxacin, like other fluoroquinolones, is known to trigger seizures or lower the seizure threshold.
From the Levofloxacin label · effective 2024-05-22
Levofloxacin in 5% Dextrose Injection is contraindicated in persons with known hypersensitivity to levofloxacin, or other quinolone antibacterials [see Warnings and Precautions (5.3) ].
Known hypersensitivity to Levofloxacin in 5% Dextrose Injection or other quinolones ( 4 , 5.7 ).
Avoid use in patients with known prolongation, those with hypokalemia, and with other drugs that prolong the QT interval ( 5.11 , 8.5 )
As with other fluoroquinolones, Levofloxacin in 5% Dextrose Injection should be used with caution in patients with a known or suspected central nervous system (CNS) disorder that may predispose them to seizures or lower the seizure threshold (e.g., severe cerebral arteriosclerosis, epilepsy) or in the presence of other risk factors that may predispose them to…
However, concomitant administration of other fluoroquinolones with theophylline has resulted in prolonged elimination half-life, elevated serum theophylline levels, and a subsequent increase in the risk of theophylline-related adverse reactions in the patient population.
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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.