Ciprofloxacin (hydrochloride monohydrate) is a fluoroquinolone antibiotic, exhibiting potent antibacterial activity. Ciprofloxacin (hydrochloride monohydrate) (CIP) shows potent activity against Y. pestis with MIC ₉₀ of 0.03 μg/mL.

Ciprofloxacin (hydrochloride monohydrate) (1 mg/L) induces glutathione-S-transferase (GST) activity, in contrast with inhibited GST and Catalase (CAT) of larvae exposed to enrofloxacin. Ciprofloxacin (hydrochloride monohydrate) (≥10 μg/L) is ecotoxic for development, growth, detoxifying, and oxidative stress enzymes in anuran amphibian larvae. In a murine model of pneumonic plague, Ciprofloxacin (hydrochloride monohydrate) (30 mg/kg, i.p.) results in a drug exposure which is similar to the drug exposure observed in human following a 500 mg dose of oral Ciprofloxacin (hydrochloride monohydrate). Intraperitoneal Ciprofloxacin (hydrochloride monohydrate) reduces the lung bacterial load compare to controls treated with intraperitoneal PBS.