UMEM Educational Pearls


An 86 year-old nursing home resident presents to the ED with a urinary tract infection, four days after discharge from the inpatient service for the same diagnosis. She was discharged from the inpatient service with a prescription for ciprofloxacin to be given through her gastric feeding tube (she does not take anything orally). Could her tube feeds be playing a role in the relapse of her urinary tract infection?


Answer: Ciprofloxacin was not being properly absorbed secondary to enteral tube feeding.

Fluoroquinolones administered via enteral feeding tubes may have reduced efficacy and patient outcomes when given to patients simultaneously receiving tube feeds (e.g., PEG tube feeding).

The reduction in antimicrobial efficacy may be due to improper peak drug concentrations and variability in time to peak serum levels. Studies have demonstrated the bioavailability of Ciprofloxacin varies from 31-82% in patients receiving continuous enteral feeds.

The exact mechanism(s) responsible for the altered pharmokinetics are not completely understood but may involve the binding of divalent cations in the enteral feeds by fluoroquinolones, reducing its absorption and efficacy.

Clinicians should properly educate people who will be administering fluoroquinolones to the patient (e.g., nursing home staff, family, etc.). It is recommended that fluoroquinolones be given:

  • 2 hours before starting enteral feeds, or
  • 4 hours after enteral feeds have been held

Perhaps easiest of all, is to consider discharging patients with a prescription for parenterally administered antibiotics for the duration of the infection.


Beckwith MF, Feddema SS, Barton RG, Graves C. A guide to drug therapy in patients with enteral feeding tubes: Dosage form selection and administration methods. Hosp Pharm. 2004;39:225–37

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