3.10 Fluoroquinolones

Fluoroquinolones are broad-spectrum antibacterial medications that are commonly used to treat respiratory infections.

Mechanism of Action: Fluoroquinolones are a synthetic antibacterial medication that work by inhibiting the bacterial DNA replication. They are bactericidal due to the action they take against the DNA of the bacterial cell wall. Many fluoroquinolones are broad-spectrum and effective against a wide variety of both gram-positive and gram-negative bacteria.

Indications: Fluoroquinolones may be used to treat pneumonia or complicated skin or urinary tract infections.

Nursing Considerations: Clients taking oral fluoroquinolones should avoid the use of antacid medications because they significantly impede absorption. Clients should also be instructed to take oral fluoroquinolones with a full glass of water two hours before or after meals to enhance absorption and prevent crystalluria. Fluoroquinolone therapy is contraindicated in children except for complicated UTIs, pyelonephritis, plague, or post-anthrax exposure and should be used cautiously in pregnancy.[1]

Side Effects/Adverse Effects: Common side effects to monitor for include drowsiness and GI upset. Additional side effects to monitor for include hypersensitivity, photosensitivity, hypoglycemia, C-diff, and rash. Other adverse effects include fainting, decreased heart rate, prolonged QT syndrome, and mood changes.

Boxed Warning: Fluoroquinolones, including levofloxacin, have been associated with disabling and potentially irreversible serious adverse reactions, including the following:

  • Tendinitis and tendon rupture
  • Peripheral neuropathy
  • Central nervous system effects
  • Exacerbation of muscle weakness in clients with myasthenia gravis

In clients who experience any of these serious adverse reactions, discontinue the medication immediately, and avoid the use of fluoroquinolones.

Health Teaching & Health Promotion: All clients on fluoroquinolone therapy should be instructed to avoid direct and indirect sunlight due to the photosensitivity that can be experienced while on these medications. The client should take measures to ensure that dosages are spaced evenly throughout the day and that fluid balance is maintained. It is important to maintain an intake of 1,500 mL-2,000 mL per day while taking the medication. The client should be advised that medications containing calcium, aluminum, iron, or zinc may impair absorption and should not be taken within two hours of ingestion of the medication. Additionally, the client should be cautioned to monitor for episodes of fainting or decreased heart rate and report any history of prolonged QT syndrome. If a client notices peripheral neuropathy occurring, this should be reported to the health care provider. Additional side effects to monitor include increased tendon pain, jaundice, rash, or mood changes.[2]

Now let’s take a closer look at the medication grid for levofloxacin in Table 3.10.[3] 

Table 3.10 Fluoroquinolone Medication Grid

Class/Subclass
Prototype/Generic
Nursing Considerations
Therapeutic Effects
Side/Adverse Effects
Fluoroquinolones levofloxacin Check for allergies

Give with plenty of fluids

Oral: Administer 2 hours before or after meals, antacids, or iron

IV: Infuse 500 mg or less over 60 minutes and doses of 750 mg over 90 minutes

Dosage adjustment if renal or hepatic impairment

Use cautiously if history of seizures

Boxed Warning: Fluoroquinolones have been associated with disabling and potentially irreversible serious adverse reactions, including the following:

  • Tendinitis and tendon rupture
  • Peripheral neuropathy
  • Central nervous system effects
  • Exacerbation of muscle weakness in clients with myasthenia gravis
Monitor for systemic signs of infection:

-WBCs

-Fever

Monitor actual site of infection

Monitor culture results, if obtained

Drowsiness

Monitor for:

-GI upset

-Hypersensitivity

-Photosensitivity

-Hypoglycemia

-C-diff

-Fainting

-Decreased heart rate

-Prolonged QT syndrome

-Rash

-Mood changes

SAFETY: Discontinue immediately if tendonitis, tendon rupture, jaundice, peripheral neuropathy, CNS effects, or muscle weakness in clients with myasthenia gravis

Critical Thinking Activity 3.10Image of a circle containing a speech bubble with a question mark in it.

Using the above grid information, consider the following clinical scenario question:

A nurse is administering levofloxacin to a client diagnosed with pneumonia. The client reports they have pain “above the heel” today. The nurse assesses and discovers the pain is over the Achilles’ tendon. What is the nurse’s next best response?

Note: Answers to the Critical Thinking activities can be found in the “Answer Key” section at the end of the book.


  1. This work is a derivative of Microbiology by OpenStax licensed under CC BY 4.0. Access for free at https://openstax.org/books/microbiology/pages/1-introduction
  2. uCentral from Unbound Medicine. https://www.unboundmedicine.com/ucentral
  3. This work is a derivative of DailyMed by U.S. National Library of Medicine in the Public Domain.

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