Fluoroquinolones

Fluoroquinolones

Drug monograph · NCLEX study reference
Therapeutic class	Antibacterial
Pharmacologic class	Fluoroquinolone
Onset / peak / duration	Rapid; once or twice daily.
Half-life / level	Levofloxacin and moxifloxacin once daily; no routine level.
Routes	PO (oral), IV
High-alert (ISMP)	No
Black box warning	Yes (see Safety)
Antidote / reversal	Supportive care.
Pregnancy / lactation	Generally avoided.

Nursing pharmacology study reference (NCLEX-style monograph). Numeric values are standard teaching ranges for study and must be verified against current manufacturer labeling before clinical use. This is educational content, not prescribing guidance.

Fluoroquinolones — Antibacterial; Fluoroquinolone.

Identification

• Therapeutic class: Antibacterial.
• Pharmacologic class: Fluoroquinolone.

Pharmacology

• Mechanism of action: Inhibit DNA gyrase and topoisomerase IV to block DNA replication (bactericidal).
• Onset / peak / duration: Rapid; once or twice daily.
• Half-life / therapeutic level: Levofloxacin and moxifloxacin once daily; no routine level.

Clinical use

• Indications: Complicated urinary, respiratory, GI, and intra-abdominal infections; reserved when alternatives are unsuitable.
• Usual dose, route, frequency: PO or IV once or twice daily.
• Maximum dose / adjustments: Reduce cipro and levo in renal impairment; moxifloxacin not for urinary infections.

Safety

• Contraindications: Hypersensitivity; caution with myasthenia gravis, QT prolongation, tendon disorders.
• Black box warning: Risk of tendinitis and tendon rupture, peripheral neuropathy, central nervous system effects, and worsening of myasthenia gravis; reserve for situations with no alternative.
• Interactions: Antacids, iron, calcium, magnesium, and dairy reduce absorption (separate doses); warfarin, theophylline (cipro raises levels), QT-prolonging drugs, NSAIDs (CNS effects).
• Pregnancy / lactation: Generally avoided.
• High-alert: No.

Adverse effects

• Common side effects: Nausea, diarrhea, headache, dizziness, photosensitivity.
• Serious effects to report: Tendon pain or rupture, neuropathy (numbness, tingling), QT prolongation, hypoglycemia or hyperglycemia, C. difficile colitis, aortic aneurysm risk.
• Antidote / reversal: Supportive care.

Nursing process

• Assessment before administration: Allergy, tendon and neuro history, QT and cardiac risk, glucose in diabetics.
• Interventions during therapy: Hold and report tendon pain; separate from mineral binders; monitor glucose in diabetics.
• Monitor: Tendons, neuro status, glucose, ECG if at risk, infection resolution.
• Evaluation / expected outcome: Resolution of infection.

Patient teaching

• Patient teaching: Report tendon pain, numbness, or palpitations; avoid antacids and dairy near doses; use sun protection.
• Notify provider if: Tendon or joint pain or swelling, numbness or tingling, palpitations, chest or back pain.
• Administration tips: Separate from antacids, iron, calcium, and dairy by at least 2 hours.