Ciprofloxacin

1. Introduction

Ciprofloxacin, marketed under brand names such as Cipro and Ciloxan, is a broad-spectrum fluoroquinolone antibiotic. It is used to treat a variety of bacterial infections, including respiratory, urinary, gastrointestinal, and skin infections. It works by inhibiting bacterial DNA gyrase and topoisomerase IV, thereby preventing DNA replication and leading to bacterial cell death.

2. Indications

  • Approved Indications:
    • Urinary tract infections (UTIs), including pyelonephritis.
    • Respiratory tract infections, including pneumonia and bronchitis.
    • Skin and soft tissue infections.
    • Bone and joint infections.
    • Gastrointestinal infections, including traveller’s diarrhoea.
    • Prostatitis.
    • Typhoid fever.
    • Inhalational anthrax (post-exposure).
    • Gonorrhoea (uncomplicated).
  • Off-Label Uses:
    • Multidrug-resistant tuberculosis (part of combination therapy).
    • Post-surgical prophylaxis in high-risk cases.

3. Dosage

  • Adults:
    • Urinary tract infections: 250–500 mg orally every 12 hours, or 200–400 mg IV every 12 hours.
    • Respiratory infections: 500–750 mg orally every 12 hours, or 400 mg IV every 12 hours.
    • Skin and soft tissue infections: 500–750 mg orally every 12 hours, or 400 mg IV every 12 hours.
    • Typhoid fever: 500 mg orally every 12 hours for 10–14 days.
    • Inhalational anthrax: 500 mg orally every 12 hours or 400 mg IV every 12 hours for 60 days.
  • Children (only for specific indications such as inhalational anthrax or complicated UTIs):
    • 10–20 mg/kg orally every 12 hours (maximum 750 mg per dose).
    • 6–10 mg/kg IV every 8–12 hours (maximum 400 mg per dose).

4. Administration

  • Oral tablets can be taken with or without food, but avoid dairy products or calcium-fortified foods as they can reduce absorption.
  • Ensure adequate hydration during therapy to prevent crystalluria.
  • IV infusion should be administered over 60 minutes.

5. Forms Available

  • Tablets: 250 mg, 500 mg, 750 mg.
  • Extended-release tablets: 500 mg, 1000 mg.
  • IV solution: 200 mg/100 mL, 400 mg/200 mL.
  • Ophthalmic solution: 0.3%.
  • Otic solution: 0.2%.

6. Side Effects

6.1. Common Side Effects

  • Nausea.
  • Diarrhoea.
  • Abdominal pain.
  • Dizziness or headache.

6.2. Less Common Side Effects

  • Rash or photosensitivity.
  • Elevated liver enzymes.

6.3. Rare but Serious Side Effects

  • Tendinitis and tendon rupture.
  • QT prolongation and arrhythmias.
  • Peripheral neuropathy.
  • Clostridioides difficile-associated diarrhoea.
  • CNS effects (e.g., confusion, seizures).

7. Warnings

  • Increased risk of tendinitis and tendon rupture, particularly in older adults and those on corticosteroids.
  • Can exacerbate muscle weakness in patients with myasthenia gravis.
  • Prolonged use may result in superinfections, including fungal overgrowth or resistant bacteria.

8. Precautions

  • Avoid exposure to sunlight or tanning beds, as ciprofloxacin increases photosensitivity.
  • Use cautiously in patients with a history of seizures or CNS disorders.
  • Ensure proper hydration to reduce the risk of crystalluria.

9. Interactions

  • Drug-Drug Interactions:
    • Antacids, iron, and calcium supplements: Reduce ciprofloxacin absorption.
    • Warfarin: May increase anticoagulant effects, raising bleeding risk.
    • Theophylline: Increased serum levels of theophylline, leading to toxicity.
    • QT-prolonging agents: Increased risk of arrhythmias (e.g., amiodarone, macrolides).
  • Drug-Food Interactions:
    • Avoid dairy products or calcium-enriched foods close to ciprofloxacin dosing.

10. Monitoring Parameters

  • Symptom resolution (e.g., fever, pain, infection symptoms).
  • Monitor renal function, particularly in elderly patients or those with pre-existing renal impairment.
  • Watch for signs of tendinitis, CNS side effects, or QT prolongation in high-risk patients.

11. Use in Children

  • Use is generally limited to severe infections, such as complicated UTIs or inhalational anthrax.
  • Monitor closely for adverse effects, particularly joint or tendon problems.

12. Use in Pregnancy

  • Category C: Use only if the potential benefits outweigh the risks.
  • Avoid unless absolutely necessary due to concerns about cartilage development in the foetus.

13. Use in Elderly

  • Use with caution due to increased risk of tendon rupture, CNS effects, and QT prolongation.

14. Use in Kidney Disease

  • Dose adjustment is required in renal impairment.
    • CrCl 30–50 mL/min: Reduce dose by 50%.
    • CrCl <30 mL/min: Reduce dose or extend dosing interval.

15. Use in Liver Disease

  • No dose adjustment needed in mild to moderate hepatic impairment.
  • Use cautiously in severe liver disease.

16. Patient Counselling Points

  • Take the medication as prescribed, even if symptoms improve early.
  • Avoid antacids, calcium supplements, or dairy products close to dosing times.
  • Protect your skin from sunlight and use sunscreen to avoid photosensitivity.
  • Seek medical attention if you experience tendon pain, joint swelling, or CNS symptoms like confusion or seizures.
  • Maintain adequate hydration to prevent kidney-related side effects.

17. Table of Brand Names, Manufacturers, and Prices

Brand NameManufacturerPrice (USD)
CiproBayer$20–30 (30 tablets, 500 mg)
Ciloxan (ophthalmic)Alcon$10–15 (5 mL, 0.3%)
Generic OptionsVarious$10–20 (30 tablets, 500 mg)

18. FAQs (15 Questions)

  1. What is ciprofloxacin used for?
    It is used to treat bacterial infections, including UTIs, respiratory infections, and skin infections.
  2. How does ciprofloxacin work?
    It inhibits bacterial DNA replication by targeting DNA gyrase and topoisomerase IV.
  3. Can ciprofloxacin treat viral infections?
    No, ciprofloxacin is ineffective against viral infections like the common cold or flu.
  4. What are the common side effects of ciprofloxacin?
    Nausea, diarrhoea, abdominal pain, and dizziness.
  5. Is ciprofloxacin safe for children?
    It is generally reserved for severe infections in children due to potential joint and tendon issues.
  6. Can ciprofloxacin be taken during pregnancy?
    It should only be used if the benefits outweigh the risks, as it may affect cartilage development in the foetus.
  7. How should ciprofloxacin be taken?
    Take orally with or without food, but avoid dairy products or antacids around the dosing time.
  8. What should I avoid while taking ciprofloxacin?
    Avoid sun exposure, antacids, calcium-rich foods, and alcohol.
  9. Can ciprofloxacin cause tendon problems?
    Yes, it can cause tendinitis or tendon rupture, especially in older adults or those on corticosteroids.
  10. How long does ciprofloxacin take to work?
    Symptom improvement is typically seen within 2–3 days, but the full course must be completed.
  11. Does ciprofloxacin interact with other medications?
    Yes, it interacts with warfarin, theophylline, antacids, and QT-prolonging agents.
  12. How should ciprofloxacin eye drops be used?
    Apply 1–2 drops to the affected eye every 2 hours for the first 2 days, then reduce frequency as symptoms improve.
  13. Is ciprofloxacin available over the counter?
    No, it requires a prescription.
  14. Can ciprofloxacin cause diarrhoea?
    Yes, including severe diarrhoea due to C. difficile infection in rare cases.
  15. How should ciprofloxacin be stored?
    Store at room temperature, away from moisture and heat. Keep eye drops refrigerated after opening.