Makindo Medical Notes

⚠️ Important safety: Fluoroquinolones (including ciprofloxacin) carry risks of tendon rupture, neuropsychiatric effects, QT prolongation, and (rarely) aortic aneurysm/dissection. Use is restricted in UK practice — reserve for situations where other agents are inappropriate.

📖 About

• Ciprofloxacin is a fluoroquinolone antibiotic with broad Gram-negative activity, including Pseudomonas aeruginosa.
• Inhibits cytochrome P450 (CYP1A2), leading to multiple drug interactions.
• Well absorbed orally; widely distributed; primarily excreted renally.
• Always check the BNF for the latest guidance.

⚙️ Mode of Action

• Bactericidal: inhibits DNA gyrase (topoisomerase II) and topoisomerase IV.
• This prevents DNA replication, transcription, and repair in bacteria.

🦠 Activity Spectrum

• Gram negatives: E. coli, Klebsiella, Enterobacter, Salmonella, Shigella, Neisseria, Campylobacter, Haemophilus, Pseudomonas.
• Gram positives: limited (Staphylococcus aureus, Enterococcus faecalis); poor pneumococcal activity (not reliable for community pneumonia).
• Atypicals: some activity against Chlamydia and Mycoplasma, but not first-line.

🩺 Indications & Dose (BNF – check locally)

• Severe Gram-negative infections including Pseudomonas (esp. in cystic fibrosis).
• Complicated UTI / prostatitis.
• Typhoid and paratyphoid fever.
• Traveller’s diarrhoea.
• Anthrax (inhalation exposure).
• Gonorrhoea (not reliable due to resistance).
• Typical doses:
  • Oral: 500–750 mg every 12 hours.
  • IV: 400 mg every 12 hours, infused over 30–60 minutes.

🚫 Contraindications

• History of tendon disorders with fluoroquinolone use.
• Pregnancy and breastfeeding (avoid unless essential).
• Children and adolescents (avoid except in cystic fibrosis or life-threatening infections).
• Concomitant use with tizanidine (contraindicated – risk of severe hypotension).

⚠️ Cautions

• Epilepsy or CNS disorders (lowers seizure threshold).
• History of psychiatric illness (risk of agitation, psychosis).
• Myasthenia gravis (may exacerbate weakness).
• Cardiac disease / electrolyte abnormalities (risk of QT prolongation).
• Concurrent corticosteroid use (↑ risk of tendon rupture).

❗ Side Effects

• GI upset: nausea, vomiting, diarrhoea.
• CNS: insomnia, dizziness, confusion, hallucinations, seizures.
• Musculoskeletal: tendonitis, tendon rupture (esp. Achilles).
• CVS: QT prolongation, arrhythmias, rare aortic aneurysm/dissection.
• Hepatic: hepatitis, abnormal LFTs.
• Photosensitivity.

🔄 Interactions

• Warfarin: potentiates anticoagulant effect → ↑ INR.
• Theophylline: ↑ risk of toxicity (CYP1A2 inhibition).
• Caffeine: reduced clearance → ↑ stimulant effects.
• Antacids / iron / calcium: reduce ciprofloxacin absorption (separate by ≥2 hrs).
• Probenecid: reduces renal excretion of ciprofloxacin.
• Tizanidine: contraindicated (severe hypotension, sedation).

📚 References

• Summary of Product Characteristics
• MHRA Drug Safety Update (2019)