Pharm 101: Ciprofloxacin
Class
Fluoroquinolone antibiotic
Pharmacodynamics
- Synthetic fluorinated analogue of nalidixic acid
- Bactericidal
- Blocks bacterial DNA synthesis by inhibiting bacterial topoisomerase II (DNA gyrase) and IV
- Prevents normal transcription and replication
Pharmacokinetics
- PO or IV administration:
- PO 250-500mg BD
- IV 200-300mg BD
- Bioavailability 70%
- Widely distributed in body fluids and tissues
- 20-40% protein bound
- Elimination half-life 3-5 hours
- Renal excretion
- CYP inhibitor
Antimicrobial activity
- Excellent gram negative cover
- Campylobacter, haemophilus, enterobacter, neisseria
- Moderate gram positive cover
- Activity against:
- MSSA
- Mycoplasma and Chlamydiae
- Legionella and Mycobacterium
- Pseudomonas
- Anthrax
- Clinical uses:
- UTI
- Bacterial gastroenteritis
- Osteomyelitis
- Soft tissue, intra-abdominal, respiratory infections
- Anthrax (drug of choice for prophylaxis and treatment)
Adverse effects of fluoroquinolones
- Gastrointestinal disturbances (nausea/vomiting/diarrhoea)
- Rash
- Abnormal LFTs
- Photosensitivity
- Growing cartilage damage (not routinely recommended for < 18 yo or pregnancy)
- Tendonitis
Precautions/contraindications
- Dose adjustment in renal failure
- Pregnancy and < 18 year old
- Concurrent steroid use (risk of tendon rupture)
References
- Katzung BG. Basic and Clinical Pharmacology. 14e. 2018: 837-840
Pharmacology 101
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Adult/Paediatric Emergency Medicine Advanced Trainee in Melbourne, Australia. Special interests in diagnostic and procedural ultrasound, medical education, and ECG interpretation. Co-creator of the LITFL ECG Library. Twitter: @rob_buttner