Dr Sharon Rees @reesprescribe
Day 1: A by-product of chloroquine synthesis, quinolone antibiotics were discovered in the early 1960s. Already broad-spectrum, the addition of chemical groups such as fluorine led to the 2nd generation agents such as #ciprofloxacin, which have enhanced gram-ve action. Licensed in 1987.
Dr Sharon Rees @reesprescribe
Day 2: #ciprofloxacin adult uses: various respiratory tract infections, especially where gram-ve bacteria; upper UTIs; acute prostatitis; gonorrhoea; diabetic foot infection; gram-ve skin/bone infections; anthrax; surgical prophylaxis; fistulating Crohn's. NOTE: ineffective v Streptococcus spp. Children; severe respiratory and GI infections; complex UTI/pyelonephritis (not exhaustive). The usual adult oral dose range 500-750 mg twice daily, duration variable. i.v 400 mg every 12 hours given over 60 mins (not exhaustive). Formulations: tablet, suspension, infusion.
Dr Sharon Rees @reesprescribe
Day 3: #ciprofloxacin has good oral absorption and bioavailability. Avoid with dairy/calcium products 1-2 hours before or 4 hrs after as this reduces absorption. Low protein binding, high volume of distribution and high tissue drug concentrations. Some metabolism via CYP1A2, but majority undergoes renal excretion unchanged, t½ 4-7 hrs. #ciprofloxacin itself is a moderate inhibitor of CYP1A2, with relevance to drug-drug interactions.
Dr Sharon Rees @reesprescribe
Day 4: To fit in a double stranded DNA chromosome (longer than itself), bacterium ‘twist’ their DNA via ‘breaks’ and lock into place via DNA gyrase family, which also permit relaxation’ of key regions for reasons such as replication. Quinolones bind & cause chromosome cleavages, triggering cell death. Humans also express topoisomerase enzymes, but with minimal homology, allowing selective toxicity for the quinolone class #ciprofloxacin.
Dr Sharon Rees @reesprescribe
Day 5: #ciprofloxacin adverse drug reactions (some dose-related); common include nausea/diarrhoea. Uncommon are mycotic superinfections, agitation, sleep disturbance, rash, photosensitivity reactions. Rare; blood disorders, psychiatric reactions, SJS, tendon rupture (can occur months after). Can trigger seizures, for example if used with NSAIDs, and caution hypoglycaemia (especially in elderly) and caution if risk factors for QT prolongation. Rarely severe reactions with chronic fatigue, neuro/MSK symptoms; can be severe/disabling/irreversible (NOT exhaustive).
Dr Sharon Rees @reesprescribe
Day 6: #ciproflaxacin Drug-drug interactions; All drugs which can prolong the QT interval. NSAIDs increase risk seizure. Can reduce breakdown and increase concentration of VKA (increased bleeding), lidocaine, clozapine, phenytoin, theophylline and methotrexate (not exhaustive).
Dr Sharon Rees @reesprescribe
Day 7: Resistance to #ciprofloxacin can occur via several mechanisms, including target site mutations (poor antibiotic ‘binding’) and efflux pumps. If there are multiple resistance pathways, then quinolone class resistance may be the result.
Earn Your CPD Certificate
With the help of Prescribing and Therapeutics Training Ltd and the Journal of Prescribing Practice, you can earn your 1-hour CPD certificate
Complete the additional reading suggested below and then answer the ten questions. Please submit the answers to reesprescribe@gmail.com as a numbered list with TRUE/FALSE or the correct A,B,C,D option. If you achieve 8 or more out of ten on the questions, a CPD certificate will be emailed to you.
Further reading on #ciprofloxacin
- Antibacterials, principles of therapy: https://bnf.nice.org.uk/treatment-summary/antibacterials-principles-of-therapy.html
- Ciprofloxacin: https://bnf.nice.org.uk/drug/ciprofloxacin.html
- Ciprofloxacin 500 mg film-coated tablets: https://www.medicines.org.uk/emc/product/3484/smpc
Questions
1. Quinolone antibiotics like ciprofloxacin are all broad spectrum
TRUE or FALSE?
2. Which of the following bacterial species is NOT suspectable to ciprofloxacin?
- Shigella spp
- Streptococcus spp
- Pseudomonas aeruginosa
- Escherichia coli
3. Ciprofloxacin can be used in adults, but not children
TRUE or FALSE?
4. Ciprofloxacin is used as a first-line antibiotic for which of the following:
- Uncomplicated female lower UTI
- Sinusitis
- Acute prostatitis
- Community-acquired pneumonia
5. Which of the following is TRUE?
- Ciprofloxacin inhibits CYP1A2, which causes many drug-drug interactions
- There are no drug-food interactions with ciprofloxacin
- Ciprofloxacin is extensively metabolised in the liver
- The half-life for ciprofloxacin is very short
6. Quinolone antibiotics prevent the bacteria from accessing their coiled-up DNA sections, which has a bactericidal effect
TRUE or FALSE?
7. Tendinopathy and rupture always occur soon after the course is completed
TRUE or FALSE?
8. Which of the following is a common side-effect of ciprofloxacin?
- Photosensitivity reactions
- Blood disorders
- Psychiatric reactions
- Diarrhoea
9. Using NSAIDs together with ciprofloxacin can lower the seizure threshold
TRUE or FALSE?
10. It is not possible for a bacterial infection to be resistant to all quinolone antibiotics
TRUE or FALSE?