Quinolones

Fluoroquinolones are powerful broad-spectrum antibiotics with activity against many Gram-negative and some Gram-positive pathogens. However, due to rising resistance and serious safety concerns, they’re reserved for specific cases—and should be handled with caution in pharmacy practice.

General Principles of Link:

Anti-Infectives

Medicine Link

1. Ciprofloxacin

2. Moxifloxacin

3. Norfloxacin

Mechanism of Action

Fluoroquinolones are bactericidal:

• Inhibit DNA gyrase and topoisomerase IV

• Prevent DNA supercoiling → halts bacterial replication

  
  

Fluoroquinolone Drugs at a Glance

Drug	Spectrum	Key Use	Caution
Ciprofloxacin	Strong Gram-negative incl. P. aeruginosa	Complicated UTI, Salmonella, bone infections	Weak Gram-positive cover
Moxifloxacin	Strong Gram-positive + anaerobes	Severe CAP, sinusitis, MDR-TB	QT risk, avoid with cardiac history
Norfloxacin	Mostly urinary Gram-negatives	Resistant UTIs, traveller’s diarrhoea	Poor systemic bioavailability
Ofloxacin	Broad, similar to cipro	Leprosy (SAS)	Less active against Pseudomonas

Indications – When to Use Fluoroquinolones

Condition	Agent(s) of Choice
Complicated UTI, prostatitis	Ciprofloxacin, Norfloxacin
CAP with penicillin allergy or Legionella	Moxifloxacin
Traveller’s diarrhoea, shigellosis	Norfloxacin
MDR-TB, severe skin infections	Moxifloxacin
Bone/joint infection, P. aeruginosa	Ciprofloxacin

⚠️ Always verify resistance data before initiating therapy.

Precautions & Contraindications

Risk Factor	Fluoroquinolone Risk
Tendinopathy	Risk ↑ with age, steroids, prior rupture
Neuropathy	May be irreversible; stop if symptoms
QT Prolongation	Moxi > Ciprofloxacin > Norfloxacin
Seizure/Epilepsy	May lower seizure threshold
Myasthenia Gravis	Worsening muscle weakness reported
Pregnancy	Avoid unless life-threatening
Children	Use only in serious infections (e.g. CF, febrile neutropenia)

Adverse Effects Summary

Frequency	Adverse Effects
Common (>1%)	Nausea, diarrhoea, rash, abdominal pain
Infrequent	Headache, insomnia, myalgia, raised LFTs
Rare (<0.1%)	Tendon rupture, SJS/TEN, seizures, C. difficile, aortic aneurysm/dissection, neuropathy, arrhythmias

Individual Drug Profiles

🧪 Ciprofloxacin

Ciprofloxacin

Use: UTI, bone/joint infection, Pseudomonas, typhoid, meningococcal prophylaxis

Doses:

• Oral: 250–500 mg BD (max 1.5 g/day)

• IV: 200–400 mg BD

• Child: 10–20 mg/kg BD (max 400 mg/dose)

Practice Tips:

• Excellent tissue distribution (except CSF)

• Avoid dairy, iron, or antacids around dose

• Increase fluid intake to prevent crystalluria

🗣️ Counselling:

• Take 1 hr before or 2 hrs after food

• Avoid sunlight; report tendon or nerve symptoms

• May enhance caffeine effects

• Brands: Ciprofloxacina, C-Flox, Ciprola

  
  

🧪 Moxifloxacin

 Moxifloxacin

Use: Severe CAP, MDR-TB, sinusitis, anaerobic cover

Dose: 400 mg once daily (oral or IV)

• IV over ≥60 minutes

Practice Tips:

• Avoid in QT prolongation history

• More effective for Gram-positives than ciprofloxacin

• Avoid in UTI (not concentrated in urine)

🗣️ Counselling:

• Avoid antacids/iron/zinc near dose

• Report palpitations, jaundice, or fainting

• Monitor for tendon/nerve issues

• Brands: Avelox, Moximeda

  
  

🧪 Norfloxacin

Use: UTIs, prostatitis, traveller’s diarrhoea, prophylaxis in cirrhosis

Doses:

• 400 mg BD (3–14 days depending on indication)

• Max: 800 mg/day

Practice Tips:

• Poor systemic absorption → only use for GI/urinary infections

• Adjust dose in CrCl <30 mL/min

• Superinfection risk (e.g., Candida, Enterococcus) in long courses

🗣️ Counselling:

• Take 1 hr before or 2 hrs after food

• Avoid sunlight, alcohol, and antacids

• Brands: Norfloxacin (generic)

Auxe Tips

• Restrict Use: Only dispense for confirmed/resistant infections

• Tendon Risk: Stop drug immediately if pain/inflammation

• Nerve Damage: Even a single dose can trigger symptoms

• QT Screening: Ask about heart disease or meds like amiodarone

• Dosing Timing: Separate from calcium, iron, dairy

Community Counselling Guide

Advice	Patient Understanding
Before/after food	Take on empty stomach; avoid milk, supplements
Sun protection	Wear sunscreen and protective clothing
Nerve or tendon pain	Stop drug & see doctor immediately
Caffeine interaction	May feel jittery – reduce caffeine intake
Alcohol caution	May worsen dizziness or sedation

🔚 Final Note from Auxe Pharma

Fluoroquinolones are no longer general-use antibiotics. As resistance increases and side effect risks mount, their role is shrinking—but still lifesaving in the right hands.

🧠 For intern pharmacists:

• Screen carefully.

• Counsel clearly.

• Monitor closely.

Let’s preserve fluoroquinolone effectiveness for the patients who truly need them.