Usage
Pefloxacin is a broad-spectrum antibiotic belonging to the fluoroquinolone class. It is prescribed for various bacterial infections, including:
- Urinary Tract Infections (UTIs), such as cystitis and urethritis
- Respiratory Tract Infections (RTIs)
- Gastrointestinal Infections
- Skin and Soft Tissue Infections
- Bone and Joint Infections
- Septicemia
- Prostatitis
- Bacterial Endocarditis
- Neuromeningeal Infections
Pharmacological Classification: Fluoroquinolone Antibiotic
Mechanism of Action: Pefloxacin inhibits bacterial DNA gyrase and topoisomerase IV, enzymes essential for bacterial DNA replication, repair, and recombination. This inhibition leads to bacterial cell death.
Alternate Names
Pefloxacin is the generic name. Brand names can vary regionally; Peflotab and Floxal are mentioned in the provided sources.
How It Works
Pharmacodynamics: Pefloxacin exhibits bactericidal activity by disrupting bacterial DNA replication. This action is concentration-dependent.
Pharmacokinetics:
- Absorption: Pefloxacin is well-absorbed orally, with bioavailability close to 100%. Food intake can enhance absorption.
- Distribution: Pefloxacin achieves high tissue concentrations, surpassing serum levels.
- Metabolism: Primarily hepatic, with N-oxide and norfloxacin as metabolites.
- Elimination: Mainly renal excretion; some biliary elimination occurs. Elimination half-life is approximately 6-12 hours, potentially necessitating dose adjustments in patients with hepatic or renal impairment.
Mode of Action: Pefloxacin targets bacterial DNA gyrase and topoisomerase IV. By binding to these enzymes, pefloxacin prevents the supercoiling and decatenation of DNA, vital processes for bacterial DNA replication, repair, and recombination. The dual targeting of both DNA gyrase and topoisomerase IV minimizes the emergence of bacterial resistance.
Dosage
Standard Dosage
Adults:
Oral: 400 mg twice daily for 7-10 days for most infections. A single dose of 800 mg may be used for uncomplicated gonorrhea or cystitis in women under 65. Intravenous: 400 mg every 12 hours.
Children:
Not recommended for children under 12 years old. Some sources suggest 15-20 mg/kg/day divided twice daily for children older than 12, however caution is warranted given the potential for cartilage erosion.
Special Cases:
- Elderly Patients: Dosage adjustment may be necessary due to altered pharmacokinetics.
- Patients with Renal Impairment: Dosage reduction may be required.
- Patients with Hepatic Dysfunction: Dosage adjustment is essential.
- Patients with Comorbid Conditions: Caution should be exercised in patients with pre-existing CNS disorders, diabetes, or cardiovascular disease.
Clinical Use Cases
Dosage recommendations for specific clinical scenarios, such as intubation, surgical procedures, mechanical ventilation, ICU use, or emergency situations, are not readily available. Standard dosing guidelines should be considered, with adjustments based on patient-specific factors and the severity of infection.
Dosage Adjustments
Dose modifications are necessary based on renal/hepatic function, age, and comorbid conditions.
Side Effects
Common Side Effects:
- Nausea, vomiting, diarrhea
- Headache, dizziness, insomnia
- Skin rash, itching, photosensitivity
Rare but Serious Side Effects:
- Tendonitis, tendon rupture
- Peripheral neuropathy
- QT prolongation, ventricular arrhythmias
- Seizures (especially in patients with pre-existing CNS disorders)
- Hepatic dysfunction
- Hypersensitivity reactions (including swelling of face, lips, tongue, or throat; hives; difficulty breathing)
Long-Term Effects:
Chronic complications from prolonged use are rare but can include peripheral neuropathy and tendon damage.
Adverse Drug Reactions (ADR):
Clinically significant ADRs requiring immediate intervention include severe hypersensitivity reactions, seizures, tendon rupture, and QT prolongation.
Contraindications
- Hypersensitivity to pefloxacin or other quinolones
- Children under 12 years old
- Pregnancy and breastfeeding
- Concomitant use with tizanidine
- History of tendon disorders related to fluoroquinolone use
Drug Interactions
- Antacids (aluminum/magnesium hydroxide, sucralfate): Decreased absorption of pefloxacin. Administer at least 2 hours apart.
- Iron/Zinc salts: Reduced pefloxacin absorption.
- NSAIDs: Increased risk of seizures.
- Anticoagulants (warfarin): Increased risk of bleeding. Monitor INR closely.
- Theophylline: Increased theophylline levels and risk of toxicity. Monitor theophylline levels.
- Antidiabetic medications (sulfonylureas, metformin): Potential for hypoglycemia. Monitor blood glucose levels.
- CYP1A2 inhibitors (cimetidine): May increase pefloxacin levels.
- CYP1A2 inducers (rifampicin): May decrease pefloxacin levels.
- Dairy products: May reduce pefloxacin absorption.
Pregnancy and Breastfeeding
Pefloxacin is contraindicated in pregnancy and breastfeeding due to potential fetal risks and neonatal side effects. The drug can cross the placenta and is excreted in breast milk.
Drug Profile Summary
- Mechanism of Action: Inhibits bacterial DNA gyrase and topoisomerase IV.
- Side Effects: Nausea, vomiting, diarrhea, headache, dizziness, rash, photosensitivity, tendonitis, QT prolongation (rare but serious).
- Contraindications: Hypersensitivity to quinolones, children <12 years, pregnancy, breastfeeding, concomitant use with tizanidine.
- Drug Interactions: Antacids, iron/zinc, NSAIDs, warfarin, theophylline, antidiabetic medications, CYP1A2 inhibitors/inducers.
- Pregnancy & Breastfeeding: Contraindicated.
- Dosage: Adults: 400 mg bid orally or IV. Adjust for renal/hepatic impairment.
- Monitoring Parameters: Renal and hepatic function, blood glucose, INR (if on warfarin), theophylline levels (if co-administered), signs of tendonitis/rupture, ECG (for QT prolongation).
Popular Combinations
No specific popular combinations are mentioned in the provided information.
Precautions
- Obtain a detailed medical history, including allergies, renal/hepatic function, and concomitant medications.
- Advise patients to avoid sun exposure and use sunscreen.
- Monitor for signs of tendonitis, peripheral neuropathy, and CNS toxicity.
- Counsel patients on potential drug interactions and the importance of completing the full course of therapy.
FAQs (Frequently Asked Questions)
Q1: What is the recommended dosage for Pefloxacin?
A: Adults: 400 mg twice daily orally or intravenously. Dosage adjustments are needed for patients with renal or hepatic impairment, elderly patients, and children over 12 (use with caution).
Q2: What are the common side effects of Pefloxacin?
A: Common side effects include nausea, vomiting, diarrhea, headache, dizziness, skin rash, itching, and photosensitivity.
Q3: What are the serious side effects of Pefloxacin?
A: Rare but serious side effects include tendonitis, tendon rupture, peripheral neuropathy, QT prolongation, seizures, and hypersensitivity reactions.
Q4: What are the contraindications for Pefloxacin use?
A: Contraindications include hypersensitivity to pefloxacin or other quinolones, children under 12, pregnancy, breastfeeding, and concomitant use with tizanidine.
Q5: How does Pefloxacin interact with antacids?
A: Antacids can decrease the absorption of pefloxacin. These medications should be taken at least 2 hours apart.
Q6: Can Pefloxacin be used during pregnancy or breastfeeding?
A: No, pefloxacin is contraindicated during pregnancy and breastfeeding due to potential fetal risks and harm to the nursing infant.
Q7: Should Pefloxacin be taken with food?
A: Yes, taking pefloxacin with food can improve absorption and reduce gastrointestinal side effects.
Q8: What should patients be advised regarding sun exposure while taking Pefloxacin?
A: Patients should avoid excessive sun exposure and use sunscreen, as pefloxacin can cause photosensitivity.
Q9: Does Pefloxacin interact with theophylline?
A: Yes, pefloxacin can increase theophylline levels, potentially leading to toxicity. Theophylline levels should be monitored closely if these drugs are co-administered.
Note: This information is current as of February 16, 2025, and is intended for use by qualified medical professionals in India. Prescribing information and recommendations can change; always consult up-to-date resources before making clinical decisions.
