Levofloxacin

# Levofloxacin ## Overview - **Classification**: Fluoroquinolone antibiotic. - **Mechanism**: Inhibits bacterial DNA gyrase and topoisomerase IV, essential enzymes for DNA replication and repair, leading to bacterial cell death. ## Primary Indications 1. **Community-Acquired Pneumonia (CAP)** - Caused by susceptible organisms. 2. **Acute Bacterial Exacerbation of Chronic Bronchitis (ABECB)** - When other options are unsuitable. 3. **Acute Bacterial Sinusitis (ABS)** - When other options are unsuitable. 4. **Complicated Skin and Skin Structure Infections (cSSSI)** - Due to susceptible organisms. 5. **Complicated Urinary Tract Infections (cUTI) & Pyelonephritis** - Caused by susceptible organisms. 6. **Chronic Bacterial Prostatitis** - Caused by susceptible organisms. ## Adult Dosing ### Standard Dosing **Community-Acquired Pneumonia (CAP)** - **Dose**: **750 mg** - **Frequency**: Once daily - **Route**: PO/IV - **Duration**: 5 days **Acute Bacterial Exacerbation of Chronic Bronchitis (ABECB)** - **Dose**: **500 mg** - **Frequency**: Once daily - **Route**: PO/IV - **Duration**: 7 days **Acute Bacterial Sinusitis (ABS)** - **Dose**: **500 mg** - **Frequency**: Once daily - **Route**: PO/IV - **Duration**: 10-14 days **Complicated Skin and Skin Structure Infections (cSSSI)** - **Dose**: **750 mg** - **Frequency**: Once daily - **Route**: PO/IV - **Duration**: 7-14 days **Complicated Urinary Tract Infections (cUTI) & Pyelonephritis** - **Dose**: **750 mg** - **Frequency**: Once daily - **Route**: PO/IV - **Duration**: 5 days **Chronic Bacterial Prostatitis** - **Dose**: **500 mg** - **Frequency**: Once daily - **Route**: PO/IV - **Duration**: 28 days ### Dose Adjustments - **Renal Impairment**: Adjust based on Creatinine Clearance (CrCl). - **CrCl 20-49 mL/min**: Initial **750 mg**, then **250-500 mg** q24h. - **CrCl 10-19 mL/min**: Initial **750 mg**, then **250 mg** q48h. - **HD/CAPD**: Initial **750 mg**, then **250 mg** q48h post-dialysis. - **Hepatic Impairment**: No dosage adjustment required. - **Elderly Patients**: No specific adjustment; monitor renal function closely. ## Pediatric Dosing **Note**: Use in pediatric patients (under 18 years) is generally avoided due to the risk of musculoskeletal adverse events. It is reserved for severe or life-threatening infections where benefits outweigh risks and alternative treatments are not feasible. ### Neonates (0-28 days) - **Use**: Generally **NOT recommended**. - **Indication (limited)**: Severe infections (e.g., resistant Gram-negative sepsis) where no alternatives exist. - **Dose (if used)**: **5-8 mg/kg/dose** - **Frequency**: Every 12 hours - **Route**: IV/PO (oral solution may be used). - **Maximum**: Not well-established. - **Special Notes**: High risk of musculoskeletal toxicity. Close monitoring for arthropathy. ### Infants (1-12 months) - **Use**: Generally **NOT recommended**. - **Indication (limited)**: Severe, multi-drug resistant infections. - **Dose (if used)**: **5-10 mg/kg/dose** - **Frequency**: Every 12 hours - **Route**: IV/PO (oral solution may be used). - **Maximum**: **250 mg/dose** (approximate). - **Special Notes**: Monitor for joint pain/swelling. ### Children (1-12 years) - **Use**: Generally **NOT recommended for routine infections.** - **Indication (specific)**: Post-exposure prophylaxis/treatment for inhalational anthrax, plague. - **Dose (for anthrax/plague)**: **10 mg/kg/dose** - **Frequency**: Every 12 hours - **Route**: IV/PO (tablets/oral solution). - **Maximum**: **500 mg/dose** (or **750 mg/dose** for anthrax treatment). - **Special Notes**: Assess risk vs. benefit carefully. ### Adolescents (13-18 years) - **Use**: Generally **NOT recommended for routine infections.** - **Indication (specific)**: Severe, resistant infections where adult-level doses are appropriate. - **Dose (if used)**: Approaches adult dosing, typically **500 mg** or **750 mg**. - **Frequency**: Once daily - **Route**: IV/PO - **Maximum**: **750 mg/day**. - **Special Notes**: Similar risks as adults, including tendon rupture. ## Safety Information ### Contraindications - **Absolute**: Hypersensitivity to levofloxacin or other fluoroquinolones. - **Absolute**: History of tendon disorders related to fluoroquinolone use. - **Absolute**: Myasthenia Gravis (may exacerbate muscle weakness). - **Absolute**: Co-administration with Tizanidine. - **Relative**: Children and adolescents (<18 years) for non-life-threatening infections. ### Common Adverse Effects - **Very Common (>10%)**: Nausea, diarrhea, headache. - **Common (1-10%)**: Vomiting, constipation, abdominal pain, dizziness, insomnia, rash, photosensitivity. - **Serious but Rare**: Tendon rupture/tendinitis, peripheral neuropathy, C. difficile infection, QT prolongation/arrhythmia, seizures, hypo/hyperglycemia, psychiatric effects. ### Key Drug Interactions - **Antacids (Mg/Al), Sucralfate, Iron/Zinc supplements**: Decreased levofloxacin absorption. - Administer levofloxacin at least **2 hours before or 2 hours after** these agents. - **Warfarin**: Increased INR/bleeding risk. - Monitor INR closely. - **Corticosteroids**: Increased risk of tendon rupture. - Avoid concomitant use if possible, especially in elderly. - **NSAIDs**: Increased risk of CNS stimulation and seizures. - Use with caution. - **Antiarrhythmics (Class IA/III), TCAs, Macrolides**: Increased risk of QTc prolongation. - Avoid co-administration if possible; monitor ECG. - **Sulfonylureas/Insulin**: Risk of hypo- or hyperglycemia. - Monitor blood glucose closely. ## Monitoring & Follow-up - **Before Treatment**: Baseline renal function (CrCl), electrolytes (K, Mg). - **During Treatment**: Monitor for tendon pain/swelling, peripheral neuropathy symptoms (tingling, numbness). - **During Treatment**: Watch for signs of C. difficile infection (severe diarrhea). - **Clinical Signs**: Monitor for allergic reactions, seizure activity, psychiatric changes, blood glucose fluctuations. ## Clinical Pearls - 💡 **Black Box Warning**: Levofloxacin carries warnings for tendonitis/tendon rupture, peripheral neuropathy, CNS effects, and worsening of myasthenia gravis. - 💡 **Photosensitivity**: Advise patients to use sun protection and avoid excessive sun exposure. - 💡 **Hydration**: Encourage adequate hydration to prevent crystalluria (rare). - 💡 **Complete Course**: Emphasize completing the entire prescribed course, even if feeling better. - 💡 **Oral Admin**: Administer oral dose with a full glass of water. - 💡 **IV Infusion**: Infuse IV doses (500mg/750mg) over **60-90 minutes** to minimize infusion-related reactions. > **⚠️ Important**: This information is for educational purposes only. Always consult current prescribing information, local guidelines, and clinical judgment before prescribing.