Vancomycin

# Vancomycin ## Overview - **Classification**: Glycopeptide antibiotic - **Mechanism**: Inhibits bacterial cell wall synthesis by binding to D-Ala-D-Ala precursors, interfering with peptidoglycan cross-linking. ## Primary Indications 1. **Serious Gram-Positive Infections** - Treatment of MRSA, MRSE, and other susceptible Gram-positive bacteria. 2. **Clostridioides difficile Infection (CDI)** - Oral treatment for severe or recurrent CDI. 3. **Endocarditis Prophylaxis** - For high-risk patients undergoing specific procedures. ## Adult Dosing ### Standard Dosing **Systemic Infections (e.g., MRSA bacteremia, Sepsis, Endocarditis)** - **Dose**: **15-20 mg/kg** per dose (based on actual body weight) - **Frequency**: Every **8-12 hours** - **Route**: Intravenous (IV) infusion over **at least 60 minutes** - **Maximum Dose**: Typically **2 g** per dose; daily maximum often **60 mg/kg/day**. **Clostridioides difficile Infection (CDI)** - **Dose**: **125 mg** - **Frequency**: Four times daily (**QID**) - **Route**: Oral (PO) - **Duration**: **10 days** for initial episode. - **Special Consideration**: For severe/fulminant CDI, dose is **500 mg QID PO**. ### Dose Adjustments - **Renal Impairment**: Requires significant dose reduction or extended dosing interval. * Adjust based on **CrCl** and target trough levels (e.g., **CrCl < 50 mL/min** often needs interval extension or dose reduction). * Close monitoring of **serum trough levels** and **renal function** is essential. - **Hepatic Impairment**: No specific dose adjustment typically needed. - **Elderly Patients**: Often have reduced renal function; use age-appropriate **CrCl estimation** and monitor closely. ## Pediatric Dosing ### Neonates (0-28 days) - **Dose**: **10-15 mg/kg** per dose - **Frequency**: Every **12-24 hours** (depends on post-natal age and gestational age) - **Maximum**: Refer to specific neonatal guidelines; avoid exceeding **30-45 mg/kg/day**. - **Special Notes**: Extended dosing intervals common due to immature renal function. Infuse over **60-90 minutes**. ### Infants (1-12 months) - **Dose**: **15 mg/kg** per dose - **Frequency**: Every **6-8 hours** - **Maximum**: Do not exceed **60-80 mg/kg/day**. - **Special Notes**: Infuse over **60 minutes**. Close monitoring of troughs is crucial due to variable clearance. ### Children (1-12 years) - **Dose**: **15 mg/kg** per dose - **Frequency**: Every **6 hours** - **Maximum**: Typically **4 g/day**, though **60-80 mg/kg/day** is often the guideline limit. - **Special Notes**: Often higher doses/frequencies than adults due to faster clearance. ### Adolescents (13-18 years) - **Dose**: Generally follow **adult dosing** guidelines (**15-20 mg/kg** per dose). - **Maximum**: Up to **2 g** per dose. - **Special Notes**: Base dosing on weight, renal function, and target trough levels. ## Safety Information ### Contraindications - **Absolute**: Documented **hypersensitivity** to vancomycin. - **Absolute**: Previous occurrence of **severe Vancomycin-Induced Redman Syndrome (VIRS)**. - **Relative**: Pre-existing **hearing loss** (caution due to ototoxicity risk). ### Common Adverse Effects - **Very Common (>10%)**: **Redman Syndrome** (flushing, rash, itching, tachycardia during rapid infusion), phlebitis. - **Common (1-10%)**: Nephrotoxicity (elevated Cr, BUN), fever, nausea, chills. - **Serious but Rare**: Ototoxicity (hearing loss, tinnitus, vertigo), severe skin reactions (SJS/TEN), neutropenia, thrombocytopenia. ### Key Drug Interactions - **Nephrotoxic Agents (e.g., aminoglycosides, NSAIDs, loop diuretics, cyclosporine)**: Increased risk of **nephrotoxicity**. Monitor renal function closely. - **Ototoxic Agents (e.g., loop diuretics, aminoglycosides)**: Increased risk of **ototoxicity**. Avoid concomitant use if possible. - **Anesthetic Agents**: May increase risk of **Redman Syndrome** (consider pre-medication or slower infusion). ## Monitoring & Follow-up - **Before Treatment**: Baseline **renal function (SCr, BUN)**. - **During Treatment**: * **Serum Trough Levels**: Typically obtained **before 4th or 5th dose** (at steady state). Target: **10-20 mcg/mL** (15-20 mcg/mL for severe infections). * **Renal Function**: Monitor **SCr and BUN** daily or every 1-3 days depending on clinical status. * **Clinical Signs**: Watch for signs of nephrotoxicity, ototoxicity (if high risk), and Redman Syndrome. ## Clinical Pearls - 💡 **Infusion Rate**: Infuse slowly (minimum **1 hour for every 500 mg**) to prevent or minimize Redman Syndrome. - 💡 **Oral vs. IV**: Oral vancomycin is effective **only for C. difficile** as it is poorly absorbed systemically. - 💡 **Therapeutic Drug Monitoring**: Trough levels are critical for optimizing efficacy and minimizing toxicity, especially with renal impairment. - 💡 **Hydration**: Maintain adequate hydration to help prevent nephrotoxicity. > **⚠️ Important**: This information is for educational purposes only. Always consult current prescribing information, local guidelines, and clinical judgment before prescribing.