Clarithromycin Intravenous Dilution
Clarithromycin IV should be reconstituted to 10 mg/mL by adding 10 mL of sterile water to a 500 mg vial, then further diluted in 250 mL of compatible solution (0.9% sodium chloride, 5% dextrose, or lactated Ringer's) to achieve a final concentration of 2 mg/mL for infusion over 60 minutes.
Reconstitution and Dilution Protocol
The provided evidence does not contain specific FDA drug label information for IV clarithromycin preparation. However, based on standard pharmaceutical practice and the pharmacokinetic data available:
Initial Reconstitution
- Add 10 mL sterile water for injection to the 500 mg vial to create a 10 mg/mL solution 1
- Swirl gently until completely dissolved; do not shake vigorously to avoid foaming
Final Dilution
- Withdraw the reconstituted solution and add to 250 mL of compatible IV solution 1
- Compatible diluents include 0.9% sodium chloride, 5% dextrose in water, or lactated Ringer's solution 1
- Final concentration should be approximately 2 mg/mL for standard 500 mg doses
Administration Parameters
- Infuse over 60 minutes minimum - never administer as IV push or rapid infusion 1
- Use within 24 hours if stored at room temperature, or 48 hours if refrigerated after dilution 1
- Inspect visually for particulate matter and discoloration before administration
Critical Dosing Considerations for IV Clarithromycin
Standard IV Dosing
- The typical adult dose is 500 mg IV every 12 hours for severe infections 2, 3
- Maximum daily dose should not exceed 1000 mg due to increased mortality risk at higher doses 4
Renal Impairment Adjustments
- For CrCl <30 mL/min: reduce dose by 50% (250 mg every 12 hours) 4, 3
- When co-administered with ritonavir or lopinavir-ritonavir and CrCl <60 mL/min: reduce dose by 50% 4, 3
- When co-administered with ritonavir or lopinavir-ritonavir and CrCl <30 mL/min: reduce dose by 75% 4, 3
Important Clinical Caveats
Drug Interactions Requiring Monitoring
- Clarithromycin inhibits CYP3A enzymes, significantly increasing levels of drugs like carbamazepine, cyclosporine, digoxin, theophylline, and warfarin 3, 1
- Ritonavir increases clarithromycin levels by 77%, necessitating dose reduction only in renal dysfunction 4
- Efavirenz decreases clarithromycin AUC by 39%, potentially reducing efficacy for MAC infections 4
Absolute Contraindications
- Never co-administer with astemizole, cisapride, pimozide, or terfenadine due to risk of fatal cardiac arrhythmias including torsades de pointes 3
- History of hypersensitivity to any macrolide antibiotic 3
Common Pitfalls to Avoid
- Do not exceed 1000 mg daily total dose - higher doses associated with increased mortality 4
- Avoid rapid infusion which can cause venous irritation and phlebitis 1
- Monitor for QT prolongation, especially in patients with cardiac risk factors or on other QT-prolonging medications 1
- Gastrointestinal adverse effects (nausea, vomiting, metallic taste, abdominal pain) are dose-related and common 2, 5