Why Amiodarone is Mixed with Dextrose
Amiodarone is mixed with dextrose (D5W) rather than normal saline because it forms precipitates with saline solutions, which would compromise drug delivery and potentially cause adverse effects. 1
Compatibility and Stability Considerations
Amiodarone has specific compatibility requirements that necessitate its dilution in dextrose:
- Amiodarone forms precipitates when mixed with normal saline and certain other drugs 1, 2
- The FDA drug label specifically recommends that amiodarone infusions exceeding 2 hours must be administered in glass or polyolefin bottles containing D5W 1
- Stability studies confirm that amiodarone maintains its chemical integrity when mixed with 5% dextrose injection for up to 24 hours 2
Administration Guidelines
When administering intravenous amiodarone:
- Concentrations should not exceed 2 mg/mL for infusions longer than 1 hour to reduce the risk of peripheral vein phlebitis 1
- Higher concentrations (>3 mg/mL) in D5W have been associated with a high incidence of peripheral vein phlebitis 1
- Amiodarone must be delivered by a volumetric infusion pump, as the surface properties of solutions containing injectable amiodarone can alter drop size, potentially leading to underdosage by up to 30% if drop counter infusion sets are used 1
Safety Considerations
The dextrose diluent helps manage some of amiodarone's potential adverse effects:
- Hypotension is a common side effect of IV amiodarone, occurring in approximately 16% of patients 3
- The cosolvents in amiodarone formulations (polysorbate 80 and benzyl alcohol) are primarily responsible for the hypotensive effects 4
- Proper dilution in dextrose helps minimize the risk of hypotension, though the effect may still persist throughout the maintenance infusion period 4
Practical Administration Points
- Administer through a central venous catheter dedicated to that purpose whenever possible 1
- Use an in-line filter during administration 1
- Do not use evacuated glass containers for admixing, as incompatibility with a buffer in the container may cause precipitation 1
- Inspect the solution for particulate matter and discoloration prior to administration - solution should be clear 1
Important Cautions
- Rapid infusion or excessive concentrations of amiodarone have been associated with serious adverse effects including hepatocellular necrosis and acute renal failure 1
- Do not use plastic containers in series connections due to risk of air embolism 1
- Amiodarone adsorbs to polyvinyl chloride (PVC) tubing, which can affect dosing 1
By following these guidelines and understanding why amiodarone requires dextrose as a diluent, clinicians can safely administer this important antiarrhythmic medication while minimizing risks to patients.