How do you prepare a Voltaren (diclofenac) infusion?

Preparation of Voltaren (Diclofenac) Infusion

For intravenous administration of diclofenac (Voltaren), the standard preparation involves diluting the medication to a concentration of 5 mg/mL in normal saline and administering over 10 minutes to minimize venous complications.

Preparation Method

Materials Needed:

• Diclofenac sodium injection (typically available as 75 mg/3 mL or 75 mg/1 mL)
• Normal saline (0.9% sodium chloride)
• Infusion bag or syringe for administration
• Infusion pump

Dilution Process:

1. Calculate the required dose: Typical dose is 75 mg for adults
2. Dilution ratio: Dilute to a concentration of 5 mg/mL
   • For 75 mg dose: Dilute in 15 mL of normal saline
3. Administration rate: Infuse over 10 minutes

Administration Considerations

Vascular Access:

• Use a large vein, preferably at the antecubital fossa rather than hand veins 1
• Use at least a 23-gauge needle or larger IV catheter

Venous Complications Prevention:

• Critical: Undiluted diclofenac (25 mg/mL) causes high rates of venous thrombosis (85% in hand veins, 58% in arm veins)
• Dilution to 5 mg/mL significantly reduces thrombosis rates (38% hand veins, 8% antecubital fossa veins) 1

Monitoring:

• Observe the IV site during administration for signs of irritation
• Monitor patient for adverse effects including:
  • Gastrointestinal symptoms
  • Cardiovascular effects
  • Hypersensitivity reactions

Alternative Administration Methods

IV Bolus (Recent Development):

• A newer 75 mg/1 mL formulation containing hydroxypropyl-β-cyclodextrin has been developed for IV bolus administration
• Can be administered as a 5-second bolus 2
• Provides faster onset and higher peak concentration than traditional infusions
• Not yet widely available in all markets

Intramuscular Alternative:

• If IV access is difficult, diclofenac can be administered intramuscularly
• Standard dose: 75 mg as deep intramuscular injection
• No dilution required for IM administration

Contraindications and Precautions

• Avoid in patients with:
  • Known hypersensitivity to diclofenac
  • History of asthma precipitated by NSAIDs
  • Active peptic ulceration
  • Severe heart failure
  • Severe renal or hepatic impairment

Clinical Pearls

• Diclofenac has a relatively short elimination half-life, limiting potential for drug accumulation 3
• Dosage adjustments are generally not required in elderly patients or those with mild to moderate renal or hepatic impairment 4
• The medication binds extensively to plasma albumin and achieves substantial concentrations in synovial fluid 4
• Monitor for drug interactions, particularly with aspirin, lithium, digoxin, methotrexate, and cyclosporin 4

Remember that proper dilution and administration rate are crucial to minimize venous complications when giving diclofenac intravenously.