What is a safe dose of Cathflo (alteplase) for dissolving a clot from a Peripherally Inserted Central Catheter (PICC) line?

Safe Dosing of Cathflo (Alteplase) for PICC Line Clot Dissolution

The safe and effective dose of Cathflo (alteplase) for dissolving clots in PICC lines is 2 mg in 2 mL for patients weighing ≥30 kg, and 110% of the internal lumen volume (not to exceed 2 mg in 2 mL) for patients weighing <30 kg. 1

Dosing Protocol

Standard Adult Dosing

• Dose: 2 mg in 2 mL (concentration of 1 mg/mL)
• Administration method: Instill directly into the occluded catheter lumen
• Dwell time: Allow to dwell for 30-120 minutes
• Assessment: Check catheter function after 30 minutes
• Second dose: If catheter remains occluded after 120 minutes, a second dose may be administered

Pediatric Dosing (<30 kg)

• Dose: 110% of the internal lumen volume of the catheter, not to exceed 2 mg in 2 mL
• Administration method: Same as adult protocol
• Maximum: Do not exceed total of 4 mg (two 2-mg doses) 1

Administration Procedure

1. Preparation:

   • Reconstitute Cathflo Activase to 1 mg/mL using 2.2 mL of Sterile Water for Injection
   • Do not use Bacteriostatic Water for Injection
   • Mix by gentle swirling until completely dissolved (within 3 minutes)
   • Use within 8 hours of reconstitution when stored at 2-30°C (36-86°F)

2. Administration:

   • Withdraw appropriate dose from reconstituted vial
   • Instill solution into the occluded catheter
   • After 30 minutes, assess catheter function by attempting to aspirate blood
   • If still occluded, continue dwell time up to 120 minutes
   • If catheter remains occluded after 120 minutes, a second dose may be administered 1

3. After successful clearance:

   • Aspirate 4-5 mL of blood in patients ≥10 kg (or 3 mL in patients <10 kg) to remove Cathflo and residual clot
   • Gently irrigate the catheter with 0.9% Sodium Chloride Injection

Efficacy and Safety

Alteplase has demonstrated high efficacy rates for restoring PICC line function:

• 75% success rate after one dose
• 85-93% success rate after two doses 2, 3

The safety profile is excellent with extremely low rates of serious adverse events:

• No reported intracranial hemorrhage in clinical trials
• Rare serious adverse events (0.3% gastrointestinal bleeding, 0.3% thrombosis, and 0.4% sepsis) 2

Special Considerations

• Alternative dosing: Some studies have shown that lower doses (1 mg/1 mL) may be equally effective and more cost-effective in certain settings 4
• Neonates/premature infants: Lower doses (0.3 mg/0.3 mL) have been used successfully in premature infants 5
• Pediatric patients: Alteplase is safe and effective in pediatric populations with a cumulative success rate of 82.9% after two doses 6

Important Precautions

• Ensure the catheter is not mechanically occluded before administering Cathflo
• Do not forcefully flush the catheter as this may cause catheter rupture or embolization
• Do not mix other medications with Cathflo Activase solution
• Discard any unused solution after the procedure

Alteplase is the agent of choice for thrombotic catheter occlusions in PICC lines, with strong evidence supporting its efficacy and safety profile across different patient populations 7, 8.