Rx Update: February 2002

Alteplase for Catheter Clearance

Mary Ross, R.Ph., M.B.A., Barbara Mutnick, R.Ph., M.H.P., Joan Murhammer, R.Ph., Pharmacotherapy Evaluation and Consultation Service, Department of Pharmaceutical Care
Peer Review Status: Internally Reviewed

Alteplase (Cathflo™ Activase®- Genentech) is a tissue plasminogen activator (t-PA) indicated for the clearance of catheter dysfunction caused by thrombus formation. Alteplase is an enzyme that binds to fibrin, converting plasminogen to plasmin. This product replaces the extemporaneously prepared alteplase 2 mg/2 ml frozen syringes previously made by the Pharmacy.

It is important to remember that catheter dysfunction may be caused by a variety of conditions other than thrombus formation (e.g., catheter malposition, mechanical failure, constriction by a suture, and lipid deposits or drug precipitate). Other mechanisms of catheter clearance should be considered prior to the use of alteplase. Caution should be used in patients who have a high risk for bleeding, thrombocytopenia, other hemostatic defects, or a high risk for embolic complications.

Each vial of Cathflo™ Activase® contains 2.2 mg of alteplase to deliver 2 mg/2 ml once reconstituted. The recommended adult dose is 2 mg. Pediatric patients will continue to use the 0.5 mg/0.5 ml frozen syringes.

Instructions for Preparation of Solution

  1. Refrigerate vials until ready to use.
  2. Reconstitute immediately prior to use because vials contain no preservative. The solutions must be used within 8 hours of reconstitution.
  3. Reconstitute vial with 2.2 ml of sterile water for injection to a final concentration of 1 mg/1 ml.
  4. Allow vial to stand undisturbed to allow large bubbles to dissipate; slight foaming may occur.
  5. Mix gently by swirling vial. DO NOT SHAKE. Complete dissolution should occur within 3 minutes.
  6. No other medications should be added to the solution.

Steps for Instillation into Catheter

Step 1:

Withdraw 2 ml (2 mg) of the reconstituted solution from the vial.

Step 2:

Instill dose into occluded catheter.

Step 3:

After 30 minutes of dwell time, assess catheter function by attempting to aspirate blood. If catheter is functional, go to Step 6. If not, continue onto Step 4.

Note: Vigorous suction and excessive compression of the catheter should be avoided during procedure for catheter clearance.

Step 4:

After 120 minutes of dwell time, assess catheter function. If functional, go to Step 6. If not, continue onto Step 5.

Step 5:

A second 2 mg dose of alteplase may be instilled. Repeat procedure beginning with Step 1.

Step 6:

If function has been restored, aspirate approximately 4 to 5 ml of blood to remove drug and residual clot followed by irrigation with sodium chloride 0.9%.

  • Discard any unused solution.

Simethicone Tablets -- Dose Standardization

The Pharmacy and Therapeutics Subcommittee has approved rounding simethicone doses to the nearest 80 mg dose for adult patients. Simethicone is not systemically absorbed and has a very wide therapeutic index. In addition, simethicone tablets are commercially available only as 80 mg tablets. Therefore, beginning February 1, 2002, Pharmacy will automatically substitute 80 mg tablets when orders for 40 mg doses are written for adult patients.

 

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