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Introduction: I have been receiving repeated
requests for information regarding alteplase and its use in catheter
occlusions. I am including a general overview as well links to other
sites that have published information in this area. If you currently
have established guidelines you would like to post, please use the form
at the bottom of this page.
Since the halting of the manufacture of urokinase
by the FDA, there has been additional focus on alternatives to be
used for catheter clearance. The establishment of appropriate guidelines,
stability and batch processing in order to reduce costs have been
examined.
Because of the effectiveness of the 0.5 mg dose as an initial dose, this
appears to be the best starting point when utilizing a stepped-dosage
protocol for clearing catheter occlusions. A study conducted at
the University of Wisconsin Hospital and Clinics, which included
patients with various degrees of catheter occlusion (from partial to
complete occlusion) had found that 50 catheters in the study (86.2%)
were cleared with alteplase 0.5 mg, 5 catheters (8.6%) were cleared with
dose escalation to 1 mg and 1 catheter (1.7%) was cleared after dose
escalation to 2 mg.1
Stability of batch
processed syringes:
The study at UWHC revealed the following:
| Concentration |
Stability
* |
Storage
temp |
| 1 & 2 mg/ml |
14 days |
2° Celsius |
| 0.5 mg/ml |
28 days |
2° Celsius |
| The 0.5, 1, 2 mg/ml
concentrations maintained adequate stability up to 28 days if
stored for 14 days at -25 or -70° Celsius, followed by 14
days at 2° Celsius. 1 |
*Stability defined as the maintenance of
sufficient antifibrinolytic activity at the end of the prescribed time.
Preparation:
Most protocols that have been established utilize the
50mg vial of alteplase. Once diluted, 2 mg of drug is removed and
placed into 5 ml syringes. Sterile water is then added to each syringe
to bring the volume up to the desired level (usually 1 to 4 ml depending
on the desired concentration: 0.5 to 2 mg/ml). Average storage
requirements are similar to the findings listed above.
Utilization:
Thawing: Once the syringes are thawed, they are
stable for only 8 hours. When clearing a catheter, an adequate
amount of sodium chloride (preservative-free) must be added to
sufficiently fill the catheter. I am including links to a few nursing
sites below that describe the steps involved. Initial doses on
average range from 0.5 to 2 mg. Dwell times range from 1 to 4 hours. In all cases, mechanical
obstruction or pump failure needs to be ruled out.
References:
1. Davis SN, Vermeulen L, Banton J, Schwartz BS, Williams
EC. Activity and dosage of alteplase dilution for clearing occlusions of
venous-access devices.
Am J Health Syst Pharm. 2000 Jun 1;57(11):1039-45.
2. Hooke C. Recombinant tissue plasminogen
activator for central venous access device occlusion. J Pediatr Oncol
Nurs. 2000 Jul;17(3):174-8. Review.
3. Wiernikowski JT, Crowther M, Clase CM,
Ingram A, Andrew M, Chan AK. Stability and sterility of recombinant
tissue plasminogen activator at -30 degrees Celsius. Lancet. 2000 Jun
24;355(9222):2221-2.
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