A 2012 meta-analysis evaluated use of thrombolytics for treating central venous catheter (CVC) occlusions including reteplase, tenecteplase, and alfimeprase. Studies for reteplase show 67-74% clearance after 30–40 minutes, with overall clearance of 80-95% (86% overall clearance). A max dose of 0.4 U was determined to be safe without increased risk of complications. Tenecteplase had demonstrated 81 to 87% clearance initially and 80 to 81% maintenance after 7 days. The dose investigated was weight-based, with weight <30 kg receiving 110% of CVC lumen volume with 2 mg/2 mL; and weight > 30 kg receiving 2 mL of 2 mg/2mL. A study for alfimeprase found 50% clearance after 15 minutes with alfimeprase vs 0% for alteplase, and overall 80% vs 62% clearance. The study utilized 0.3, 1.0, and 3.0 mg doses, which were all deemed more successful than alteplase. Reteplase appears most effective initially at 30–40 minutes, with higher clearance rates than others. It also performs well with longer dwell times and multiple doses. However, more data are required to confirm these findings. [1]
A 2019 meta-analysis evaluated interventions used to treat obstructive events, whether thrombotic or non-thrombotic, in long-term CVC (LT-CVC) in cancer patients. The drugs used for restoration of catheter function were urokinase (53.3%), alteplase (20%), alteplase (13.3%), reteplase (6.7%), recombinant urokinase (6.7%), and staphylokinase (6.7%). A success rate of 84% was found with use of tenecteplase (95% CI, 77.32% to 90.01%) from a sample size of 234 catheters. Of note, the analysis was limited to 2 studies evaluating use of tenecteplase. See Tables 1-2 for more details on tenecteplase for treatment of occluded CVCs. [2]
Another 2019 systematic review and meta-analysis investigated use of alteplase for treatment of occlusions in long-term central venous catheters in pediatric patients with cancer. Of the 10 total trials included, 6 utilized alteplase while the other 4 used urokinase or streptokinase. In most studies, use of low-dose alteplase was reserved for smaller children. Overall, the restoration rate ranged from 50% to 97.5% with the administration time ranging from 30 minutes to 48 hours. Pooled results indicated an overall success rate of 88% (95% confidence interval [CI] 80% to 95%). Included studies reflected significant heterogeneity (I2= 59.2%) due to large dose variations, ranging from 0.5 mg/0.5 mL to 2 mg/3 mL, and varying infusion times, convoluting pooled outcomes when attempting to focus on a single dosing regimen. Despite this, alteplase was considered to be generally well-tolerated in pediatric patients, with a low incidence of adverse events when used to restore central catheter patency. Note that urokinase and streptokinase are no longer commercially available in the United States. Specific data for use of tenecteplase was not discussed. [3]