Understanding Contraindications: When Not to Use Cathflo?

October 14, 2025 •

3 min read

Catheter occlusion is a common complication, occurring in up to 25% of central venous access devices (CVADs). While Cathflo (Alteplase) is effective in restoring patency, knowing when not to use Cathflo? is critical for patient safety due to significant risks.

Quick Summary

This overview details the specific situations and patient conditions where Cathflo (Alteplase) is contraindicated, including hypersensitivity, bleeding risks, and mechanical catheter issues. It covers key warnings and precautions.

Key Points

Absolute Contraindication: Do not use in patients with known hypersensitivity to Alteplase or any of its components.
Bleeding Risk: Exercise extreme caution in patients with active bleeding, recent major surgery, bleeding disorders, or uncontrolled hypertension.
Infection Risk: Using Cathflo in an infected catheter may release the infection systemically, causing sepsis.
Mechanical Occlusion: Cathflo is ineffective for non-thrombotic blockages like drug precipitates or catheter kinking.
Drug Interactions: The risk of hemorrhage increases when used with anticoagulants (heparin, warfarin) or antiplatelet drugs (aspirin, NSAIDs).
Administration Pressure: Avoid excessive force during instillation to prevent catheter rupture or clot embolism.
Allergic Reactions: Monitor for signs of hypersensitivity like hives, angioedema, and anaphylaxis during and after use.

Understanding Cathflo (Alteplase) and Its Purpose

Cathflo Activase, with the generic name Alteplase, is a thrombolytic agent used to restore function to central venous access devices (CVADs) blocked by blood clots. It works by converting plasminogen to plasmin, which breaks down the clot. While effective, understanding when not to use Cathflo? is vital due to potential risks. It's important to note that Cathflo only works on blood clots, not blockages from mechanical issues, suture constriction, or drug precipitates.

Absolute Contraindication: Known Hypersensitivity

The only absolute contraindication for Cathflo is a known hypersensitivity to Alteplase or any of its components. Allergic reactions can be severe, including anaphylaxis. Patients with a history of such reactions should not receive Cathflo. Monitoring for hypersensitivity signs during and after administration is necessary.

Critical Warnings and Precautions for Use

Even with the small dose used in Cathflo, the potential for bleeding is a major concern, as it's the most common side effect of thrombolytics. Caution is required for patients with increased bleeding risk, although Cathflo's safety hasn't been specifically tested in these groups for catheter clearance.

Bleeding Risk

Conditions that increase bleeding risk and warrant caution include:

Active internal bleeding.
Recent surgery, obstetrical delivery, or biopsy within 48 hours.
Recent puncture of a non-compressible blood vessel.
Low platelet count or other bleeding disorders.
Severe uncontrolled high blood pressure.
Certain intracranial conditions like aneurysms.
Recent head trauma or intracranial/intraspinal surgery within 3 months.

If serious bleeding occurs in a critical area, Cathflo must be stopped and withdrawn from the catheter immediately.

Risk of Infection

Using Cathflo in a catheter suspected of infection can lead to sepsis by releasing the infection into the bloodstream. Sepsis has been reported after Cathflo treatment. If infection is suspected, Cathflo should be used cautiously with appropriate antibiotics. Aseptic technique during administration is crucial.

Mechanical Catheter Issues

Cathflo is not effective for blockages caused by mechanical problems. Applying excessive pressure during administration can damage the catheter or dislodge the clot into the circulation. Avoiding vigorous suction is also important.

Drug Interactions That Increase Risk

Interactions with other drugs haven't been specifically studied for Cathflo's catheter use. However, combining thrombolytics with medications affecting blood clotting can increase bleeding risk. Use caution with:

Anticoagulants (warfarin, heparin, DOACs).
Antiplatelet agents (aspirin, clopidogrel, NSAIDs).
ACE inhibitors, which might increase angioedema risk with Alteplase.

Comparing Cathflo to Alternatives

Options for an occluded central line depend on the cause of the blockage.


Method	Mechanism of Action	Primary Use Case	Key Risks
Cathflo (Alteplase)	Dissolves blood clots.	Thrombotic occlusion.	Bleeding, hypersensitivity, spreading infection.
Saline/Heparin Push	Mechanical force; prevents new clots.	Partial occlusions; prevention.	Catheter damage, clot embolism, heparin issues.
Ethanol, Sodium Bicarbonate, or Hydrochloric Acid	Dissolves non-clot blockages.	Chemical/drug precipitate occlusions.	Catheter damage, systemic effects.
Catheter Replacement	Remove old, insert new.	Unresolved occlusions, damage, infection.	Risks of new line insertion, infection.

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Conclusion: Prioritizing a Cautious Approach

Cathflo is a useful treatment for thrombotic catheter occlusions. However, careful assessment is necessary to identify when not to use Cathflo due to the risks of hypersensitivity and bleeding. Mechanical blockages and infections also need to be considered, as Cathflo is either ineffective or potentially harmful in these situations. A thorough patient history, medication review, and catheter assessment are crucial for safe use.

Frequently Asked Questions

The only absolute contraindication for Cathflo in its approved use for catheter occlusion is a known hypersensitivity (allergy) to Alteplase or any component in the formulation.

While not an absolute contraindication for this indication, using Cathflo in patients on anticoagulants or antiplatelet drugs significantly increases the risk of bleeding and requires extreme caution and careful assessment by a healthcare provider.

Using Cathflo in an infected line can break up the infected clot and release bacteria into the bloodstream, potentially causing a systemic infection or sepsis.

There are no adequate and well-controlled studies of Cathflo in pregnant women. It should only be used during pregnancy if the potential benefit justifies the potential risk to the fetus, as animal studies have shown potential embryocidal effects at high doses.

Before using Cathflo, healthcare providers should first consider and rule out non-thrombotic causes of occlusion, such as catheter malposition, mechanical failure (kinks), or blockages from drug precipitates.

Signs of serious bleeding include sudden severe headache, dizziness, weakness, bleeding that won't stop, black or bloody stools, or coughing up blood. These require immediate medical attention.

No, Cathflo is a thrombolytic agent designed to dissolve blood clots (thrombi). It is not effective against occlusions caused by drug precipitates, lipid deposits, or other non-thrombotic materials.