What is Clexane? An Overview of This Anticoagulant Medication

October 11, 2025 •

3 min read

Clexane is the brand name for enoxaparin, a low molecular weight heparin (LMWH) used to prevent and treat serious blood clots. It is often prescribed following surgery or for medical conditions that increase the risk of venous thromboembolism.

Quick Summary

Clexane is an injectable anticoagulant, known as enoxaparin, that prevents new blood clots and stops existing ones from growing. It is used for conditions like deep vein thrombosis, pulmonary embolism, and certain heart problems, requiring careful administration and monitoring.

Key Points

Enoxaparin Sodium: Clexane is the brand name for the anticoagulant medication enoxaparin sodium.
Mechanism of Action: It works by enhancing the activity of antithrombin III, which primarily inhibits clotting factor Xa to prevent blood clot formation.
Key Indications: Clexane is used to prevent and treat deep vein thrombosis (DVT), pulmonary embolism (PE), and to manage certain heart conditions like unstable angina.
Common Side Effects: The most common side effect is bleeding or bruising, especially at the injection site.
Administration: It is typically administered via a subcutaneous injection into the abdomen, and injection sites should be rotated.
Potential Interactions: Taking Clexane with other blood thinners, NSAIDs, or aspirin increases the risk of bleeding.
Epidural/Spinal Risk: It carries a significant risk of spinal hematoma if used with neuraxial anesthesia, potentially leading to paralysis.

What is Clexane (Enoxaparin)?

Clexane is an anticoagulant medication containing the active ingredient enoxaparin sodium. It is a type of low molecular weight heparin (LMWH), which is a modified version of unfractionated heparin with a more predictable and sustained anticoagulant effect. Clexane works by interrupting the blood clotting process to prevent new clots from forming or existing ones from enlarging. It is typically administered via a subcutaneous injection, into the fatty tissue just under the skin.

How Clexane Prevents Blood Clots

Clexane primarily works by enhancing the activity of a natural anticoagulant called antithrombin III. When Clexane binds to antithrombin III, it accelerates its ability to inactivate key clotting enzymes, particularly Factor Xa. By blocking Factor Xa, Clexane effectively disrupts the coagulation cascade and inhibits the formation of thrombin, a crucial enzyme for clot formation.

Medical Uses for Clexane

Clexane is a versatile medication with several important indications. A doctor will prescribe the dose and duration of treatment based on the specific condition being treated. Primary uses include preventing deep vein thrombosis (DVT) in surgical patients or those with restricted mobility, treating existing DVT and pulmonary embolism (PE), managing acute coronary syndromes with other medications, and preventing clots in kidney dialysis machines.

Side Effects and Risks

The most significant risk with Clexane is bleeding. Patients should watch for unusual bleeding and report it to their doctor. Common side effects include bruising, pain, redness, or swelling at the injection site, and anemia. Serious side effects requiring immediate medical attention include persistent bleeding, blood in stool or urine, severe headache or chest pain, neurological symptoms, or severe allergic reactions. There is a heightened risk of spinal hematoma with Clexane if receiving spinal or epidural anesthesia, which could cause paralysis. Timing of administration around these procedures is critical.

Clexane vs. Other Anticoagulants

Clexane (enoxaparin) is an LMWH. Here's a comparison with other common anticoagulants:


Feature	Clexane (Enoxaparin) - LMWH	Unfractionated Heparin (UFH)	Direct Oral Anticoagulants (DOACs)	Warfarin (Vitamin K Antagonist)
Mechanism	Primarily inhibits Factor Xa, less effect on thrombin.	Inhibits both Factor Xa and thrombin.	Directly inhibits a specific clotting factor (e.g., Factor Xa or thrombin).	Inhibits the synthesis of Vitamin K-dependent clotting factors.
Administration	Subcutaneous injection, once or twice daily.	Intravenous or subcutaneous injection, often requires continuous infusion.	Oral tablets, once or twice daily.	Oral tablets, once daily.
Monitoring	Minimal or no routine monitoring required for most patients.	Requires frequent lab monitoring (aPTT) to adjust dose.	No routine lab monitoring required.	Requires frequent lab monitoring (INR) to adjust dose.
Onset of Action	Rapid, within hours.	Very rapid, almost immediate.	Rapid, within a few hours.	Slow, can take several days to reach full effect.
Cost	Can be more expensive than UFH or generic warfarin, but cost-effective compared to other options.	Generally inexpensive.	Can be expensive, though sometimes more cost-effective overall due to reduced monitoring.	Inexpensive.
Reversal Agent	Protamine sulfate.	Protamine sulfate.	Specific reversal agents are available, but not for all DOACs.	Vitamin K, fresh frozen plasma.

Important Considerations for Patients

Patients prescribed Clexane must follow instructions carefully. Injections are typically given into the abdominal wall, rotating sites to prevent bruising. The air bubble in the syringe should not be expelled. Certain medications, including aspirin, NSAIDs, and other anticoagulants, can increase bleeding risk with Clexane. Always inform your doctor about all medications and supplements. Monitoring may be needed for some patients, and the full prescribed course should be completed. You can find more information on the MedlinePlus drug information page for enoxaparin.

Conclusion

Clexane (enoxaparin) is an important anticoagulant used to prevent and treat blood clots. While its predictable action offers advantages, the risk of bleeding necessitates careful administration and awareness of potential side effects and interactions. Adhering to instructions and communicating with healthcare providers is crucial for safe and effective use.

Frequently Asked Questions

Clexane is administered via a subcutaneous (under the skin) injection, usually into the fatty tissue of the abdomen. The injection site should be rotated to prevent bruising and irritation.

Clexane acts quickly and is given by injection, whereas warfarin is an oral medication that works more slowly, taking several days to become fully effective. Warfarin also requires regular blood test monitoring (INR), while Clexane generally does not for most patients.

If you miss a dose, inject it as soon as you remember. However, if it is almost time for your next scheduled dose, skip the missed dose and continue your regular dosing schedule. Do not inject a double dose to compensate.

No, you should not take over-the-counter anti-inflammatory drugs (NSAIDs) like ibuprofen or naproxen, or products containing aspirin, while on Clexane without consulting your doctor, as this can increase your risk of bleeding.

Clexane pre-filled syringes should be stored at room temperature, away from heat and moisture. It should not be frozen. Check the packaging for specific storage instructions.

Contact a doctor immediately if you experience unusual bleeding or bruising, black or tarry stools, red or dark brown urine, prolonged bleeding from cuts, or vomiting blood.

Clexane can be used during pregnancy under a doctor's supervision. However, its use in pregnant patients with mechanical heart valves may be associated with increased risk of clots. Your doctor will weigh the benefits and risks based on your specific circumstances.