Enoxaparin (Low Molecular Weight Heparin)

What is enoxaparin? 

Enoxaparin, also known as Low Molecular Weight Heparin or LMWH, is an anticoagulant (blood thinner) used to prevent or treat blood clots in cats, dogs, and horses. It may be used before surgery to prevent blood clot formation. 

It is used off label (extra label) in veterinary medicine. Many drugs are commonly prescribed for off-label use in veterinary medicine. “Off label” means the drug is being used in a way that has not been reviewed or approved by the U.S. Food and Drug Administration (FDA) or Health Canada. 

In these instances, follow your veterinarian’s directions and cautions carefully, as they may be significantly different from those on the label. 

How do I give my pet enoxaparin? 

• Enoxaparin comes in an injectable form. 
• Injections are given subcutaneously (under the skin).  
• Measure the amount of medication to be given very carefully – enoxaparin is a potent (strong) drug and doses are small and precise. 
• Use a new needle and syringe each time the medication is given. 
• Follow your veterinarian’s directions on how and where to give the injection. 
• Do not shake the vial. 
• Dispose of sharps in a designated sharps disposal container. 
• Give this medication to your pet for the entire time prescribed by your veterinarian, even if it appears that your pet is feeling better. 

This medication should take effect within 1 to 2 hours, though effects will not be noticed outwardly.  

What if I miss giving my pet the medication? 

• If you miss a dose, give it as soon as you remember, and then wait the recommended time as prescribed by your veterinarian for the next dose. 
• Contact your veterinarian for further directions if you are unsure about dosing or timing – this medication must be given carefully. 
• Do not give the pet two doses at once or change the dose. 

Are there any potential side effects from enoxaparin? 

Enoxaparin may cause the following side effects:

• Itchiness, pain, and/or redness at injection site 

The following reactions are rare, but if they occur, contact your veterinarian immediately: 

• Bleeding, bruising 
• Fever 
• An allergic reaction such as irregular breathing, rash, fever, puffiness and swelling around the face 

Drug sensitivities can develop over time with repeated exposure. Your pet may have no reaction after the first few doses, but may develop a sensitivity later. It is important to watch for signs of an allergic reaction over the entire course of treatment. 

Other side effects may occur. If you notice anything unusual, contact your veterinarian immediately. This medication is short-acting, meaning that effects will last less than 24 hours, though effects may last longer in pets with kidney or liver disease. 

Are there any risk factors for this medication? 

DO NOT USE enoxaparin in pets who: 

• Are allergic to any component of the medication (including pork products)  
• Are allergic to similar medications (e.g., heparin) 

USE WITH CAUTION in pets who: 

• Have a history of low platelets or other bleeding disorders 
• Have kidney disease 

Are there any drug interactions I should be aware of? 

Certain medications should be USED WITH CAUTION when given with enoxaparin, including:  

• Antiplatelet medications (e.g., clopidogrel) 
• NSAIDs (e.g., carprofen, meloxicam) 
• Other anticoagulants (e.g., warfarin) 
• SSRI antidepressants (e.g., fluoxetine) 
• Thrombolytic agents

Be sure to tell your veterinarian about any medications (including vitamins, supplements, or herbal therapies) that your pet is taking before starting any new treatment. 

Is any monitoring needed with this medication? 

• Your veterinarian may assess a complete blood count (CBC) before starting this medication. 
• Your veterinarian may schedule follow-up visits for monitoring. In this case, follow your veterinarian’s directions. 
• At home, monitor for any abnormal changes. If these occur, discontinue the medication and contact your veterinarian. 

How do I store enoxaparin?

• Store at room temperature of 77°F (25°C) with excursions of 59°F-86°F (15°C-30°C) permitted. 
• Follow manufacturer’s directions on expiration and discard times. 
• Keep medication out of reach of children and pets.

What should I do in case of emergency?

If you suspect an overdose or an adverse reaction to the medication, call your veterinary office immediately. If they are not available, follow their directions in contacting an emergency facility. Adverse effects should be reported to the FDA or Health Canada.