Rivaroxaban

What is rivaroxaban?

Rivaroxaban is an anticoagulant (blood thinner) used to prevent or treat blood clots in cats and dogs.

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 rivaroxaban?

• Rivaroxaban comes in tablet form.
• Tablets are given orally (by mouth). 
• This medication may be given with food or on an empty stomach. 
• If your animal vomits or acts sick after receiving the drug on an empty stomach, try giving the next dose with a small amount of food or a small treat. If vomiting continues, contact your veterinarian.
• 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?

Contact your veterinarian for further direction if you miss giving a dose. This medication must be dosed carefully: do not give the pet two doses at once or change the dose.

Are there any potential side effects from rivaroxaban?

Rivaroxaban may cause the following side effects:

• Nausea, vomiting
• Itchiness and/or skin rash
• Diarrhea

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

• Bleeding, bruising, collapse, pale gums
• Extreme weakness, difficulty breathing
• 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 short-acting medication 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 rivaroxaban in pets who:

• Are allergic to any component of the medication
• Have uncontrolled bleeding
• Have severe liver and/or kidney disease

USE WITH CAUTION in pets who:

• Have a history of bleeding or clotting disorders
• Have liver and/or kidney disease
• May have surgery within 24 hours of getting the medication

Are there any drug interactions I should be aware of?

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

• Antiplatelet medications (e.g., clopidogrel)
• Azole antifungals (e.g., ketoconazole)
• CYP3A4 inducers (e.g., rifampin, phenobarbital)
• Fluoxetine
• Macrolide antibiotics (e.g., clarithromycin, erythromycin)
• NSAIDs (e.g., carprofen, meloxicam)
• Other anticoagulants (e.g., heparin, warfarin)

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 clotting times, a complete blood count (CBC), and baseline kidney and liver function blood work 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 rivaroxaban?

• Store at room temperature of 59°F-86°F (15°C-30°C) in a tightly closed container.
• 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.