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Molidustat

What is molidustat?

Molidustat (brand name Varenzin™-CA1) is a medication used to treat anemia (low number of red blood cells) in cats with chronic kidney disease. Molidustat helps increase red blood cell production. It is conditionally approved for use in cats only.

How do I give my pet molidustat?

  • Molidustat comes in liquid suspension form.
  • Liquids are given orally (by mouth).
  • You can give this medication with or without food. 
  • If vomiting occurs when dosed on an empty stomach, give future doses with food or a treat.  If vomiting continues, contact your veterinarian.
  • Shake the bottle well prior to measuring out the dose.
  • Give this medication directly into your cat’s mouth using the provided syringe – do not place it in food.
  • Give this medication to your pet for the entire time prescribed by your veterinarian, even if it appears your pet is feeling better.

This medication may take several days to start working. 

What if I miss giving my pet the medication?

If you miss a dose, give it as soon as you remember, and then continue with the regular dosing schedule. However, if it is almost time for the next dose, skip the missed dose and resume the regular dosing schedule. Do not give the pet two doses at once.

Are there any potential side effects from molidustat?

Molidustat may cause the following side effects:

  • Vomiting

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

  • An allergic reaction such as irregular breathing, rash, fever, puffiness and swelling around the face
  • Changes in gum color
  • Fast heart rate
  • Seizures

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 moderate-acting medication should stop working within several days, although effects can be longer in pets with liver or kidney disease.

Are there any risk factors for this medication?

DO NOT USE molidustat in cats that:

  • Have known allergies to any component of the medication
  • Are breeding, pregnant, or nursing

USE WITH CAUTION in cats that:

  • Are less than one year old
  • Have a known history of seizures
  • Have a known risk of blood clot formation

Are there any drug interactions I should be aware of?

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

  • Oral medications that contain aluminum, calcium, iron, zinc and/or magnesium
  • Phosphate-binding agents (e.g., lanthanum, sevelamer)
  • Erythropoiesis-stimulating agents (e.g., darbopoetin)

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 will check red blood cell levels (HCT or PCV) before starting this medication, during treatment, and after stopping this medication. Follow your veterinarian’s recommendation on frequency of testing.
  • Your veterinarian will let you know when and how they want to reassess your pet to ensure the medication is working and not causing side effects.
  • At home, monitor for any side effects such as those noted above. If any occur, stop using the medication and contact your veterinarian.

How do I store molidustat?

  • Store at room temperature in original 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. Be prepared to provide information about the product and your pet's weight and symptoms. 

© Copyright 2025 LifeLearn Inc. Used and/or modified with permission under license. This content written by LifeLearn Animal Health (LifeLearn Inc.) is licensed to this practice for the personal use of our clients. Any copying, printing or further distribution is prohibited without the express written consent of LifeLearn. This content does not contain all available information for any referenced medications and has not been reviewed by the FDA Center for Veterinary Medicine, or Health Canada Veterinary Drugs Directorate. This content may help answer commonly asked questions, but is not a substitute for medical advice, or a proper consultation and/or clinical examination of your pet by a veterinarian. Please contact your veterinarian if you have any questions or concerns about your pet’s health. Last updated on May 27, 2025.