Varenzin-CA1: Product Information

VARENZIN-CA1- molidustat sodium suspension
Elanco US Inc.



(molidustat oral suspension)

Hypoxia-inducible factor prolyl hydroxylase (HIF-PH) inhibitor

25 mg/mL

For oral use in cats only

Conditionally approved by FDA pending a full demonstration of effectiveness under application number 141-571. It is a violation of Federal law to use this product other than as directed in the labeling.

Federal law restricts this drug to use by or on the order of a licensed veterinarian.


Varenzin-CA1 (molidustat oral suspension) is a white to yellow-white oily suspension. Each mL of Varenzin-CA1 contains 25 mg of molidustat sodium. The inactive ingredients are glycerol dibehenate, fish oil, sunflower oil, butylhydroxytoluene, and sorbic acid. The empirical formula is C13 H13 N8 O2 Na and the molecular weight is 336.28. The chemical name is Sodium 1-[6-(morpholin-4-yl)pyrimidin-4-yl]-4-(1H-1,2,3-triazol-1-yl)-1H-pyrazol-5-olate. The chemical structure of molidustat sodium is:

Chemical Structure
(click image for full-size original)


Varenzin-CA1 is indicated for the control of nonregenerative anemia associated with chronic kidney disease (CKD) in cats.


Shake well before use.

The dosage of Varenzin-CA1 is 2.3 mg/lb (5 mg/kg) body weight (bw) administered orally once daily for up to 28 consecutive days. Treatment may be repeated after a minimum 7-day pause (see Monitoring and Repeating Treatment). Varenzin-CA1 should be administered using the dosing syringe provided in the package. The dosing syringe is marked in increments of 0.1 mL. The dose should be rounded up to the nearest 0.1 mL.

Dosing Information

To ensure the correct dose is administered, body weight should be determined prior to starting treatment.

Table 1. Dosing Chart

Weight Range in

pounds (lb)

Volume of

Varenzin-CA1 (mL)

3.4 to 4.4


4.5 to 5.5


5.6 to 6.6


6.7 to 7.7


7.8 to 8.8


8.9 to 9.9


10 to 11


11.1 to 12.1


12.2 to 13.2


Note: The syringe included with the Varenzin-CA1 product cannot be used to accurately dose cats weighing under 3.4 pounds. Cats greater than 13.2 lb bw should be treated with a dose of 2.3 mg/lb bw rounded up to the nearest 0.1 mL.


Shake well before use. Remove screw cap. Use the enclosed syringe for each treatment. Place the syringe nozzle firmly into the opening of the bottle. Turn the bottle upside down and withdraw the necessary volume. Turn the bottle back into an upright position before removing the syringe. The product should be administered with the syringe into the cat’s mouth. See illustrations 1 through 4 below for administration steps:

Administration Steps
(click image for full-size original)

After administration, close bottle tightly with cap and store syringe in the carton together with the product. Do not disassemble or wash the syringe.

The product should be given once daily for up to 28 consecutive days. If the cat vomits after consuming any portion of the dose, the cat should not be re-dosed and should be considered as dosed for the day.

Monitoring and Repeating Treatment

Treated cats should initially have their hematocrit (HCT) or packed cell volume (PCV) levels monitored weekly beginning about the 14th day of the 28-day treatment cycle to ensure HCT or PCV does not exceed the upper limit of the reference range. Discontinue Varenzin-CA1 if HCT or PCV exceeds the upper limit of the reference range.

After treatment cessation the hematocrit level should be periodically checked (for example, weekly, every 2 weeks or monthly). When the HCT or PCV level declines below the lower limit of the reference range, a new treatment cycle should be started. The interval between treatment cycles will vary between cats and may change over time for an individual cat but should be at least 7 days.

If a cat does not respond to treatment after 3 weeks (see REASONABLE EXPECTATION OF EFFECTIVENESS), it is recommended to re-examine the animal for any other underlying condition that may contribute to anemia, such as iron deficiency, inflammatory diseases or blood loss. It is advised to treat the underlying condition before restarting treatment with Varenzin-CA1.


Varenzin-CA1 should not be administered to cats with known hypersensitivity to molidustat or to any of the inactive ingredients.

Varenzin-CA1 should not be administered to cats that are pregnant, lactating, or intended for breeding. In an embryo-fetal-developmental toxicity study in rats, an increase incidence of ocular malformations such as flat eye rudiments and microphthalmia were observed at doses of 30 mg/kg bw per day. These effects may be due to an increase in oxygen availability, caused by molidustat-induced polycythemia. Localized hypoxia is an important factor in normal eye development. Developmental toxicity studies have not been conducted in cats. Available animal data have shown excretion of other HIF-PH inhibitors into milk. It is unknown whether molidustat is excreted into the milk of lactating cats.


User Safety Warnings

Not for use in humans.

Keep this drug, including used syringes, out of reach of children. Wash hands immediately after use and/or spillage.

In case of accidental ingestion, seek medical advice immediately and show the package leaflet or the label to the physician. Symptoms of exposure to molidustat may include the following: gastrointestinal effects (nausea, vomiting, diarrhea), blood and clotting effects (increases in reticulocytes, erythropoietin, and hemoglobin), dizziness, fainting, hypertension, changes in cardiac output and cardiac index, and increases in heart rate.

Symptoms may not occur immediately; therefore, the exposed individual should be monitored. People with known hypersensitivity to molidustat sodium should avoid direct contact with this product and should administer the product with caution.

Women who are pregnant or may become pregnant should administer the product with caution. Molidustat administered orally to pregnant rats during the period of organogenesis was associated with adverse fetal outcomes (see CONTRAINDICATIONS).

Do not eat, drink, or smoke while handling this product.

Animal Safety Warnings

Keep Varenzin-CA1 in a secure location out of reach of dogs, cats, and other animals to prevent accidental ingestion or overdose.

Page 1 of 3 1 2 3 provides trustworthy package insert and label information about marketed drugs as submitted by manufacturers to the U.S. Food and Drug Administration. Package information is not reviewed or updated separately by Every individual animal healthcare product label entry contains a unique identifier which can be used to secure further details directly from the U.S. National Institutes of Health and/or the FDA.

Our database mirrors the FDA's central repository of drug labels and package inserts under the Structured Product Labeling standard. provides the full animal health subset of the FDA's repository. Veterinary information provided here is not intended as a substitute for direct consultation with a qualified veterinary professional.

Terms of Use | Copyright © 2023. All Rights Reserved.