Darbepoetin Alfa

What is darbepoetin alfa?

Darbepoetin alfa is a medication that is prescribed off-label to treat low red blood cell levels (anemia) caused by progressing kidney disease in dogs and cats. There are no veterinary brands of darbepoetin alfa.

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 darbepoetin alfa?

• Darbepoetin alfa comes as a clear, colorless, liquid solution that is injected under the skin.
• Your veterinary team can teach you how to give your pet injections at home. Be sure you understand how to draw the correct amount of solution into the syringe and the proper places and technique for the injections.
• Use a new needle and syringe each time you give an injection (shot) or mix a vial. Do not reuse needles and syringes.
• If you inject this medication at home, place used needles and syringes in a sharps disposal container immediately after they are used. Your veterinarian or pharmacist will help you obtain these containers.
• Do not disconnect the needle from the syringe.
• If you have difficulty getting your pet to accept the injections, contact your veterinarian for tips to help with dosing and reducing the stress of medication time.

This medication takes several doses before you will see any effect and the medication’s full effects may not be evident until your animal has taken it consistently for several weeks. Effects may not be noted outwardly, and laboratory tests may be needed to evaluate this medication’s effectiveness.

What if I miss giving my pet the medication?

If you miss a dose of darbepoetin alfa, 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 darbepoetin alfa?

Darbepoetin alfa may cause the following side effects:

• Stinging sensation or pain at the injection site
• Diarrhea
• Vomiting

Serious adverse reactions associated with this drug may occur without warning and could, in rare cases, lead to death. If any of the following signs develop, stop giving darbepoetin alfa and contact your veterinarian immediately:

• Low energy level
• Collapse
• Seizures (convulsions)
• Fever
• Joint pain
• Mouth ulcers
• No appetite
• High blood pressure
• Skin reactions at the site where the drug is injected (may indicate your pet’s body is creating antibodies to darbepoetin, which means it will not work effectively)

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 and notify your veterinarian if you have any concerns.

Other side effects may occur. If you notice anything unusual, contact your veterinarian immediately. This moderate-acting medication should stop working within a few days, although effects may be longer in pets with liver or kidney disease.

Are there any risk factors for this medication?

DO NOT USE darbepoetin alfa in:

• Pets that are allergic to it or have had adverse reactions to it previously (development of antibodies)
• Pets with uncontrolled high blood pressure

USE WITH CAUTION in:

• Pets with moderate to severe high blood pressure
• Pets with iron deficiency

Are there any drug interactions I should be aware of?

Several medications should be USED WITH CAUTION when given with darbepoetin alfa, including:

• Cyclosporine
• Testosterone, danazol, and other androgen drugs
• Probenecid 
• Spironolactone, benazepril

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

Is any monitoring needed with this medication?

• A packed cell volume (PCV) test, which indicates the degree of anemia, should be done before each dose of darbepoetin or until your veterinarian agrees that your pet’s PCV is stable.
• Other blood tests are recommended on a routine basis to assess red blood cells and iron levels.
• Blood pressure should be measured at regular intervals.
• Your veterinarian will let you know when 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 side effects occur, discontinue use of the medication, and contact your veterinarian. 

How do I store darbepoetin alfa?

• Store at 36°F to 46°F (2°C to 8°C). May be stored at room temperature for up to 7 days.
• Do not shake or freeze. Do not use product that has been shaken or frozen.
• Protect from light.
• Store in the original carton until use.
• Keep containers out of reach of children and animals.
• Dispose of needles and syringes safely, as directed by your veterinarian.

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.