Interferon Alfa, Human Recombinant

What is interferon alfa, human recombinant?

Interferon alfa, human recombinant, is an immunomodulator used to treat virus-induced diseases in cats and dogs. It is used for both its anti-viral and immunomodulatory effects.

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 very carefully, as they may be significantly different from those on the label.

How do I give my pet interferon alfa, human recombinant?

• Interferon alfa, human recombinant, comes in an injectable liquid form.
• Injections are given subcutaneously (under the skin). The injectable form may also be given orally (by mouth). Follow your veterinarian’s directions.
• Measure liquids carefully.
• Dispose of used sharps in a designated sharps 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 may take several doses for effects to be seen.

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?

Interferon alfa, human recombinant, may cause the following side effects:

• Redness, mild pain, or swelling at injection site

Serious adverse reactions may occur. If any of the following signs develop, stop giving interferon alfa, human recombinant, and contact your veterinarian immediately:

• An allergic reaction such as irregular breathing, rash, fever, puffiness and swelling around the face
• Fever, weakness, body aches

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 should stop working within a few days, though effects may be prolonged in animals with kidney and/or liver disease.

Are there any risk factors for this medication?

DO NOT USE interferon alfa, human recombinant, in:

• Animals that are allergic to any component

USE WITH CAUTION in:

• Animals with a pre-existing autoimmune disease
• Animals with liver and/or kidney disease
• Animals with severe cardiac disease
• Animals that have any signs of neurological disease

Are there any drug interactions I should be aware of?

The following medications should be used with caution when given with interferon alfa, human recombinant:

• Antiviral drugs (e.g., acyclovir)
• Colchicine
• Theophylline

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?

• Baseline complete blood count (CBC) and thyroid function blood tests are required.
• Follow your veterinarian’s directions for lab work monitoring during treatment.
• 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 interferon alfa, human recombinant?

• Store the medication in the refrigerator.
• Protect from freezing and sunlight.
• Do not shake solution.
• 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.