Brand Name: Apoquel

Available as 3.6 mg, 5.4 mg, 16 mg tablets

Background

Diseases causing itchy skin abound in dogs. Rashes, hot spots, smelly yeast infections, seemingly endless chewing and scratching all contribute to reduced life quality for dogs as well as a barrier to the human-animal bond when people are reluctant to snuggle a stinky, itchy pet. Assorted shampoos, steroid-based sprays and ointments, injections and more have been available for decades. The JAK (Janus Kinase) inhibitors represent a new way to address itching.

Most people are not familiar with the term cytokine. A cytokine is a chemical released by a cell to message another cell. The message can be stimulatory or inhibitory and one cell releases a cytokine message may communicate its command to many other cells. Some cytokines act to stimulate the Janus Kinase enzymes, of which there are several. Janus Kinase-1 and Janus Kinase-3 trigger production of cytokines involved in inflammation and the perception of itch (at least in dogs). JAK inhibitors have been found useful in several inflammatory conditions and have applications beyond simply itch control in allergy. New uses in skin disease are constantly being discovered.

How this Medication Is Used 

Oclacitinib maleate is used twice daily for two weeks and then dropped to a maintenance dose of once daily. It generally reduces itching very quickly — within 24 hours — and is felt to be as effective as corticosteroids, such as prednisolone. 

It does not have a dramatic effect in every patient and some patients need more itch control. In this situation, it is best to use a second medication or treatment rather than returning to twice daily oclacitinib maleate or increasing the dose. See more options for itch control.

The presence of infection readily dampens the effect of oclacitinib so it is important to address concurrent skin infections in order to maximize the effectiveness of oclacitinib.

Oclacitinib maleate may be given with or without food. It is not recommended for dogs under the age of one, nor for pregnant/lactating mothers. While it is not approved for use in cats, it has been used with success in cats. 

Oclacitinib maleate should be stored at room temperature, protected from light. 

If a dose is accidentally skipped, give it when it is remembered and time the next dose accordingly. Do not double up on dosing.

Side Effects 

There are several caveats to the use of oclacitinib maleate. 

1. This medication is meant to control the symptoms of itching. For many patients, ending itching also ends scratching and chewing. Ending scratching and chewing ends infections and a vicious cycle can finally be broken. The problem is that while oclacitinib maleate can control itching, it may not control the disease that is causing the itching. If there is an infection, it will still be there; it just won’t be as itchy. It is important not to let skin disease persist simply because the dog is comfortable. The disease must be controlled as well.

2. The oclacitinib maleate label contains a caution against use in patients with cancer. While oclacitinib maleate does not cause cancer, there is question about whether it can interfere with natural protective mechanisms that help control cancer. If a patient is known to have cancer or an undefined growth on its body, or if there is any reason to suspect a patient might be harboring cancer, it is important to discuss this caution with your veterinarian before using this.

3. Oclacitinib maleate appears to promote or support Demodex skin mites. It should not be used to control itching associated with Demodectic mange. 

4. Oclacitinib use could reactivate an old Demodectic mange infection.
The most common side effects of oclacitinib maleate are vomiting, diarrhea, appetite loss and listlessness. These signs are generally mild, temporary and/or controllable by giving food with the medication.

Interactions With Other Drugs 

Both oclacitinib maleate and cyclosporine are used to control itching but their mechanisms are not compatible for long-term use (greater than 3 weeks) together.

Concerns and Cautions 

Oclacitinib maleate should not be used in patients with a history of cancer, severe infection, or demodectic mange. Any new skin growths should be reported to the veterinarian promptly.

Monitoring lab work is commonly recommended for any medication in use longer than six months. Many veterinarians recommend baseline blood testing before beginning therapy with oclacitinib.