Brand Name: Deramaxx; Rederox

Available in 25 mg, 50 mg, 75 mg, and 100 mg chewable

Background

Deracoxib is a member of the class of drugs known as NSAIDs (non-steroidal anti-inflammatory drugs), the same class as such common over-the-counter remedies as Advil (Ibuprofen), Aleve (Naproxen), and aspirin. This class of drug is used for pain relief successfully in humans but the development of safe NSAIDs for pets has only been achieved relatively recently.

The problem with the pet use of NSAIDs made for humans has been unacceptable (even life-threatening) side effects:

• Stomach ulceration - even perforation and rupture of the stomach can occur. This is not only painful but life-threatening.
• Platelet deactivation—Platelets are the cells controlling the ability to clot blood, and it is preferable not to promote bleeding. It is also preferable that platelets remain active and able to function should they be needed. 
• Decreased blood supply to the kidney - this could tip a borderline patient into kidney failure.

The veterinary profession had been in need of an NSAID that could effectively relieve pain without the above risks, and, finally, a new class of pain reliever arose. This was made possible by new biochemical knowledge. Many of the biochemicals responsible for pain and inflammation are produced by an enzyme called cyclo-oxygenase 2, or simply COX-2. The goal is to inhibit this enzyme without inhibiting its counterpart, cyclo-oxygenase 1 (COX-1). Both COX enzymes produce prostaglandins, but the goal is to keep the ones from COX-1 that help maintain our bodies but not make the inflammatory prostaglandins that come from COX-2.

In the past, NSAIDs could not distinguish the COX enzymes and inhibited them both. With the development of COX preferential NSAIDs, COX-2 can be inhibited, and COX-1 largely left alone. The introduction of COX-2 preferential NSAIDs has reduced stomach and intestinal side effects by 50 percent in humans and has made FDA approval of certain NSAIDs possible for pets. The coxib class of NSAIDs takes things a step further. The coxib class is actually COX selective, not merely COX preferential, which means that at usual doses, it completely inhibits COX-2 and completely leaves COX-1 alone, potentially making a safer drug. Deracoxib is a member of the coxib class.

How this Medication is Used

Deracoxib is used to treat pain either for short-term or long-term use with different dosing schedules depending on how the drug is to be used. In addition to pain relief, deracoxib has been found to be helpful in suppressing bladder cancer (transitional cell carcinoma). This effect appears to be separate from its pain-relieving properties.

All NSAIDs, even the COX-2 selective ones, have some potential for reactions. Deracoxib would not be appropriate for a dog with kidney or liver disease, so screening tests are needed, and monitoring tests are recommended. A dog that is potentially a candidate for long-term use of deracoxib should have a complete examination by the veterinarian, a screening blood panel to establish baseline biochemical values, and, ideally, some kind of recheck testing two weeks after starting deracoxib. This is because most adverse reactions, unusual as they may be, occur within this initial time frame and it is important that they be recognized before they get out of hand. After this initial period, complete blood panels should be screened every six months, an important step with any medication for long-term use, not just the NSAIDs.

Deracoxib may be given with or without food. If a dose is accidentally skipped, do not double up on the next dose but instead give the dose when it is remembered and time the next dose accordingly. Deracoxib is given once daily.

Cats are more sensitive to NSAID side effects than dogs and require different pain relief regimens. This drug should not be used in cats.

Side Effects

Stomach upset: vomiting, diarrhea, and/or appetite loss are the important side effects to watch for, especially in the three weeks or so after beginning long-term deracoxib. These symptoms can have multiple meanings so it is important to sort them out.

• Some dogs are simply sensitive to NSAIDs, despite the COX-selective nature of deracoxib described above. These dogs simply need nausea relief in the short term and a different pain management regimen after recovery.
  
  
• Some dogs have an unrecognized liver problem. The liver removes deracoxib from the body, which means that the liver on deracoxib has extra work. This is not a problem for a normal liver, but a diseased liver could be tipped into failure from the extra load. This is why screening tests are so important prior to long-term use.
  
  
• Another problem manifesting with an upset stomach is an idiosyncratic hepatopathy (a liver condition that is not dose-dependent or predictable in any way). While this only occurs in 1 in 5000 dogs, it is a more serious problem that likely would require hospitalization.

If a dog on deracoxib develops an upset stomach, discontinue the medication and report the problem to your veterinarian. It is prudent to check liver enzymes (a blood test) to rule out the two liver side effect issues that could manifest with an upset stomach.

Other side effects typically require other pre-existing conditions that could be made worse by giving an NSAID, even a COX-selective one. See the Concerns and Cautions section.

Interactions

Multiple drugs of the NSAID class should not be used together as the potential for NSAID side effects increases. This means a greater chance of exactly what it was hoped to avoid by using a COX-selective NSAID instead of a non-selective NSAID: stomach irritation/ulceration, altered kidney function, and inappropriate bleeding. For similar reasons, NSAIDS should not be used in conjunction with corticosteroid hormones such as prednisone, dexamethasone, etc. A 5-7 day rest period is recommended when changing over to deracoxib from another NSAID or vice versa. Aspirin poses an exception due to its strong platelet inactivating abilities, so 10 to 14 days is recommended when switching to carprofen from aspirin. Allow at least one week between prednisone and deracoxib.

If deracoxib is used concurrently with phenobarbital, it is especially important that appropriate liver monitoring be performed. (I recommend bile acids testing every six months for dogs on phenobarbital.) These two drugs interact such that neither may work well if they are used together.

ACE inhibitors such as enalapril or benazapril may not be as effective in the presence of NSAIDs. (ACE inhibitors are used in the treatment of hypertension or heart failure.) This is because ACE inhibitors depend on the dilation of blood vessels in the kidneys, and such dilation can be interfered with by NSAIDs).

Concerns and Cautions

Deracoxib is available as a chewable tablet which is highly palatable to animals. This increases the potential for accidental overdose should a pet gain access to a large amount of chewable tablets.

Keep chewable deracoxib out of the reach of children and pets.

Deracoxib has not been tested in pregnant or nursing females and thus is not recommended for use in such individuals, particularly since COX-2 is important in reproductive function. 

NSAIDs should not be used in dogs with pre-existing liver or kidney disease. In order to screen for pre-existing liver or kidney disease, it is a good idea to run a blood chemistry panel prior to starting long-term therapy with an NSAID.

The blood pressure-related side effects that have made COX-2 selective NSAIDs controversial in humans are not significant factors in canine use.

Deracoxib should not be used in patients with pre-existing GI ulcerations.

Deracoxib has been tested for safety in puppies as young as four months of age but not younger. Safety has not been evaluated in younger puppies.

Read the product insert and more information from the manufacturer.