NSAID (nonsteroidal anti-inflammatory drug)

What Is An NSAID?

An NSAID, or nonsteroidal anti-inflammatory drug, is a medication that relieves pain, relieves fever, and relieves inflammation.

What are examples of diseases NSAIDs are used for in pets?

Nonsteroidal anti-inflammatory drugs are used for arthritis, inflammation in the eye (anterior uveitis), knee ligament injury (cruciate disease), hip and elbow dysplasia, knee cap dislocation (patellar dislocation), rheumatoid or septic arthritis, abnormal joint cartilage development (osteochondritis dissecans or OCD), spinal arthritis (spondylosis deformans), and cancer pain.

How do NSAIDs work? Nonsteroidal anti-inflammatory drugs work by blocking production of prostaglandin molecules that promote pain. NSAIDs revive the spirits of pets by resolving pain, allowing them to exercise so that the heart, lungs, and gut all function normally. With exercise, pets maintain their muscles, and this helps them hold their joints in correct alignment, another reason they experience less pain.

Making NSAID use safer

1. Use NSAIDs with chondroprotectives like Glyco-Flex, and with Omega 3 Fatty Acids like Lipiderm to reduce the amount, or the frequency, of NSAID use.

2. Never give NSAIDs without your veterinarian's advice. Dogs and cats can be killed by the wrong medication, or the right medication given too often. Since the NSAID Ibuprofen was released as an over-the-counter tablet, it has generated more calls to the National Animal Poison Control Center by dog and cat owners than has any other single drug.

3. Without specific instructions from your veterinarian, don't give NSAIDs to cats.

4. Don't use two NSAIDs at the same time unless specifically instructed to do so.

5. Don't use an NSAID and a steroid at the same time unless specifically instructed to do so.

6. Do the lab tests for your pet as requested by your veterinarian.

7. Check the pet's stool for the presence of blood. Pets on NSAIDs can develop stomach and intestinal ulcers. Blood that leaks from an ulcer passes through the gut along with food and is digested into a black, tarry substance. Finding a blackish stool, or a stool that looks like it contains coffee grounds, is reason to stop medicating with NSAIDs and notify your veterinarian immediately.

8. Store the medication out of reach of children and pets. Considering the ingenuity of cats, kids, and puppies, you may need a locked cupboard. These medications are sometimes flavored, and pets go to great lengths to find and eat them.

What's a prostaglandin?

All the cells in the body are surrounded by membranes. One of the molecules found in cell membranes is arachadonic acid. Arachadonic acid can be modified to produce several different types of prostaglandins (PG) molecules, according to what the body needs. Prostaglandin molecules tend to have two functions: they either promote inflammation or promote normal cell function. The type of PG produced is determined by which enzyme modifies arachadonic acid. If the enzyme cyclooxygenase 1 (COX 1) transforms arachadonic acid, PG E1 prostaglandin is produced. If the enzyme cyclooxygenase 2 (COX 2) transforms arachadonic acid, PG E2 prostaglandin is produced.

Generally, prostaglandins of the E1 series work to promote normal function, including normal function of the stomach, liver, heart, and kidney. For example, in the stomach PG E1 helps maintain the mucus lining that protects the stomach from hydrochloric acid. In contrast, prostaglandins of the E2 series work to promote inflammation. Inflammation can be good when the body needs to attack diseases, such as cancer, feline leukemia, or canine parvo. But inflammation can also be bad—for example, when it causes the body to attack itself, as with an immune-mediated disease such as pemphigus, some thyroid diseases, rheumatoid arthritis, and lupus. Inflammation is also bad when it occurs to excess, and immune cells attack like a swarm of bees. This type of excessive inflammation can occur with wear-and-tear osteoarthritis, and with elbow or hip dysplasia.

Understanding prostaglandins and the COX enzymes that produce them allows us to understand how NSAIDs work. NSAIDs either target COX 1 enzymes and the PG they produce, COX 2 enzymes and the PG they produce, or both COX 1 and COX 2.

How do NSAIDs target prostaglandins?

NSAIDs are medications designed to target the COX enzymes that produce prostaglandins. Some of the newer NSAIDs are somewhat selective (Deramaxx (Rx)) and target COX 2 more than COX 1. An NSAID that targets COX 2 helps stop inflammation.

The older NSAIDs (aspirin and Rimadyl (Rx)) are less selective, targeting both COX 1 and COX 2, so they decrease beneficial stomach mucus at the same time that they decrease inflammation.

In actuality, no NSAID is completely selective for COX 1 or COX 2. This may be good because the latest research suggests the best pain relief may come from products that affect both COX 1 and COX 2.

What are potential side effects from NSAIDs?

About 1% of pets taking NSAIDs have a problem or side effect because of the drug. A common NSAID side effect is gastric ulcer. The pet may refuse to eat, vomit, and pass dark, tarry stool. Another side effect is kidney damage, causing the pet to drink more and urinate more, a condition called PUPD, or polydipsia, polyuria. Pets may become anemic with pale gums, or they may have yellow (icteric) gums. It is also common for NSAIDs to damage the liver. Fortunately, for most pets the organs return to normal when the NSAID is withdrawn.

In humans, some COX 2 inhibitors affected prostaglandins that protected the heart so that some people taking these drugs suffered heart attacks. Pets don't have the same predisposition to heart attack as humans do, but research has not clarified the full effect COX 2-inhibiting NSAIDs will have on pet hearts.

Can I use human NSAID for my pet?

Medications for people, including NSAIDs, don't necessarily act the same in pets as they do in people. It is never wise to use them without specific veterinary instruction.

Can I use human aspirin for my pet?

Medications for people, including aspirin, don't necessarily act the same in pets as they do in people. Humans often take enteric-coated aspirin, but it is unwise to use these tablets in pets. Enteric coating prevents aspirin from dissolving easily so that it can sit in the pet's stomach for a long time. It's possible for aspirin to "collect" in the stomach, exposing the pet to a toxic dose. It's better to use aspirin, like Vetrin, specifically developed for pets, or to use a powdery, uncoated aspirin that dissolves easily. It's never wise to use aspirin without specific veterinary instruction.

What do we know about Rimadyl and the liver?

Veterinarians diagnose the liver toxicity with blood tests, and they find that the majority of these dogs make a full recovery after stopping the medication. Some dogs, however, can die or need to be euthanized because of liver damage. To protect a Labrador retriever, or any breed dog, from needing NSAIDs for arthritis pain, keep its weight down, and start it on cartilage-protecting supplements when it's young. We recommend Adequan (Rx), Legend (Rx), Glyco-Flex, 1-800-PetMeds Super Joint Enhancer and Missing Link with glucosamine.

What Do We Know About Piroxicam (Feldene) And Cancer?

A new use for the NSAID piroxicam is treating cancer of the mouth (squamous cell carcinoma) and of the bladder (transitional cell carcinoma).