Brand Name: Feldene

Available in 10 mg and 20 mg capsules

Background

The need for non-steroidal anti-inflammatory drugs (NSAIDS) in human medicine is profound. There is a plethora of products, both over the counter for routine aches and pains (aspirin, ibuprofen, ketoprofen etc.) and stronger prescription products (celecoxib, rofecoxib etc.) Piroxicam is one of the prescription NSAIDS for human use.

Arthritis pain is an important cause of loss of mobility in dogs as it is in humans. Before there were NSAIDs available for dogs, human medications were used. Aspirin was the most commonly used medication during that time but when aspirin was not effective there were few alternatives. Piroxicam was sometimes used for such cases though now there are numerous much safer products for canine arthritis pain.

Piroxicam might have completely faded into obsolescence were it not for the discovery that this medication has anti-tumor effects against certain types of carcinomas. Questions persist as to how piroxicam is able to suppress such tumors and currently it is believed that this effect relates to immune system related effects rather than direct action against the tumor cells.

How this Medication is Used

The transitional cell carcinoma of the urinary bladder is the most common target of this medication, although it is also used against mammary adenocarcinoma and squamous cell carcinoma.

Piroxicam is typically given once a day or every other day. It is best given with food. If a dose is accidentally skipped, it should be given when it is remembered and the next dose timed accordingly. Because the therapeutic range of piroxicam is narrow, it is important not to give extra medication or double up on missed doses as toxicity can result.

Interactions with other Drugs

Piroxicam should not be used in combination with other NSAIDs nor with steroids. The use of more than one anti-inflammatory in this way increases the potential for dangerous side effects, especially ulceration of the stomach and kidney failure.

The use of piroxicam reduces the necessary dose of the chemotherapeutic medication methotrexate. This sounds like a good thing but it will increase the potential for toxicity of methotrexate unless the dose is adjusted accordingly.

Piroxicam enhances the activity of vinblastine, an anticancer medication.

Piroxicam can exacerbate the renal toxicity properties of cisplatin. Concurrent use with bisphosphonides, as might occur with osteosarcoma, greatly increases the tendency for the stomach to get ulcers.

Piroxicam can increase the risk of bleeding if combined with clopidogrel, an anticoagulant. There can also be an increased risk of bleeding when piroxicam is combined with serotonin reuptake inhibitors or tricyclic antidepressants (used for behavior issues) such as fluoxetine, clomipramine, amitriptyline.

The risk of cyclosporine toxicity is raised if cyclosporine and piroxicam are used together.

Side Effects

The most common side effects of piroxicam are related to upset stomach and show as vomiting. Approximately, 15-20% of cats on piroxicam will experience vomiting. This is usually controlled by providing food with the medication.

More serious side effects are stomach/intestinal ulceration (which might be seen with black diarrhea, appetite loss or vomiting especially black or dark material). These signs create a challenge in evaluating the seriousness of upset stomach side effects. Other serious side effects include kidney insufficiency (increased thirst would be a potential sign of this) and prolonged bleeding.

Concerns and Cautions

Piroxicam should be stored so as to protect it from light exposure.

Vomiting or diarrhea may indicate that GI ulceration has occurred. If either of these symptoms is noted, discontinue the medication and contact your veterinarian promptly.

This medication is usually given once a day or every other day.

Some blood test monitoring may be recommended with long-term use.

It is our policy not to give dosing information over the Internet.