Page 182 - The Welfare of Cattle

PaIn MItIGatIon In CattLe 159

United States—an injectable formulation and a pour-on formulation for transdermal absorption.
Currently, injectable flunixin is indicated for the control of fever associated with respiratory disease
or mastitis, and fever and inflammation associated with endotoxemia. The transdermal flunixin is
indicated for the control of fever associated with respiratory disease and the control of pain associ-
ated with foot rot. Flunixin has been shown to have age-related pharmacokinetics for both the IV
injectable and transdermal routes. 8

Ketoprofen

Ketoprofen is an NSAID of the propionic acid class. It has approval as an adjunctive therapy
for fever, pain, and inflammation associated with mastitis and inflammatory and painful condi-
9
tions of bones and joints lass of NSAIDs in the European Union and Canada. Ketoprofen is
administered as a racemic mixture (50:50) with chiral RS± enantiomers. Interestingly, the R(−)
enantiomer will undergo chiral inversion to S(+) which is clinically relevant since the S(+) enan-
tiomer is a more potent PGE inhibitor. Ketoprofen has a relatively short half-life due to rapid
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2
metabolism and elimination, efforts to sustain analgesia may require multiple doses. Nevertheless,
many studies have investigated the analgesic potential of ketoprofen largely due to its approvals
in the EU and Canada.
Carprofen

Carprofen, like ketoprofen, is an NSAID in the propionic acid class. Carprofen is also adminis-
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tered as a racemic (50:50) mixture of RS± enantiomers. However, carprofen is not known to undergo
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chiral inversion. For cattle in the European Union, carprofen is indicated as an adjunct to antimi-
crobial therapy associated with respiratory disease and mastitis.
Unique pharmacokinetic properties of carprofen in cattle include a prolonged half-life, slow
clearance, and possibly biliary drug secretion as observed in dogs. Like flunixin meglumine, the
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pharmacokinetics of carprofen are age-dependent, with a prolonged half-life in younger animals
(<10 weeks), most likely due to the decreased clearance common to neonates. 12

Meloxicam

Meloxicam is a member of the oxicam class of NSAIDs. It has approval for use in the European
Union and Canada for adjunctive therapy of acute respiratory disease, diarrhea, acute mastitis, and
as an analgesic to relieve pain following dehorning in calves. In the United States, meloxicam is
approved to control pain associated with osteoarthritis in humans, dogs, and cats. The pharma-
cokinetics of meloxicam in cattle indicates a prolonged half-life and a high bioavailability when
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administered orally. Due to these favorable properties for providing practical analgesia in cattle,
many studies have recently investigated oral meloxicam as an analgesic.

Firocoxib

Firocoxib is an NSAID of the coxib class. This is a newer group of NSAIDs demonstrating
COX-2 selectivity in dogs and horses, thereby potentially limiting adverse effects caused by COX-1
inhibition. Currently, firocoxib is indicated for the treatment of pain and inflammation associated
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with osteoarthritis for dogs and horses in the United States. Limited information is available about
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firocoxib in cattle, with only one study conducted in preweaned calves. Unique pharmacokinetic
properties in preweaned calves include high oral bioavailability, prolonged terminal half-life, and
an extensive tissue distribution (high volume of distribution).