Rimadyl Injection

Federal law restricts this drug to use by or on the order of a licensed veterinarian.

Carprofen is a non-narcotic, nonsteroidal anti-inflammatory agent with characteristic analgesic and antipyretic activity approximately equipotent to indomethacin in animal models.1

The mechanism of action of carprofen, like that of other NSAIDs, is believed to be associated with the inhibition of cyclooxygenase activity. Two unique cyclooxygenases have been described in mammals.2 The constitutive cyclooxygenase, COX-1, synthesizes prostaglandins necessary for normal gastrointestinal and renal function. The inducible cyclooxygenase, COX-2, generates prostaglandins involved in inflammation. Inhibition of COX-1 is thought to be associated with gastrointestinal and renal toxicity while inhibition of COX-2 provides anti-inflammatory activity. The specificity of a particular NSAID for COX-2 versus COX-1 may vary from species to species.3 In an in vitro study using canine cell cultures, carprofen demonstrated selective inhibition of COX-2 versus COX-1.4 Clinical relevance of these data has not been shown. Carprofen has also been shown to inhibit the release of several prostaglandins in two inflammatory cell systems: rat polymorphonuclear leukocytes (PMN) and human rheumatoid synovial cells, indicating inhibition of acute (PMN system) and chronic (synovial cell system) inflammatory reactions.1

Several studies have demonstrated that carprofen has modulatory effects on both humoral and cellular immune responses.5–9 Data also indicate that carprofen inhibits the production of osteoclastactivating factor (OAF), PGE1, and PGE2 by its inhibitory effects on prostaglandin biosynthesis.1

Based upon comparison with data obtained from intravenous administration, carprofen is rapidly and nearly completely absorbed (more than 90% bioavailable) when administered orally.10 Peak blood plasma concentrations are achieved in 1–3 hours after oral administration of 1, 5, and 25 mg/kg to dogs.

The mean terminal half-life of carprofen is approximately 8 hours (range 4.5–9.8 hours) after single oral doses varying from 1–35 mg/kg of body weight. After a 100 mg single intravenous bolus dose, the mean elimination half-life was approximately 11.7 hours in the dog. Rimadyl is more than 99% bound to plasma protein and exhibits a very small volume of distribution.

Comparison of a single 25 mg dose in Beagle dogs after subcutaneous and oral administration demonstrated that the dorsoscapular subcutaneous administration results in a slower rate of drug input (as reflected by mean peak observed concentrations) but comparable total drug absorption within a 12 hour dosing interval (as reflected by area under the curve from hours zero to 12 postdose).

Carprofen is eliminated in the dog primarily by biotransformation in the liver followed by rapid excretion of the resulting metabolites (the ester glucuronide of carprofen and the ether glucuronides of 2 phenolic metabolites, 7-hydroxy carprofen and 8-hydroxy carprofen) in the feces (70–80%) and urine (10–20%). Some enterohepatic circulation of the drug is observed.

Keep out of reach of children. Not for human use. Consult a physician in cases of accidental human exposure. For use in dogs only. Do not use in cats.

All dogs should undergo a thorough history and physical examination before initiation of NSAID therapy. Appropriate laboratory tests to establish hematological and serum biochemical baseline data prior to, and periodically during, administration of any NSAID should be considered. Owners should be advised to observe for signs of potential drug toxicity (see Adverse Reactions, Animal Safety and Post-Approval Experience).

Carefully consider the potential benefits and risks of Rimadyl and other treatment options before deciding to use Rimadyl. Use the lowest effective dose for the shortest duration consistent with individual response. The recommended dosage for subcutaneous administration to dogs is 2 mg/lb (4.4 mg/kg) of body weight daily. The total daily dose may be administered as either 2 mg/lb of body weight once daily or divided and administered as 1 mg/lb (2.2 mg/kg) twice daily. For control of postoperative pain, administer approximately 2 hours before the procedure.

Confirmation of the effectiveness of Rimadyl for the relief of pain and inflammation associated with osteoarthritis, and for the control of postoperative pain associated with soft tissue and orthopedic surgeries was demonstrated in 7 placebo-controlled, masked studies examining the anti-inflammatory and analgesic effectiveness of Rimadyl caplets and injectable in various breeds of dogs.

Separate placebo-controlled, masked, multicenter field studies confirmed the anti-inflammatory and analgesic effectiveness of Rimadyl caplets when dosed at 2 mg/lb once daily or when divided and administered at 1 mg/lb twice daily. In these two field studies, dogs diagnosed with osteoarthritis showed statistically significant overall improvement based on lameness evaluations by the veterinarian and owner observations when administered Rimadyl at labeled doses.

Based upon the blood level comparison between subcutaneous and oral administration, Rimadyl effectiveness for osteoarthritis after dorsoscapular subcutaneous and oral administration should be similar, although there may be a slight delay in the onset of relief after subcutaneous injection.

Separate placebo-controlled, masked, multicenter field studies confirmed the effectiveness of Rimadyl injectable for the control of postoperative pain when dosed at 2 mg/lb once daily in various breeds of dogs. In these studies, dogs presented for ovariohysterectomy, cruciate repair and aural surgeries were administered Rimadyl preoperatively and for a maximum of 3 days (soft tissue) or 4 days (orthopedic) postoperatively. In general, dogs administered Rimadyl showed statistically significant improvement in pain scores compared to controls.

1. Baruth H, et al: In Anti-Inflammatory and Anti-Rheumatic Drugs, Vol. II, Newer Anti-Inflammatory Drugs, Rainsford KD, ed. CRC Press, Boca Raton, pp. 33–47, 1986.
2. Vane JR, Botting RM: Mechanism of action of anti-inflammatory drugs. Scand J Rheumatol 25:102, pp. 9–21.
3. Grossman CJ, Wiseman J, Lucas FS, et al: Inhibition of constitutive and inducible cyclooxygenase activity in human platelets and mononuclear cells by NSAIDs and COX-2 inhibitors. Inflammation Research 44:253–257, 1995.
4. Ricketts AP, Lundy KM, Seibel SB: Evaluation of selective inhibition of canine cyclooxgenase 1 and 2 by carprofen and other nonsteroidal anti-inflammatory drugs. Am J Vet Res 59:11, pp. 1441–1446, November 1998.
5. Ceuppens JL, et al: Non-steroidal anti-inflammatory agents inhibit the synthesis of IgM rheumatoid factor in vitro. Lancet 1:528, 1982.
6. Ceuppens JL, et al: Endogenous prostaglandin E2 enhances polyclonal immunoglobulin production by ionically inhibiting T suppressor cell activity. Cell Immunol 70:41, 1982.
7. Schleimer RP, et al: The effects of prostaglandin synthesis inhibition on the immune response. Immunopharmacology 3:205, 1981.
8. Leung KH, et al: Modulation of the development of cell mediated immunity: possible roles of the products of cyclooxgenase and lipoxygenase pathways of arachidonic acid metabolism. Int J Immunopharmacology 4:195, 1982.
9. Veit BC: Immunoregulatory activity of cultured-induced suppressor macrophages. Cell Immunol 72:14, 1982.
10. Schmitt M, et al: Biopharmaceutical evaluation of carprofen following single intravenous, oral, and rectal doses in dogs. Biopharm Drug Dispos 11(7):585–94, 1990.
11. Kore AM: Toxicology of nonsteriodal anti-inflammatory drugs. Veterinary Clinics of North America, Small Animal Practice 20, March 1990.
12. Binns SH: Pathogenesis and pathophysiology of ischemic injury in cases of acute renal failure. Compend for Cont Ed 16:1, January 1994.
13. Boothe DM: Prostaglandins: Physiology and clinical implications. Compend for Cont Ed 6:11, November 1984.
14. Rubin SI: Nonsteroidal anti-inflammatory drugs, prostaglandins, and the kidney. JAVMA 188:9, May 1986.
15. Ko CH, Lange DN, Mandsager RE, et al: Effects of butorphanol and carprofen on the minimal alveolar concentration of isoflurane in dogs. JAVMA 217:1025–1028, 2000.

For a copy of the Material Safety Data Sheet (MSDS) or to report adverse reactions call Pfizer Animal Health at 1-800-366-5288.

NADA #141-199, Approved by FDA

Distributed by:
Pfizer Animal Health
Div. of Pfizer Inc
NY, NY 10017

Made in Brazil

January 2010

054577 - Laetus 360