Butadione

Category:  Non – Steroidal anti Inflammatory Drugs.

Pharmaceutical Form: Sterile Injectable Solution.

Composition: Phenylbutazone 200 mg/ml.   

Mechanism of Actions:
Eicosanoids, such as prostaglandins and leukotrienes, are 20-carbon – chain derivatives of cell membranes. Eicosanoids are potent mediators of inflammation and are particularly important in the later stages. Prostaglandins also modify both T- and B-cell function in part by in hibition of interleukin -2 secretion.  NSAID block the first step of prostaglandin synthesis by binding to and inhibition cyclooxygenase. Phenylbutazone is a Nonsteriodal anti-inflammatory drug (NSAID) Phenylbutazone and other NSAID have no direct effect on pain perception, - rather, they reduce hypersensitivity to pain by reducing the inflammatory response inflamed tissue.

PHARMACOKINETICS:
Phenylbutazone is readily absorbed following intravenous administration. Phenylbutazone is estimated to be 99% bound to plasma albumen.  Phenylbutazone is metabolized by the liver, with less than 2% of the drug being excreted as parent compound in the urine in some species.
Its major metabolites are oxyphenylbutazone, which is less active than phenylbutazone, and inactive δ hydroxy phenylbutazone.

INDICATIONS:
Phenylbutazone is a synthetic non steroidal anti- inflammatory drug
(NASID) used as an antipyretic, anti – inflammatory, and analgesic. It is indicated for use in the treatment of muscular and articular inflammations including arthritis of the hock, stifle and hip, generalized arthritis, Laminitis in horses, Cattle and dogs.

DOSAGE AND ADMINISTR ATIONS:
Administer by slow intravenous injection only observating the usual sterile procedure.
Ruminant: 9 mg per kg bodyweight, loading dose
2-5 mg per kg bodyweight, maintenance dose given every other day.
Horse: 2.2 – 4.4 mg per kg bodyweight, once daily for UP to 3 days.Dogs: 20 mg per kg bodyweight, once daily for up to 3 days.

ADVERSE AND COMMON SIDE EFFECTS:
Toxicity can occur in the horse if administered at a dose greater than the suggested recommendation, especially if a high dose is maintained for more than a few days. Signs of toxicity include anorexia, depression, oral and gastrointestinal ulcers, protein losing enteropathy, and death from shock. Neutropenia and sevele depletion of bone marrow neutrophils also occur. Renal papillary necrosis is also a consequence of toxicity, being more likely to occur in states of reduced renal blood flow such as dehydration.

Contra- Indication:
Phenylbutazone is contraindicated in animals with cardiac, renal, or hepatic insufficiency.

DRUG INTERACTIONS:
Phenylbutazone is highly bound to plasma proteins and can displace other drugs that bind to plasma proteins, such as other anti – inflammatory drugs, sulfonamides, or anticoagulants such as warfarin, leading to increased pharmacological effect or toxicity of the displaced drug.

Withdrawal time: milk: 7days after last treatment.
Meat: 28 days after last treatment.

Pharmaceutical precautions: store at room temperature, not exceeding 30°C, protected from light. Do not freeze.

Package quantities: 100 ml amber glass multidose vials.