Butorphanol

Name: Butorphanol (butorphanol tartarate).

Trade Name(s): Torbugesic (injectable), Torbutrol (tablets).

Preparation: Sterile injectable liquid in 10ml or 50 ml mulitdose vials.  Each ml contains 10mg of butorphanol tartrate.

Description: Butorphanol tartrate is a synthetic, centrally acting, opioid agonist-antagonist analgesic classed as a narcotic under the Controlled Substances Act.

Availability: Butorphanol is a controlled drug and must be obtained through a licensed veterinarian.  Regulations regarding security and record keeping apply.

Indications: For the relief of mild to moderate, deep or visceral pain, and for chronic pain.  Some sedation accompanies the analgesia.

Dosage: Consult the laboratory animal veterinarian.

Routes of administration: Intramuscular, subcutaneous, or intavenous

Duration of action: About 4 hours

Mechanism of analgesic action: Butorphanol is a synthetic opioid agonist-antagonist analgesic acting at the m and k receptors.

Clinical pharmacology: Butorphanol tartrate is a member of the phenanthrene chemicals.  The chemical name is morphine-3, 14-diol, 17-(cyclobutylmethyl)-, (-),

(S-(R*,R*))-2,3-dihydroxybutanedioate (1:1).  In animals, butorphanol has been demonstrated to be 4-30 times more potent than morphine.  Butorphanol also has potent antitussive activity.

Physiological effects:

         Cardiovascular: Cardiopulmonary depressant effects are minimal.

         Respiratory: Cardiopulmonary depressant effects are minimal.

Drug Interactions: used with caution with other sedative or analgaesic drugs as these are likely to produce additive effects.

Notes:

References:

Pain Management in Animals.  2000  Flecknell P and Waterman-Pearson A (eds). WB Saunders, London  184pp

Laboratory Animal Anesthesia.  1996.  Flecknell P.  Academic Press, London.  274 pp.

Compendium of Veterinary Products, 6th Ed.  1999.  Canadian Animal Health Institute.  North American Compendiums, Hensall, Ontario