Name: Xylazine

Trade Name(s): Rompun, Anased, Xylazine HCl Injection

Preparation: Sterile injectable liquid packaged in 20 ml vials with a concentration of 20 mg/ml, or 50 ml vials with a concentration of 100 mg/ml.

Description: Xylazine is an alpha-2-adrenergic agonist sedative with analgesic properties.

Availability: Xylazine is a prescription drug.

Indications: Used alone for short minor manipulations or minor surgical procedures.  See below for use in combination with other drugs for anesthesia.

Dosage: Consult the laboratory animal veterinarian.

Routes of administration: Intramuscular, subcutaneous, or intravenous

Duration of action: Sedation lasts a few hours; the analgesia is of shorter duration.  ROMPUN is a potent sedative and analgesic as well as a muscle relaxant. Its sedative and analgesic activity is related to central nervous system depression. Its muscle-relaxant effect is based on inhibition of the intraneural transmission of impulses In the central nervous system.  Sedation develops within 10-15 minutes after intramuscular injection and within 3-5 minutes following intravenous administration.

Mechanism of analgesic action: Xylazine is an alpha-2-adrenergic agonist sedative with analgesic properties.  Its sedative properties relate to central nervous system depression.  The muscle ­relaxant properties relate to inhibition of the Intraneural transmission of Impulses In the central nervous system.

Clinical pharmacology: The sedation and muscle relaxation produce a sleep-like state, with decreased respiratory and heart rates.  There is significant depression of respiration and heart rate.  The decrease in heart rate is related to a transient change in conductivity of cardiac muscle due to a partial atrioventricular block.

Physiological effects:

         Cardiovascular: Significant depession of heart rate

         Respiratory: Significant respiratory depression

Drug Interactions: Should not be used in combination with other tranquilisers.  There are additive effects when used in combination with anesthetics or analgesics and then required doses would be lower.

Notes: In dogs and cats vomiting may occur soon after administration of xylazine.

References:

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

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.