X-Ject E: Product Information

X-JECT E- xylazine injection, solution
Henry Schein

DESCRIPTION: The chemical name for xylazine is 2-(2,6-dimethylphenylamino)-4H-5,6-dihydro-1,3-thiazine.

The formula for hydrochloride salt is C12 H16 N2 S HCl. X-Ject E Injection is a clear, colorless solution containing 100mg/mL xylazine base. It is for intravenous or intramuscular administration to horses.

Each mL CONTAINS: Xylazine HCl equivalent to 100 mg xylazine base; 0.9 mg methylparaben and 0.1 mg propylparaben as preservatives; 6.12 mg sodium citrate dehydrate; water for injection, q.s.

Hydrochloric acid and/or sodium citrate dehydrate may also be used, as necessary, for pH adjustment.

INDICATIONS: X-Ject E Injection should be used in horses when it is desirable to produce a state of sedation. It has been successfully used when conducting various diagnostic, orthopedic and dental procedures and for minor surgical procedures of short duration. It may also be used as a preanesthetic to local or general anesthesia.

DOSAGE AND ADMINISTRATION: For intravenous or intramuscular administration in horses.

The recommended dosage for intravenous administration is 0.5 mL/100 lbs body weight (0.5mg/lb). The recommended dosage for intramuscular administration is 1.0 mL/100 lbs body weight (1.0 mg/lb).

Use product within 31 days of first puncture. Do not puncture the stopper more than 30 times.

Following administration of X-Ject E Injection, the animals should be allowed to rest quietly until the full effect has been reached. These dosages produce a state of sedation which is usually maintained for 1 to 2 hours.

Preanesthetic to local anesthesia-At the recommended dosage rates, X-Ject E Injection may be used in conjunction with local anesthetics, such as procaine and lidocaine.

Preanesthetic to general anesthesia-At the recommended dosage rates, X-Ject E Injection produces an additive effect to central nervous system depressants, such as sodium pentobarbital, sodium thiopental and sodium thiamylal. Accordingly, the dosage of such compounds should be reduced and administered to the desired effect. Generally, 1/3 to 1/2 of the calculated dosage of the barbiturates will be needed to produce a surgical plane of anesthesia. Postanesthetic or emergence excitement has not been observed in animals preanesthetized with X-Ject E Injection.

X-Ject E Injection has been successfully used as a preanesthetic agent for sodium pentobarbital, sodium thiopental and sodium thiamylal, nitrous oxide, ether, halothane glyceryl guaiacolate and methoxyflurane anesthesia.

CONTRAINDICATIONS: Xylazine should not be used in conjunction with neuroleptics or tranquilizers.1 4 5

WARNING: Intracarotid Arterial Injection Should be Avoided. As with many drugs including tranquilizers, immediate and violent seizures followed by collapse may result from inadvertent administration into the carotid artery. Although the reaction with xylazine is usually transient and the recovery rapid and complete, special care should be taken to assure that the needle is in the jugular vein rather than the carotid artery.

Do not use in horses intended for human consumption.

PRECAUTIONS: Debilitated animals with depressed respiration, cardiac disease, renal and liver impairment, shock or any other stress conditions should be carefully monitored whenever xylazine is administered.1

Because xylazine produces an additive effect to central nervous system depressants, caution should be taken when administering barbiturate compounds in conjunction with xylazine. These drugs should be given at a reduced dosage to the desired effect, and when injected intravenously, should be given slowly.

Arrhythmias, resulting in partial AV blocks, and bradycardia are transient changes which may occur, but that can be counteracted to a large degree by the administration of atropine prior to or following xylazine injection.1 3 4 5

Analgesic effect is variable, and depth should be carefully determined prior to surgical/clinical procedures. Variability of analgesia occurs most frequently at the distal extremities of the horse. In spite of sedation, the practitioner should proceed with caution, since defense reactions may not be diminished. Sedation for transport is most successful if the actual transportation is initiated after full effect of the drug has been obtained and the animal’s stability maintained in the standing position. It should be noted that animals under the influence of xylazine are particularly sensitive to noise and care should be taken accordingly, to avoid risk of injury.

ADVERSE REACTIONS: The deep sedation produced by xylazine is characterized by lowering of the head, drooping of the eyelids and lower lip and a marked reluctance to move.1 6 Most horses given xylazine sweat around the ears and poll region, and may seem particularly sensitive to sharp auditory stimuli during the recovery period.1 4 6 7 The respiratory and pulse rate are reduced as in natural sleep.1 3 4 5 Transient changes in the conductivity of the cardiac muscle (resulting in partial AV blocks), bradycardia, decreased cardiac output and a rise in arterial blood pressure may occur following intravenous administration.1 3 4 5 6 7

CLINICAL PHARMACOLOGY: Xylazine is pharmacologically classified as a non-narcotic sedative.1 2 3 4 The drug causes sedation by acting upon a-adrenergic receptors in the brain to prevent the release of norepinephrine.5 Xylazine also produces muscle relaxation by inhibiting the intraneural transmission of impulses to the central nervous system.1 4

Deep sedation develops in the horse within 10 to 15 minutes after intramuscular injection, and within 3 to 5 minutes following intravenous administration.1 2 4 6 7 Deep sedation lasts 15 to 20 minutes, while a sleep-like state, the depth of which is dose-dependent, is usually maintained for 1 to 2 hours following intramuscular administration of the drug at the recommended dosage.1 2 4 6 7 Recovery is complete within 30-40 minutes following intravenous injection.1 2 6 7

In animals under the influence of xylazine, the respiratory and pulse rates are reduced as in natural sleep.1 3 4 5 The intramuscular injection of xylazine produces only negligible effects on the cardiovascular and respiratory systems. However, intravenous administration in the horse may cause transient changes in the conductivity of the cardiac muscle, evidence by partial atrioventricular (AV) blocks, bradycardia, decreased cardiac output and a rise in arterial blood pressure.1 3 4 5 6 7 These actions are transient and can be counteracted to a large degree by the administration of atropine prior to or following xylazine injection.1 3 4 5 Xylazine has no effect on blood clotting time or other hematologic parameters.4

Although not devoid of undesirable attributes, xylazine seems to posses certain properties which make it a better sedative for horses than any other compound currently in use.6 7 It is more dependable, results in less respiratory depression and greater cardiovascular stability and has resulted in a higher percentage of quieter recoveries from surgical anesthesia in the horse than when promazine hydrochloride or acepromazine maleate is used for preanesthetic medication.1 7

ANIMAL SAFETY: Xylazine is tolerated in horses at 10 times the recommended dosage, however, doses of this magnitude produce muscle tremors and long periods of sedation.4

STORAGE: Store at up to 25°C (77°F).


HOW SUPPLIED: X-Ject E Injection, 100 mg/mL xylazine base, is available in 50 mL multi-dose vials.

NADA 140-442, Approved by FDA


1. Booth, N.H. and L.E. McDonald. 1982. Veterinary Pharmacology and Therapeutics , 5th ed. Iowa State University Press, Ames, IA 311-316.

2. Rossoff, I.S. 1974. Handbook of Veterinary Drugs. Springer Publishing Co., New York, NY. 662.

3. Howard, J.L. 1981. Current Veterinary Therapy. Food Animal Practice. W.B. Saunders Co., Philadelphia, PA. 63.

4. Grey, R.M. 1974. Veterinarians’ Product and Therapeutic Reference. 3rd ed. Edward Nottage, Publisher. 64-67.

5. Upson, D.W. 1985. Handbook of Clinical Veterinary Pharmacology. 2nd ed. Veterinary Medicine Publishing Co., Lenexa, KS. 216-218.

6. Hall, L.W. 1971. Wright’s Veterinary Anesthesia and Analgesia. 7th ed. Williams & Wilkins Co., Baltimore, MD. 161-163.

7. Soma, L.R. 1971. Textbook of Veterinary Anesthesia. Williams & Wilkins Co., Baltimore, MD. 324.

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xylazine injection injection, solution
Product Information
Product Type PRESCRIPTION ANIMAL DRUG Item Code (Source) NDC:11695-7085
Route of Administration INTRAVENOUS, INTRAMUSCULAR DEA Schedule
Active Ingredient/Active Moiety
Ingredient Name Basis of Strength Strength
Xylazine (XYLAZINE) Xylazine 100 mg in 1 mL
Inactive Ingredients
Ingredient Name Strength
SODIUM CITRATE 6.12 mg in 1 mL
# Item Code Package Description Multilevel Packaging
1 NDC:11695-7085-1 50 mL in 1 VIAL, GLASS None
Marketing Information
Marketing Category Application Number or Monograph Citation Marketing Start Date Marketing End Date
NADA NADA140442 10/05/2015 09/28/2018
Labeler — Henry Schein (603750329)

Revised: 01/2016 Henry Schein

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