TILETAMINE HCL / ZOLAZEPAM HCL, (Telazol®)
Chemistry - Tiletamine is an injectable anesthetic agent chemically related to ketamine. Zolazepamis a diazepinone minor tranquilizer. The pH of the injectable product after reconstitution is 2.2 - 2.8.
Its effect on respiratory activity is controversial, and until these effects have been clarified respiratory function should be closely monitored. The pharmacology of this drug combination is similarto that of ketamine and diazepam. For more information refer to the monographs for those agents.
In cats, the onset of action is reported to be within 1-7 minutes after IM injection. Duration ofanesthesia is dependent on dosage, but is usually about 0.33-1 hour at peak effect. This is reportedto be approximately 3 times the duration of ketamine anesthesia. The duration of effect of thezolazepam component is longer than that of the tiletamine, so there is a greater degree oftranquilization than anesthesia during the recovery period. The recovery times vary in length fromapproximately 1-5.5 hours.
In dogs, the onset of action following IM injection averages 7.5 minutes. The mean duration ofsurgical anesthesia is about 27 minutes, with recovery times averaging approximately 4 hours. Theduration of the tiletamine effect is longer than that of zolazepam, so there is a shorter duration oftranquilization than there is anesthesia. Less than 4% of the drugs are reported to be excretedunchanged in the urine in the dog.Contraindications/Precautions - Telazol® is contraindicated in animals with pancreatic disease, severe cardiac or pulmonary disease. Animals with renal disease may have prolonged durations ofanesthetic action or recovery times.
Telazol® crosses the placenta and may cause respiratory depression in newborns; the manufacturer lists its use in cesarian section as being contraindicated. The teratogenic potential of the drugis unknown, and it is not recommended to be used during any stage of pregnancy.
Because Telazol® may cause hypothermia, susceptible animals (small body surface area, lowambient temperatures) should be monitored carefully and supplemental heat applied if needed. Likeketamine, Telazol® does not abolish pinnal, palpebral, pedal, laryngeal, and pharyngeal reflexes andits use (alone) may not be adequate if surgery is to be performed on these areas.
This drug has been reported to be contraindicated in rabbits.
Cat's eyes remain open after receiving Telazol® , and they should be protected from injury and anophthalmic lubricant (e.g., Lacrilube®) should be applied to prevent excessive drying of the cornea.
Cats reportedly do not tolerate endotracheal tubes well with this agent.
Dosages may need to be reduced in geriatric, debilitated, or animals with renal dysfunction.
In dogs, tachycardia may be a common effect and may last for 30 minutes. Insufficient anesthesiaafter recommended doses has been reported in dogs.
Other adverse effects listed by the manufacturer include: emesis during emergence, excessivesalivation and bronchial/tracheal secretions (if atropine not administered beforehand), transientapnea, vocalization, erratic and/or prolonged recovery, involuntary muscular twitching, hypertonia, cyanosis, cardiac arrest, pulmonary edema, muscle rigidity, and either hypertension or hypotension.
Overdosage - The manufacturer claims a 2X margin of safety in dogs, and a 4.5 times margin ofsafety in cats. A preliminary study in dogs (Hatch et al. 1988) suggests that doxapram at 5.5 mg/kgwill enhance respirations and arousal after Telazol®. In massive overdoses, it is suggested thatmechanically assisted ventilation be performed if necessary and other symptoms be treatedsymptomatically and supportively.
Phenothiazines can cause increased respiratory and cardiac depression when used with thisproduct.
The dosage of barbiturate or volatile anesthetics may need to be reduced when used concomitantly with Telazol®. For general guidelines with regard to drug interactions with this product, please refer to the ketamine and diazepam monographs.
Storage, Stability, Compatibility
After reconstitution, solutions may be stored for 4 days atroom temperature and 14 days if refrigerated. Do not use solutions that contain a precipitate or arediscolored.Pharmacology - TILETAMINE HCL/ZOLAZEPAM HCL, (Telazol®)
In cats, tiletamine decreases cardiac rate and blood pressure after IM injections.Its effect on respiratory activity is controversial, and until these effects have been clarified respiratory function should be closely monitored. The pharmacology of this drug combination is similarto that of ketamine and diazepam. For more information refer to the monographs for those agents.
Uses, Indications
Telazol® is indicated for restraint or anesthesia combined with muscle relaxation in cats, and for restraint and minor procedures of short duration (ยป30 minutes) which require mild to moderate analgesia in dogs. Although not officially approved, it has been used also inhorses and many exotic and wild species.Pharmacokinetics - TILETAMINE HCL/ZOLAZEPAM HCL, (Telazol®)
Little pharmacokinetic information is available for these agents. The onset ofaction may be variable and be very rapid; animals should be observed carefully after injection.In cats, the onset of action is reported to be within 1-7 minutes after IM injection. Duration ofanesthesia is dependent on dosage, but is usually about 0.33-1 hour at peak effect. This is reportedto be approximately 3 times the duration of ketamine anesthesia. The duration of effect of thezolazepam component is longer than that of the tiletamine, so there is a greater degree oftranquilization than anesthesia during the recovery period. The recovery times vary in length fromapproximately 1-5.5 hours.
In dogs, the onset of action following IM injection averages 7.5 minutes. The mean duration ofsurgical anesthesia is about 27 minutes, with recovery times averaging approximately 4 hours. Theduration of the tiletamine effect is longer than that of zolazepam, so there is a shorter duration oftranquilization than there is anesthesia. Less than 4% of the drugs are reported to be excretedunchanged in the urine in the dog.Contraindications/Precautions - Telazol® is contraindicated in animals with pancreatic disease, severe cardiac or pulmonary disease. Animals with renal disease may have prolonged durations ofanesthetic action or recovery times.
Telazol® crosses the placenta and may cause respiratory depression in newborns; the manufacturer lists its use in cesarian section as being contraindicated. The teratogenic potential of the drugis unknown, and it is not recommended to be used during any stage of pregnancy.
Because Telazol® may cause hypothermia, susceptible animals (small body surface area, lowambient temperatures) should be monitored carefully and supplemental heat applied if needed. Likeketamine, Telazol® does not abolish pinnal, palpebral, pedal, laryngeal, and pharyngeal reflexes andits use (alone) may not be adequate if surgery is to be performed on these areas.
This drug has been reported to be contraindicated in rabbits.
Cat's eyes remain open after receiving Telazol® , and they should be protected from injury and anophthalmic lubricant (e.g., Lacrilube®) should be applied to prevent excessive drying of the cornea.
Cats reportedly do not tolerate endotracheal tubes well with this agent.
Dosages may need to be reduced in geriatric, debilitated, or animals with renal dysfunction.
Adverse Effects, Warnings
Respiratory depression is a definite possibility, especially withhigher dosages of this product. Apnea may occur; observe animal carefully. Pain after IM injection(especially in cats) has been noted which may be a result of the low pH of the solution. Athetoidmovements (constant succession of slow, writhing, involuntary movements of flexion, extension, pronation, etc) may occur; do not give additional Telazol® in the attempt to diminish these actions.In dogs, tachycardia may be a common effect and may last for 30 minutes. Insufficient anesthesiaafter recommended doses has been reported in dogs.
Other adverse effects listed by the manufacturer include: emesis during emergence, excessivesalivation and bronchial/tracheal secretions (if atropine not administered beforehand), transientapnea, vocalization, erratic and/or prolonged recovery, involuntary muscular twitching, hypertonia, cyanosis, cardiac arrest, pulmonary edema, muscle rigidity, and either hypertension or hypotension.
Overdosage - The manufacturer claims a 2X margin of safety in dogs, and a 4.5 times margin ofsafety in cats. A preliminary study in dogs (Hatch et al. 1988) suggests that doxapram at 5.5 mg/kgwill enhance respirations and arousal after Telazol®. In massive overdoses, it is suggested thatmechanically assisted ventilation be performed if necessary and other symptoms be treatedsymptomatically and supportively.
Drug Interactions
Little specific information is available presently on drug interactions with thisproduct. In dogs, chloramphenicol apparently has no effect on recovery times with Telazol®, butin cats, anesthesia is prolonged on average of 30 minutes by chloramphenicol. Cats wearing fleacollars have not been demonstrated to have prolonged anesthesia times.Phenothiazines can cause increased respiratory and cardiac depression when used with thisproduct.
The dosage of barbiturate or volatile anesthetics may need to be reduced when used concomitantly with Telazol®. For general guidelines with regard to drug interactions with this product, please refer to the ketamine and diazepam monographs.