Thiazine Derivatives Flashcards
What is another name for thazine derivatives?
alpha-2 adrenoceptor agonists
What are four drugs in thiazine derivative group?
Xylazine (Rompun, Anased, Gemini) 20 mg/mL or 100 mg/mL
Detomidine (Dormosedan)
Medetomidine (Domitor)
Romifidine
What two xylazine dosage strengths are commonly available?
20 mg/mL or 100 mg/mL
What are the effects of administration of thiazine derivatives?
Produce calming Potent sedative
Good muscle relaxation
Good analgesia, of relatively short duration
Cardiopulmonary effects
What is the duration of the four thiazine derivatives?
Xylazine 20 – 40 min IV
Detomidine 90 – 120 min IV
Medetomidine 45 – 90 min IV
Romifidine 45 – 90 min IV
What routes of administration can be used for thiazine derivatives?
Can be administered epidurally – regional anesthesia
May be absorbed through mucous membranes, broken skin
Administered IM or IV
How does the cattle dosage of thiazine derivatives differ from horses?
cattle get 1/5 – 1/10 horse dose for same amount of body weight
What are the potentially negative effects of thiazine derivatives?
Decreased heart rate
May cause 1st or 2nd degree heart block
Cardiac output may decrease 30-50%
Initially, vasoconstriction, then may decrease blood pressure
Respiratory depression
Stridor and dyspnea may occur in horses and brachycephalic dogs
May increase blood glucose
Diuresis
Sweating in horses
May produce profound sleep in dogs, cats, foals, and small ruminants
What effect of thiazine derivatives may negatively effect ruminants?
Decreased salivation, gastric secretions and GI motility may cause bloat in ruminants
Crosses placenta – may cause oxytocin-like effect on cows premature delivery
What effects of thiazine derivatives may negatively effect dogs and cats?
Vomiting in dogs and cats; may predispose large breeds dogs to bloat
May produce profound sleep in dogs, cats, foals, and small ruminants
Stridor and dyspnea may occur in horses and brachycephalic dogs
What effect may thiazine produce on an excited animal?
If excited when administered, may have opposite of desired effect, or no effect
What are two thiazine derivative antagonists?
Yohimbine for Xylazine
Atipamazole for Medetomidine
How are thiazine derivatives absorbed and excreted?
Rapidly absorbed – IM administration
Relatively rapidly metabolized by liver, excreted in urine
Define acute tolerance.
animal is not effected by a certain drug
