anaesthesia 4 - sedatives and tranquilizers

Question 0

what is a anxiolytic?

Answer 0

reduces anxiety without causing sedation

Question 1

what is a tranquiliser?

Answer 1

agent that effects mood

Question 2

what is a sedative?

Answer 2

agent that cause drowsiness

Question 3

what is a hypnotic?

Answer 3

depresses the CNS and induces sleep

Question 4

what is a neuroleptic?

Answer 4

reduces agression and agitation

Question 5

what are the 4 main groups of drugs used?

Answer 5

1. phenothiazines
2. butyrophenones
3. benzodiazepines
4. alpha 2 agonists

Question 6

what are phenothaizines used for? what are the effects on the CNS? antimetic? not an analgesic!!!

Answer 6

antisychotics /neuroleptics and anxiolytic
- dopamine antagonism. act as tranquiliser, sedative, anxiolytic (increasing dose does not increase sedation but only prolongs action. ) antiemetic properties (reduce sickness)
NO ANALGESIC!!!

Question 7

what are the side affects of phenothazines? 2 . effects on CVS? acts as a? GIT? other? how ddo they promote hypothermia?

Answer 7

movement disorders. (antagonist of dopamine - pituitary gland - increases prolactin release. )
CVS - blocks aplha1 receptors. cause vasodilation and hypotension. - antiarrythmic action - treat mitral valve disease. hypothermia.
GIT - antispasmodic
other - antihistamine, antimuscarinic, serotonin blockade.

Question 8

give the main example of a phenothazine? dose for small/large? why not to be used in stallion? main use?

Answer 8

ACP. acepromazine!!!, yellow solid crystal prepared in liquid gel/tablet form.
used as a pre-med (reduces dose of other anaesthetic.) anxiolytic, tranquiliser, sedative. used to treat travel sickness!.
small animal - 2mg/ml i/v or i/m.
large animals - 10mg/ml i/v or i/m to horses. NOT TO BREEDING STALLION AS causes protrusion of flaccid penis from prepuce/priapism. ( so do all others just it is recognised in this one!!.
also 10/25mg/ml tablets for dog/cat
ACP gel in horse 35mg/ml. (sedalin)

Question 9

what are the pharmaco kinetics of ACP?

Answer 9

oral F - 20-55%
DURATION OF 4-6 HOURS. 
ONSET QUICKER IN I/V (5 MINS)
liver met
urine excrete
combine with opoids of CV a problem.

Question 10

clincall properties of ACP? phenothiazine. used to treat what in horses? high dose = ? boxers prone to?why is iM preferred?

Answer 10

low doses - behavioral
high - sedation
used to calm horses at events
i/m preferred. anticonvulsant
boxers are prone to syncope so use low doses. 
used to treat laminitis!!!!

Question 11

other phenothiazines? eg’s of 2?

Answer 11

promazine - better sedation and fewer side effects

promethazine - irritant, given deeper IV. potent antihistamine.

Question 12

what do butyrophenones do?

Answer 12

they modify behavior. dopamine antagonism again in cns. SEDATIVE, potent antimetic, unpleasant sude effects.
CVS - vasodilate, hypotension. eg. azaperone 9pigs) .

Question 13

azaperone? eg of a? pharmacokinetics? high dose means?

Answer 13

butyrophenone. (1st one was a phenothiazine.) is s sedative in pigs (strensil) treats aggression and good for transport stress. + premed. give deep I/m (behind ear in pig)
leave for 20 mins.
2-3 hour duration
results in low bp, dose-related sedation.

Question 14

alpha 2 agonists?

Answer 14

covered in another lecture. also used for sedation, tranquilisation.

Question 15

3rd type are benzodiazepines: (1st - phenothiazines, 2nd - butyrophenones) . what can they be used instead of an why? how do they act?

Answer 15

used instead of ACP is cv problems. act via gaba mediated inhibiton. (inhibitory neourtransmitter in mammals. )
GABA!!

Question 16

how do benzodiazepines work via GABA? effects on CNS? effects on CVS/resp?

Answer 16

they bind to a gaba receptor and this cause cl channels to open. hyperpolarisation occurs and so reduced chance of a ap.

CNS - anxiolytic, muscle relax, anticonvulsant, sedate human
cvs - minimal depression on this or respiration!

NOT a great sedative for animals as horses - excited and cats - loopy!. only as last resort if cv a rpoblem with ACP.

Question 17

benzodiazepines have a synergistic effect with what? metabolised where?

Answer 17

central depressants. eg. barbituates, antihistamines. metabolised in the liver

Question 18

main exapmle of a benzodiazepine?

Answer 18

DIAZEPAM!!. valium.

Question 19

what are the main problems with diazepam? benzodiazepines. pharmacokinetics? pahrmacological?

Answer 19

may cause thrombophlebitis, pain on injection, cardiac arrythmias. it is rarely used as it is very expensive.
i/v or oral, rapid onset, liver metabolism, excrete in urine.

cns - variable sedation, muscle relaxant, aanticonvulsant. causes panic in horses.
cvs/resp =use in sick animals as has little cvs effects. (instead os ACP.)

Question 20

diazepam? type of benzodiazepine. (phenothaizines & bturopheneones) what is it used for? what do you comnibe it with in horse/smalls?

Answer 20

used i/v to control status epilepticus. stimulates appetite.
with ketamine in horses to induce anaethesia.
use as pre-med in compromised animals.

Question 21

midazolam? also called? used for? what type of drug? pharmacokinetics? ph means?

Answer 21

hypnovel. muscle relaxant. water soluble. iv/im/oral. rapid metabolism, short duration. ph = 3.5 so non-ionised in blood and cross membranes easily.

Question 22

give other examples of benzodiazepines? (phenothiazine, butyrophenone) combine mostly with what in horses?

Answer 22

climazolam, - in comb with ketamine in horses to maintain anaesthesia.
tolezepam - combined with ketamine

Question 23

what are benzodiazepine antagonists? what are they used for mainly?

Answer 23

fluzazenil - reverse sedation

sarmazenil - antagonise midazolam in horses

Question 24

what are inverse agonists? how do they act? what woildnt you use them in?

Answer 24

act at GABA. close chloride channels and so promote convulsions. not in horses as cause excitement.