Opiod Drugs

Front 1

What are the opiod receptors that gives analgesia? .

Back 1

Mu, kappa and delta receptors.

Front 2

What are the general actions of opiods on the CNS ? (6)

Back 2

1) It produces analgesic actions by binding to opiod receptors in the brain and spinal cord. Pure mu agonist drugs are most useful.

2) When given alone it has tranquilising actions and when given at high doses t is a sedative. It increases with other drugs, age and diseases. CNS stimulation occurs with horses and cat, use with ace or alpha 2 - agonist. Dysphoria and aggresion can occur at higher doses.

3) Inhibits coughing.

4) Vomiting occurs with dogs given morphine. Effects reduced with ace.

5) Reduces body temp. Dogs will pant.

6) Constricts pupils in dog (Miosis).
Mydriasis in cats and other animals.

Front 3

What are the 2 effects of opiods on the heart?

Back 3

1)It slows the heart down and is dose related. Bradyarrthmias > first > second > thrid atriventricular block.
These arrthmias are mediated via the vagus and respond to anticholinergic administration.

2) Minimal depressive effects on the myocardium contractility. Decrease in blood pressure. Morphine and pethidine release histamine and causes the skin reddening and skin wheals are indicators of histamine release with these drugs.

Front 4

What are the effects of opiods on the respiratory system?

Back 4

All wil depress respiratory system and effect is related to dose given.
Respiratory rate and tidal volume is decreased.
Will cross placenta and depress resp centres of neonates.

Front 5

What are the effects of opiods on the GI and urinary tract?

Back 5

Increase GI motility and then slows it. Will defecate. multiple doses will produce constipation.
Will cause urinary rentention because of increased urethral tone.

Front 6

Morphine:
1- What class of drug is it?
2- What can you combine it with?
3- What is it contraindicated in?
4- What happens if you give it IV?
5- What does high doses produce?

Back 6

1) Mu opiod receptor agonist which weak actions on kappa and deltoid.

2) Can be given with tranquilisers for sedation like with ace. Give in low doses to cats.

3) COntraindicated in dogs with GDV, gastric torsion, animals with oesophageal torsion, foreign body, resp disease, gastric ulcers, pancreatitis and hepatitis.

4) Histamine released IV.

5)High doses produce panting.

Front 7

What are the 3 characteristic of methadone?
-clsss of drug
- what can it be mixed with?
- What is the advantage of methadone over morphine?

Back 7

1) Mu opiod agonist and is a NMDA antagonist in the spinal cord. SImilar to morphine.

2) Can be mixed with ace to produce sedation.

3) Does not produce vomiting.

Front 8

What are the 3 characteristic sof fentanyl?

Back 8

1) Synthetic mu opiod with high potency and great analgesic actions.

2) Short duration. Given when neded or on a patch

3) Produces bradycardia and actions on blood pressure and CO are minimal. Indicated for animals with heart disease.

Front 9

What are the 3 characteristic of pethidine?

Back 9

1) Synthetic opiod mu agonist with much less potency than that for morphine. Short duration of action.

2) Weak tranquilising actions. light sedation when combined with ace.

3) Release histamine when injected.

Front 10

What are the 3 characteristics of Oxymorphone?

Back 10

1) Synthetic mu agonist that is more potent than morphine.

2) Produces light sedation in the dog and cat. Increases with ace.
3) Not in australia

Front 11

What are the 3 characteristic sof buprenorphine?

Back 11

1) partial mu opoid agonist and is dereived from opium alkaloid. High affinity for mu receptor. If given with pure mu agonist the agonist effect is inhibited.

2) Long duration of analgesia. Weak tranquilising actions with ace. Req 30 min to work.

3) For dogs and cats for analgesia. Light tranquilisation in cats, drip under tongue for dog.

Front 12

What are the 4 characteristics of butorphanol?

Back 12

1) Synthetic opiod agonist/antagonist, moderate affinity with kappa receptor where it is an agonist and low affinity receptor with mu (antagonist).

2) tranquilising actions when given alone. Add ace for sedation. Weak analgesia but good visceral analgesia.

3) minimal cardiovascular depression.

4) strong cough depressive effects.

Front 13

What are the 2 characteristic sof pentazocine?

Back 13

1) Synthetic agonist/antagonist. Agonist in the kappa receptor and antagonist in the mu receptor

2) Weak tranquilising actions. May cause dysphoria in cats. Weak analgesic.

Front 14

What is the 2 ACTIONS of Naloxone?

Back 14

1) Pure competitive antagonist. NO agonist action. readily blocks mu receptors but less effective for delta and least for kappa. Higher doses req for butorphanol. may cause seizures at higher doses.

2) No Cardiopulmonary effects.

Front 15

What are neuroleptanalgesics?

Back 15

Combination of tranquiliser with an opiod. Increases sedation and reduces undesirable effects of opiods.