Term
| specifically which drugs are classified as preanesthetics |
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Definition
- Anticholinergics
- Tranquilizers and sedatives
- Phenothiazines
- Benzothiozines
- Alpha2-adrenoceptor agonists (alpha2- agonists)
- Opioids |
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Term
| be able to describe the reasons to give preanesthetic drugs. |
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Definition
To give:
- To calm or sedate an excited, frightened, or vicious animal
- to minimize adverse effects of concurrently administered drugs
- to reduce the required dose of concurrently administered agents
- to produce smoother anesthetic inductions and recoveries
- to decrease pain and discomfort before, during, and after sx
- to produce muscle relaxation |
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Term
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Definition
| one of the two types of acetylcholine receptors in the PNS, located on the target organs. Anticholinergics competitively block binding of the neurotransmitter acetylcholine at the muscarinic receptors |
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Term
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Definition
| one of the two types of acetylcholine receptors in the PNS, located on the postganglionic neurons at the junction with the preganglionic neurons |
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Term
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Definition
the tenth cranial nerve, provides parasympathetic innervation to numerous target organs incl the heart, lungs, GI tract, some secretory glands , and the iris of the eye. During sx, it may be stim by
-endotracheal intubation
- traction on visceral organs during abdo sx (viscerovagal reflex)
- manipulation of eye during ocular sx (oculovagal reflex)
- by some drugs incl the alpha2-agonists, opioids, and common gen anes. Increased binding of acetylcholine to the muscarinic receptors caused by vagal stim results in observable parasympathetic effects at the target organs.
Parasympathetic effects at target organs
- bradycardia
- bronchoconstriction
- excess tear and saliva production
- excess production of resp sys secretions
- increased GI motility
- miosis |
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Term
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Definition
| Neuroleptanalgesia is a state of profound sedation and analgesia induced by the simultaneous administration of an opioid and a tranquilizer. Commonly used for procedures that require significant CNS depression and analgesia but not general anesthesia. |
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Term
| the specific drugs that could be used to produce a Neuroloptoanalgesic combination |
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Definition
Opioids commonly used incl
- morphine
- buprenorphine
- butorphanol
- hydromorphone
Tranquilizers incl
- ace
- diazepam
- midazolam
- xylazine
- dexmedetomidine |
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Term
| Why are/were anticholinergics (such as atropine) given? |
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Definition
Anticholinergics (such as atropine) given for
- prevention of bradycardia
- increased heart rate
- reduction of resp, GI , salivary, and lacrimal secretions
- mydriasis
- bronchodilation |
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Term
| Adverse effects of anticholinergics |
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Definition
Adverse effects:
- cardiac arrhythmias
- thickening of resp and salivary secretion
- inhibition of peristalsis |
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Term
| properties of Atropine sulfate, its uses, indications, and contraindications |
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Definition
Available in 2 strengths that vary in concentration by a factor of 30 – always check concentration on bottle!
Atropine not preferred for preanes over glyco but atropine better choice for er tx for bradycardias assoc with cardiopulmonary arrest, due to its faster onset |
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Term
| `Know and be able to describe the properties of the Opioid drugs described in the text. |
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Definition
- used for analgesia, sedation, and, combined with other agents, anesthetic induction
- classified as agonists, partial agonists, agonist-antagonists, or antagonists, depending on predominant effects
- wide safety margin, can be used on healthy or debilitated pts
- opioid receptors found throughout the body but their analgesic and sedative effects are mainly the result of their action on receptors located in the brain and spinal cord.
- 3 types of opioid receptors
- mu
- kappa
- delta
- mode of action not completely understood
- agonists are the best drugs available for mod to severe pain, effect primarily by binding to and stimulating the mu and kappa receptors
- partial agonist only partially stimulate opioid receptors
- Agonist-antagonist only stim kappa not mu
- Pure antagonist are called reversal agents because displace agonists from the receptors and block effects as they bind but do not stimulate. Have no clinical effect on their own but are used to reverse the other types
- relatively short duration of action (1/2 to 3 hrs) with few exceptions like buprenorphine (6 – 8 hrs) and morphine (6 – 8 hrs in horses)
Major effects:
- CNS depression in dogs (if high doses given, esp to a sick animal, a sleeplike state called narcosis may occur)
- CNS excitement in cats and lg animals with some opioids (such as morphine), more pronounced with pure agonists – must be given at low doses to these spp and IV inj avoided
- Excellent somatic and visceral analgesia, particularly useful when incl in premeds
- Bradycardia
- Panting in dogs
- Miosis in dogs and mydriasis in cats and lg animals
- Increased responsiveness to noise
Major adverse effects:
- anxiety, disorientation, excitement, dysphoria, and increased motor activity
- pronounced bradycardia
- decreased resp rate and tidal vol
- salivation and vomiting in sm animals
- initial diarrhea and flatulence, then ileus
- drug interactions – some, particularly meperidine, may cause potentially fatal serotonin syndrome when given to animals receiving monoamine oxidase inhibitors such as selegiline or tricyclic antidepressants such as clomipramine.
Used to prevent and treat postoperative pain and often used in combo with a tranq to achieve a state of profound sedation and analgesia termed neuroleptanalgesia |
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Term
| Be able to list the specific Opioid drugs described in the text and their classification |
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Definition
Commonly used:
Agonists –
- morphine
- hydromorphone
- oxymorphone
- fentanyl
- meperidine
Partial Agonist
- buprenorphine
Agonist-atagonist
- butorphanol
- nalbuphine
Antagonist
- naloxone
Agonists used for wild animal capture
- etorphine
- carfentanil
With the exception of the antagonist and naloxone, opioids are controlled drugs. |
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Term
| Know and be able to describe the properties of the Alpha-2 adrenergic drugs described in the text. |
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Definition
Major effects
- Dose-dependent sedation that can be profound
- Analgesia
- Decreased cardiac output, HR, and BP
- Decreased RR and tidal vol
- Muscle relaxation
- Vomiting in dogs and cats
Major adverse effects:
- agitation or aggression when touched
- rxn to loud noises
- ataxia and falling in cattle
- severe bradycardia, hypotension, and decreased cardiac output
- severe resp depression |
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Term
| which specific reversal agents are used with Opioids. |
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Definition
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Term
| which specific reversal drugs are used with Alpha-2 adrenergic drugs? |
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Definition
| Yohimbine, tolazoline, atipamezole |
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Term
| What may happen with the admin of anticholinergics to reduce the incidence of alpha2-agonist induced bradycardia |
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Definition
| Admin of anticholinergics to reduce the incidence of alpha2-agonist induced bradycardia is not always effective and may in fact increase the workload of the heart, worsen bradycardia, or cause tachyarrhythmias. If bradycardia develops, the best tx is admin of an appropriate reversal agent |
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Term
| major effects/adverse effects anticholinergics such as atropine/glycopyrralate |
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Definition
Major effects:
- prevention of bradycardia
- increased heart rate
- reduction of redp, GI, salivary, and lacrimal secretions
- mydriasis
- bronchodilation
Adverse effects:
- cardiac arrhythmias
- thickening of resp and salivary secretion
- inhibition of peristalsis |
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