parasympathetic and sympathetic nervous system

Question 1

M1 , M2, M3: where do they work?

- side effects

Answer 1

• M 1 ,M 3 stomach and glands, bronchial smooth
  muscle, eye ciliary muscle excitation –, vascular
  endothelium (NO) inhibition
• M 2 heart inhibition

- Side effects: 
bradycardia
bronchoconstrictio
miosis
salivation
vomiting, diaorrhea
urination

Question 2

Muscarinic ACh receptors:

- response to ACh binding =

Answer 2

G protein cascade is activated

Question 3

Indirect parasympathomimetics

- how they work

Answer 3

ACh esterase enzyme inhibition —> ACh

degradation is reduced

Question 4

Carbachol

Answer 4

non specific to M ACh receptors: several side effects
excellent activity, nowadays: exclusively locally
1. applied in the uterus in the case of metritis (intrauterine)

Question 5

1. Bethanechol

2. Methacholine

Answer 5

used in human medicine mostly

1. M- ACh specific
   induction of intestinal peristalsis after operations
   urinary bladder atony ! (veterinary field)

M ACh specific
cardiovascular system —> atrial fibrillation
pronounced peripherial vasodilatation —> ergot toxicosis

Question 6

Pilocarpine

• use
• side effects

Answer 6

natural alkaloid ( Pilocarpus jaborandi)
earlier: important role in ophtalmology
1. GLAUCOMA therapy (miosis can be seen after approx. 15 mins)
2. KCS (Keratoconjunctivitis sicca): effect is ambiguous
side effect: mild after local administration

Question 7

Direct parasympathomimetics

Answer 7

Acetylcholine (ACh)
Carbachol
Bethanechol
Methacholine
Pilocarpine

Question 8

Receptors for indirect parasympathomimetics:

Answer 8

 primarily on nicotinic ACh receptors
 furthermore on muscarinic ACh receptors
 on ACh receptors in the CNS

Question 9

Physostigmine

• characteristics
• use

Answer 9

• contains tertiary nitrogen –> lipophilic –> kinetics!
• very small therapeutic index systemically (atropine poisoning)
• eye drop : glaucoma treatment

Question 10

Neostigmine

• Characteristics
• use

Answer 10

•quaternary nitrogen —> less lipophilic –> kinetics!
•eye drop : treatment of glaucoma
•given systemically it is safer
- Given IV or IM

• myasthenia gravis treatment
  suspending the action of non depolarizing muscle relaxants
• increasing intestinal motility
• inducing emesis

Question 11

Pyridostigmine

• Characteristics
• admin
• use

Answer 11

• quaternary nitrogen –> less lipophilic –> kinetics!
  •given systemically it is safer
  •orally this has the best bioavailability (F=3 8% only)

Use:
myasthenia gravis treatment
increasing intestinal motility

Question 12

Edrophonium

• Characteristics
• effect, use

Answer 12

•competitive inhibition in the neuromuscular junction —> action is suspended by diffusion
•short effect: 5-15 minutes
- myasthenia gravis diagnosis = Tensilon test

Question 13

Organophosphates

• Characteristics
• use
• antidote

Answer 13

• irreversible
• inhibitors of AChE
• ectoparasiticides (e.g. diazinon)
• in humans treatment of glaucoma (e.g. echothiophate)
  antidote: atropine, pralidoxime

Question 14

Indirect parasympathomimetics

Answer 14

Organophosphates
Edrophonium
Pyridostigmine
Neostigmine
Physostigmine

Question 15

Atropine

Dose (mg/kg) Symptoms

Answer 15

Dose (mg/kg) Symptoms
0,5 :Mouth dryness, decreased perspiration
1: tachycardia, mydriasis
2: +accomodation, disturbances
5: +constipation
10: +ataxia, excitation, hallucination, delirium, coma

Question 16

Drugs used in:

1. diagnostic examination of the eye
2. in uveitis the prevention of synechiae

Answer 16

1. tropicamide,homatropine (short acting)

2. atropine (long acting)

Question 17

atropine was used earlier for

premedication which drug is most used now?

Answer 17

glycopyrrolate

Question 18

Drug used in treatment of horse RAO, COPD and human

(feline) asthma :

Answer 18

ipratropium

Question 19

decreases secretion and motility (used

in ruminants)

Answer 19

benzethimide

Question 20

decreases smooth muscle function –> antispasmodic

effect in the intestine –> very effective in horse colic

Answer 20

esp. butyl scopolamine

Question 21

Which animal is relatively resistant to atropine! (liver atropinase)

Answer 21

Rabbit

Question 22

Atropine toxicosis symptoms:

Answer 22

Symptoms: dry mouth, tachycardia, mydriasis, constipation, convulsions, coma, death

Question 23

α1 receptor effects:

Answer 23

smooth muscle contraction
*increased sphincter constriction
vasoconstriction
mydriasis

Question 24

α2 receptor effects:

Answer 24

inhibition of neurotransmitter release (NA!)
GI relaxation
inhibition of insulin release

Question 25

β receptors effects:

Answer 25

``` - β1 receptor cardiac effects (positive inotropic, chronotropic) ``` - β2 receptor vasodilatation bronchodilatation uterus relaxation - (β 3 receptor lipolysis in fat tissue)

Question 26

Nonspecific sympathomimetics

Answer 26

Adrenalin Noradrenalin Dopamine

Question 27

Adrenaline - receptors - effects - indications

Answer 27

- noncspecific: mainly β 1 and β 2 receptors * α-receptors in higher dosage cardiac effect arrhytmogenic! blood pressure increases indications: - cardiac stop - severe bronchoconstriction - anaphylaxia - local vasoconstriction (haemorrhages) - increase in duration of local anaesthetics

Question 28

Noradrenaline - receptors - effects - indications

Answer 28

- nonspecific (mainly β 1 and α 1 receptors) cardiac effect blood pressure is significantly increased! indications (rare): -hypotension

Question 29

Dopamine | - receptors

Answer 29

- low dose D 1 receptors (kidney!) - medium dose β 1 receptors (heart!) - high dose α 1 receptors (pressor)

Question 30

Specific sympathomimetics

Answer 30

Dobutamine Isoproterenol ``` Beta agonists: (mainly B2, higher doses B1) clenbuterole salbutamole terbutaline salmeterole isoxsuprine ```

Question 31

Dobutamine - receptors - effects - indication

Answer 31

- mainly β 1 receptors cardiac effect indications: -cardiogenic shock (IV. infusion)

Question 32

Isoproterenol

Answer 32

only β receptors ( β 1 and β 2) | - heart+bronchi+muscle vessels

Question 33

Which Beta 2 agonist is leaat lightly to cause cardiac effect?

Answer 33

clenbuterole 4:1 salbutamole 650:1 salmeterole 50000:1

Question 34

β2 agonists indications:

Answer 34

``` horse RAO feline asthma bronchitis, bronchopneumonia tracheal hypoplasia tracheal collapse ```

Question 35

Phenylephrine - receptors - uses

Answer 35

``` α adrenoceptor agonists mainly α 1 receptors --> vasoconstriction - use: rarely local and systemic usage Allergy, cold + Hypotension, shock (?)?) ```

Question 36

Xylometazoline, oxymetazoline, naphazoline, tetryzoline are:

Answer 36

mainly α 1 receptors --> vasoconstriction | local usage

Question 37

Phenylpropanolamine

Answer 37

mainly α 1 receptors ---> urinary bladder sphincter constriction! per os usage (empty stomach) side effects

Question 38

α adrenoceptor agonists: 8stk | α2 agonists: 4stk

Answer 38

``` Phenylephrine Xylometazoline, oxymetazoline, naphazoline, tetryzoline Phenylpropanolamine Ephedrine Amphetamine ``` α 2 agonists (sedato hypnotics) xylazine, detomidine, medetomidine, romifidine

Question 39

Ephedrine - receptors - use

Answer 39

``` nonspecific, direct and indirect effects - uses: tachyphylaxis CNS allergy, incontinence (p.o.) ```

Question 40

Nonspecific α antagonists | - drugs

Answer 40

- Phenoxybenzamine (urethra sphincter relaxation) long duration of action - Phentolamine - Tolazoline

Question 41

α1 antagonists

Answer 41

prazosine, doxasozine (urethra sphincter relaxation)

Question 42

α2 antagonists

Answer 42

atipamezole, yohimbine

Question 43

Nonspecific β antagonists

Answer 43

Propranolole Timolole SIDE EFFECTS

Question 44

Specific β 1 antagonists

Answer 44

Metoprolole | Atenolole