Term
| Where can you find alpha one receptors and the specific functions? |
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Definition
1. Vascular smooth muscle - constriction
2. Heart - inc. intoropy, HR, g
3. Eyes - constriction => dilation
4. GI smooth muscle - relax
5. GU smooth ms and prostate - retention
6. Liver - Glcneogen, Glycogenolysis |
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Term
Alpha 2 receptors - where and what they do there?
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Definition
1. presynaptic neuron - autoreceptor function (A)
2. vascular smooth ms - constriction (B)
3. pancreativ beta cells - inhibit medulla secretions (C) |
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Term
| What is the rate limiting step of catecholamine synthesis? |
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Definition
| Convertion of Tyr to DOPA by "Tyrosine Hydroxylase" |
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Term
| What is the enzyme for tranfering catechomine into the vesicles and what Rx blocks it? |
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Definition
VMAT
- blocked by Reserpine (irreversible inhibition) |
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Term
| What is the enzyme for NE reuptake and what inhibits it? |
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Definition
NET
- inhibited by Cocaine and TCA
- resuts in increased NE activity |
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Term
| 4 examples of catecholamines? |
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Definition
1. Ep (stored in adrenal medulla until needed)
- b1=b2; a1>a2
2. NE (main SNS NT)
-a1=a2;b1=b2
3. DA
-D1=D2; b1>b2>a
4. Isoproterenol
- b1=b2>>>>>>>a |
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Term
| Example of alpha 1 selective agonist? |
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Definition
Phenylephrine
- nasal decongestant, eye drop for mydriosis
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Term
| Example of alpha 2 selective agonist? |
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Definition
Clonidine
alpha-methyldopa
- anti-hypertensive rx |
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Term
| Example of alpha (1 and 2) agonist? |
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Definition
Oxymetazoline
- vasocontriction
- decongestant + eye drop for redness |
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Term
Example of Beta 1 selective agonist?
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Definition
Dobutamine
- acute CHF and post-op support |
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Term
| Example of beta 2 selective agonist |
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Definition
Albuterol & terbutaline - short acting
Salmeterol - long acting
Bronchodilators
terbutaline - used as a uterine relaxant |
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Term
| Adverse effects of Adrenergic agonists - Peripheral and CNS |
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Definition
Peripheral:
1. HTN
2. Cardiac Ischemia
3. HF
4. Tachycardia
5. Cardiac arrhythmias
CNS:
1. Headache
2. Restlessness & hyperactivity
3. Tremor
4. Insomnia
5. Anxiety |
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Term
| What is the drug of choice for Anaphylactic shock? |
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Definition
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Term
| What is the drug of choice for bronchospasms? |
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Definition
Epinephrine
- Intermuscular works with in few mins
- Subcutaneos is bad |
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Term
| Which catecholamine causes Baroreceptor Reflex bradycardia? |
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Definition
Norepinephrine
- has a stronger vasoconstriction effect than EP
- also results in vasoconstriction in kidney
==> resultant increase in BP lead to baroreceptor refelx bradycardia
(not the Rx of choice, but can be used in shock) |
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Term
| What is the drug of choice for cardiogenic & septic shock? |
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Definition
Dopamine
- increase cardiac output (B1)
- increase blood flow to kidneys (D1 - vasodilation) |
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Term
| Two adrenergic agonists used as Nasal decongestants & eye drops |
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Definition
Oxymetazoline
- nasal decong
- eye drop for redness after swiming etc.
Phenylephrine
- nasal decong
- eye drop for mydriasis |
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Term
| Which rx can be used to prolong/suppress premature labour? how does it do it? |
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Definition
Terbutaline
- relaxation of the uterus (beta 2) |
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Term
What are two Mixed acting adrenergic agonists?
What are they used for and how do they work? |
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Definition
=> Mixed acting adrenergic agonists stimulate NE release while activating adrenergic receptors them selves:
1. Ephedrine
- for persistent hypotension and to dec. asthma attacks
-banned due to lethal CV rxns
2. Pseudoephedrine
- Nasal decongestant
- side effects include insomnia, tach, HTN and rebound cong
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Term
| What are the different Indirect Acting Adrenergic agonists? |
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Definition
Storage inhibitors:
1. Tyramine (wine and cheese - no clinical use)
2. Amphetamines (release agent)
3. Methylphenidate (release agent)
- release agent displace NE from vesicles => inc. secretion
- used for narcolepsy and ADHD
Re-uptake inhibitors: (inhibits NET)
1. Cocaine
2. TCAs
MAOIs: (depression) - watch out for wine+cheese
Iproniazid, selegilina, phenelzine |
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Term
| what are the adverse effects of alpha and beta antagonist Rx? |
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Definition
Alpha antagonism:
1. Postural hypotension
2. Sexual dysfunction
3. Reflex tachycardia
Beta antagonism:
1. CNS
2. Sedation
3. Depression
4. Periphary
5. Bronchoconstriction
6. Bradycardia
7. Reflex vasoconstriction
8. Hypoglycemia
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Term
| What is the drug of choice for cardiac arrest |
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Definition
Epinephrine
- watch for reflex bradycardia |
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Term
| What are alpha 1 selective antagonist drugs? |
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Definition
1. Prazosin, Terazosin, Doxazosin
- prevents peripheral vasoconstriction => dec. BP
- used in HTN and CHF
2. Tamsulosin
- alpha 1 a
- used in Benign Prostate Hyperplasia |
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Term
| What is an alpha 2 selective antagonist? |
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Definition
Yohimbine
- alpha 2 autoreceptor blocked => inc. NE release
- for Erectile Dysfunction
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