Adrenergic Drugs Flashcards

1
Q

Sympathomimetics

A

Adrenergic Agonists

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Sympatholytics

A

Adrengergic antagonists

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

a1 in Eye

A

Contraction of the radial muscle of iris (mydriasis)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

a1 in Arteries, Vein

A

Vasoconstriction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

a1 in urinary tract of male

A

Constriction of sphincter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

a1 in vas deferens

A

Ejaculation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

a2 in pre-syaptic nerve terminals

A

NT release inhibition

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

a2 in CNS

A

Sympathetic outflow to vessel inhibition

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Classes of Adrenergic Agonists

A
Direct-acting
-Catecholamines
-Non-catecholamines
Indirect acting
-Indirect only
-Mixed activity
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Base structure of agonist

A

Phenylethylamine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Importance of catecholamine structure

A

3,4 hydroxylation of phenyl group (catechol group) improves affinity for maximal alpha, beta receptors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Factors affecting affinity for agonists

A

2 carbons b/w aromatic ring and amino group affords greatest sympathomimetic activity
Substitution of alkyl group on the amino group tends to increase beta activity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Features influence bioavailability/metabolism

A

Absence of one or both -OH on phenyl increases oral effectiveness
Substitution on alpha-carbon makes the compound more resistant to MAO
Substitution of -OH group on beta carbon decreases lipid solubility and decreases CNS actions, increases peripheral activity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Metabolism of catecholamines

A

Metabolized by MAO and catechol-O-methyltransferase
Not effective by oral administration
Must be given parenterally to avoid liver
Short half life (minutes)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Predominant role of catecholamines

A

CV actions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Norepinephrine - Receptor selectivity

A

Alpha1/2,Beta1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Norepinephrine - CV Effects

A

Alpha-1 primarily
Increases peripheral vascular restriction (PVR)
Increases mean BP
Reflex towards bradycardia (Decreased HR)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Norepinephrine - Therapeutic uses

A

Vasoconstrictor in certain acute care situations (shock)

Elevate BP during reduced sympathetic tone (examples: neurological injury, spinal anesthesia)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Epinephrine - Receptor selectivity

A

All major receptors (alpha-1/2,beta-1/2)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Epinephrine - CV Effects

A

Increase HR, contractile force, cardiac output
Increase systolic BP, decrease diastolic BP
Vasoconstriction except in skeletal muscle beds so net PVR decrease (Beta-2)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Epinephrine - Respiratory effects

A

Bronchodilation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Epinephrine - Metabolic effects

A

Hyperglycemia

Increase free fatty acids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Epinephrine - Therapeutic uses

A

Hypersensitivity reaction - Allergies, bronchoconstriction
Increase duration of action of local anesthetics
Bradyarrhythmias
Opthalmic uses - Mydriatic so decreases hemorrhage and conjunctival congestion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Dose dependence of Epi on PVR

A

Low concentration of epi results in B2 vasodilation
High concentration of epi, B2 is saturated so binds to A1 resulting in vasoconstriction
At high concentration CV effects becomes the same as norepi

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Isoproterenol - Receptor selectivity

A

B1/2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Isoproternol - CV Effects

A

Decrease PVR
Increase HR, contractile force, CO
Decrease mean BP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Isoproternol - Respratory effects

A

Bronchodilation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Isoproternol - Therapeutic uses

A

Emergency use for treatment of bradycardia or heart block

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Dopamine - CV effects

A
Low dose (0.5 ug/kg/min)
Renal dose - Dilation of renal and mesenteric arteries, decreasing PVR, increase renal flow (D1 receptor)
Intermediate dose (5-10 ug/kg/min)
Cardiac dose - Increases HR, contractile force, CO (D1 + B1)
High dose (10-20 ug/kg/min)
Pressor dose - Vasoconstriction and increased PVR (D1 + B1 + A1)

Used in coronary care settings

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Dobutamine racemic effects

A

(-) : A1 agonist, B agonist
(+) : A1 antagonist, B agonist
Net result: B1 agonist

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Dobutamine CV effects

A

Increased HR, contractility, CO

Minimal change in PVR and BP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Dobutamine Therapeutic uses

A

Short-term treatment of cardiac decompensation (cardiac surgery, heart failure, MI)
Cardiac stress testing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

B1 - Heart response

A

Increased HR, contractile force, AV nodal conduction velocity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

B1 - Kidney response

A

Renin release

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

B2 - Artery (Skeletal, cardiac muscle)

A

Dilation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

B2 - Bronchi

A

Dilation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

B2 - Skeletal muscle

A

Glycogenolysis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

B2 - Liver

A

Glycogenolysis, gluconeogenesis

39
Q

D1 Receptor

A

Arteries (kidney, mesentery) - Dlation

40
Q

Methyldopa - Metabolism and receptors

A

Orally active pro-durg
Metabolized in nerve terminals to alpha-methyldopamine, alpha-methylnorepi, which are stored and released with nerve stimulation
A2 receptor agonists, and stimulate central A2 receptors to reduce sympathetic outflow

41
Q

Methyldopa - Major therapeutic use

A

HTN

Especially gestational HTN, has no effect on fetus

42
Q

Methyldopa - Side effects

A

From CNS penetration

Sedation, dry mouth, edema, rebound HTN if discontinued

43
Q

Where does methyldopa target for decreased sympathetic outflow?

A

CNS

PNS would not have the CV effects

44
Q

Phenylephrine - Target and CV effects

A

A1 adrenergic recepetor agonist
Increase systolic and diastolic BP, PVR
Reflex decrease in HR
Decrease flow in most vascular beds

45
Q

Phenylephrine - Therapeutic uses

A

Opthalmic: Mydriatic
Nasal decongestant: Oral or nasal spray
Adminster with local anesthetics to increase duration of action
Treatment of HTN

46
Q

Similar drug to phenylephrine

A

Midodrine

47
Q

Clonidine - Target

A

A2 adrenergic receptor

Orally active

48
Q

Clonide - Therapeutic Use, CV effect

A

Anti-HTN by CNS: Activates central A2 receptors decreasing sympathetic outflow (Hypothalamus and medulla)
Prolonged BP lowering
Decreases PVR, HR, CO

49
Q

Clonide - Adverse effects

A

Dry mouth, sedation (50% of patients), edema, rebound HTN

50
Q

Albuterol - Target and kinetics

A

B2 adrenergic receptor agonist
Short acting: 3-6 h after inhalation
Primarily inhalation, but also available as oral tablet

51
Q

Albuterol - Therapeutic use

A

Bronchodilator - Asthma

52
Q

Albuterol - Adverse effects

A

Tremor, anxiety, tachycardia

53
Q

Salmeterol - Target and kinetics

A

B2 adrenergic receptor agonist
Long duration of action: 12h
Aryl alkyl (11 carbons) substitution makes the compound lipophilic

54
Q

Salmetrol - Therapeutic use

A

COPD, nocturnal or persistent asthma

Too slow for acute bronchospasm (asthma attack)

55
Q

Tyramine - Function

A

Indirect only agonist
In absence of MAO inhibitors - Metabolized in liver, no effect
In presence of MAO inhibitors - Reaches axon synapse and encourages monoamine release (dopamine, norepi, epi), can lead to HTN

56
Q

Example of mixed acting sympathomimetics

A

Amphetamine
Methamphetamine
Ephedrine/Pseudoephdrine

57
Q

Amphetamine - Target and effects

A

CNS stimulant in addition to peripheral alpha/beta action
Depresses appetite
Effective after oral administration (long half-life)
Releases NE from adrenergic nerves, weak direct alpha/beta agonist, competes with NET

58
Q

Amphetamine - Therapeutic uses

A

Narcolepsy

ADD

59
Q

Ephedrine - Targets and metabolism

A

Direct agonist of alpha/beta receptors, release NE
Orally active
CNS stimulation

60
Q

Ephedrine - Usage

A

Previously for asthma

Found in some herbal supplements but now banned by FDA

61
Q

Pseudoephedrine - Targets

A

Direct A1 agonist, minor B2 activity

Less CNS stimulation

62
Q

Pseudoephedrine - Therapeutic use

A

OTC Nasal Decongestant (Oral, Spray)

Sale is now limited due to illegal use in synthesis of methamphetamine

63
Q

General Side Effects/Toxicity of Sympathomimetics and Receptor cause

A

Throbbing headache - Alpha (vasoconstriction)
Increased heart rate, palpitations - Beta
Pericardial pain - Beta (Angina due to increased HR)
Cardiac arrhythmias - Beta
Cerebral hemorrhage - Alpha (Increased BP)
Restlessness, anxiety - Both

64
Q

Definition of Adrenergic Neuron Blockers

A

Agents that block the synthesis, storage or release of norepinephrine

65
Q

Guanethidine and Guanadrel - Target and Kinetics

A

Orally active, long acting
Taken up into adrenergic nerves via NET
Do not penetrate into the
Inhibit NE relase and deplete neuronal amine stores

66
Q

Guanethidine and Guanadrel - Therapeutic use and side effects

A

Therapeutic for HTN

Can cause orthostatic HTN, male seual dysfunction, diarrhea, muscle weakness, edema

67
Q

Reserpine - Target and Kinetics

A

Diffuses into adrenergic neurons and depletes NE stores by inhibiting VMAT2

68
Q

Reserpine - Therapeutic use and side effects

A

Therapeutic: HTN
Can cause sedation, depression (suicidal tendencies), Diarrhea, Orthostatic hypotension, Increased gastric acid secretion

69
Q

Definition of Adrenergic Receptor Antagoinists

A

Agents whose effects are produced by inhibiting either alpha and/or beta receptors
Blocks both endogenous and exogenous catecholamines
Targets specific receptor response
May affect NE release from adrenergic neurons

70
Q

Non-selective Alpha Adrenergic Receptor Antagonist

A

Both alpha receptors

71
Q

Overview of phenoxybenzamine

A

Irreversible non-selective alpha antagonist
Orally active, long duration
Produces vasodilation proportional to degree of sympathetic tone

72
Q

Overview of phentolamine

A

Competitive, reversible non-selective alpha agonist
Orally active, shorter duration (2-4 h)
Block can be overcome (competitive kinetics)

73
Q

Therapeutic use of non-selective alpha antagonist

A

HTN (phentolamine only) - Cases refractory to other treatments, an only in combination with other agents
HTN with pheochromocytoma (Both)
Reverse or shorten duration of anesthesia produced by a combination of local anesthetic and sympathomimetic (phentolamine)

74
Q

Side effects of non-selective alpha antagonist

A

Tachycardia
Edema
Orthostatic HTN

75
Q

Prazosin - Overview

A

A1 Competitive Adrenergic Antagonist
Orally active
Little blockade of pre-synaptic A2 receptors so minimal tachycardia, CO increase
Decrease vascular tone in resistance (aa.) and capacitance (vv.) beds
Produces favorable effects on lipid profile

76
Q

Prazosin - Therapeutic uses

A

HTN
Short-term treatment of CHF
Urination problems with benign prostatic hyperplasia (BPH)

77
Q

Prazosin - Side effects

A

First dose phenomenon - HTN and syncope 30-90 mins after 1st dose
Orthostatic hypotension
Edema

78
Q

Tamsulosin - Overview

A

Orally active A1 adrenergic receptor antagonist (favors A1A in prostate over A1B in blood vessels)

79
Q

Tamsulosin - Therapeutic use

A

Urination problems with BPH

Little effecton BP or HTN

80
Q

Overview of beta-blockers

A

Beta-blocking selectivity
Minor actions: Partial agonists, local anesthetic or quinidine-like activity, some A1 selective as well, can be vasodilating

81
Q

Location of clinically relevant beta receptors

A
Heart
Bronchial Smooth Muscles
Kidney (renin)
Skeletal muscle
Blood vessels supplying skeletal muscle
Liver
82
Q

Propranolol - Overview

A

Non-selective beta competitive, reversible antagonist

Orally active - substantial first-pass metabolism

83
Q

Propranolol - Therapeutic uses

A
HTN
Angina pectoris
Cardiac arrhythmias
Acute MI
Pheochromocytoma
Migraine prophylaxis
84
Q

Propranolol - Side effects

A

Cardiac depression, bradycardia/heart block
Bronchoconstriction
Sedation, impotence, nightmares

85
Q

Propranolol - Careful in patients with

A
Asthma
CHF
Bradyarrhythmias, AV bloc
Insulin-dependent diabetes: hypoglycemic episodes
Hypotension
Vasospastic angina
86
Q

Timolol - Overview

A

Non-selective beta adrenergic receptor antagonist

Orally active

87
Q

Timolol - Therapeutic uses

A

Similar to propranolol
Also widely used in the treatment of wide-angle glaucoma
Decreases aqueous humor formation by the ciliary epithelium, leading to decreased intraocular pressure
Does not affect pupil size or accomodation
Administered as eye drops
Small amounts can be absorbed into sytemic circulation

88
Q

Metoprolol - Overview

A

B1-selective competitive, reversible antagonist
10-fold selectivity for B1 at low doses
Cardioselective, 2nd generation beta-blocker

89
Q

Metoprolol - Therapeutic uses

A

Similar to propranolol

Also used for CHF

90
Q

Metoprolol - Side effects

A

Similar to propranolol

Less bronchoconstriction

91
Q

Atenolol - Overview

A

B1-selective, orally active, once per day dosing
Does not penetrate into CNS, less side effects
Therapeutic similar to propranolol except for migraine prophylaxis

92
Q

3rd Generation Beta Blockers

A

Antagonists with additional CV effects

93
Q

Labetolol

A

Competitive, reversible antagonist of a1, beta

Therapeutic use for essential HTN (orally) and HTN crisis (IV)

94
Q

Carvedilol

A

Competitive, reversible antagonist of a1, beta

Therapeutic use for CHF, acute MI