Antiadrenergic Drugs (Exam 1) Flashcards
Antiadrenergics
- Compound that inhibits the effects of exogenous catecholamines or adrenergic agonists
- Also includes Adrenergic blocking agents/drugs that deplete catecholamines (epi/NE/dopamine)
- Adrenergic alpha and beta blockers
Sympatholytic
Compound that inhibits the response due to sympathetic nerve stimulation on alpha or beta receptors
Adrenergic antagonists
Agents that inhibit or reverse the effects of NE and epinephrine (alpha and beta antagonists)
-osin
Alpha antagonist
-lol
Beta antagonist
Mixed Antagonists
labetalol (Trandate)
carvedilol (Coreg)
Receptor Affinity: ß1=ß2 ; a1>a2
doxazosin (Cardura)
prazosin (Minipress)
terazosin (Hytrin)
alpha1 selective antagonists
-direct relaxation of arterioles and veins
*Peripheral vascular disease and pheochromocytoma (Adrenal gland tumor)
High incidence of orthostatic/postural hypotension
afluzosin (Uroxatral)
*doxazosin (Cardura)
*prazosin (Minipress)
silodosin (Rapalfo)
tamsulosin (Flomax)
*terazosin (Hytrin)
- Benign Prostatic Hyperplasia
- Blockade of alpha1a receptor in prostate = smooth muscle relaxation in bladder neck and prostate (increasing urine flow)
*Note doxazosin, prazosin, and terazosin are also used to manage hypertension
What should you think when you see B2? How about B1?
B2 think lungs
B1 think heart
What are some of the major therapeutic adrenergic antagonists used for hypertension? What’s an important not to add on beta blockers in general?
Note: beta blockers in general are old medications and FDA-approved indications do not necessarily reflect current practice

What is the drug of choice for a hypertensive emergency (historically used for a cocaine overdose)? Why?
IV labetalol (Trandate)
- ß1 = ß2 and alpha blockade (antagonist)
- No unopposed alpha unlike other beta-blockers
How do certain beta blockers indicated for hypertension control act? (3)
- Decrease:
1) Heart rate
2) Renin release (BP decrease)
3) Myocardial contractility and cardiac output (block epinephrine)
What are certain beta blockers with an established mortality benefit for systolic heart failure? (reduced ejection fraction)

Which beta blockers have intrinsic sympathomimetic activity? What are these contraindicated for?
acebutolol (Sectral)
penbutalol (Levatol)
pindolol (Visken)
-Mycocardial infarction or angina
Which beta blockers have been shown to improve mortality, prevent cardiac remodeling/arrythmias, and reduce angina in patients with ischemic heart disease or recent MI?

Which beta blocker is a class 3 K+ channel blocker and also considered an anti-arrythmic?
sotalol (Betapace)
How can beta blockers be used for rate control in the treatment of supraventricular arrythmias such as atrial fibrillation?
Because they block conduction through AV node via ß1 blockade
*metoprolol (Lopressor/Toprol) is the most common for a-fib

What are specific examples of beta blockers used for glaucoma and what is their mechanism of action?
They decrease aqueous humor production by the ciliary body to decrease introcular pressure
*eye drop form

What are some miscellaneous uses of propranolol (Inderal) due to certain special properties?
Special properties: very lipophilic & penetrates the BBB; membrane stabilizing effects, which inhibits action potentials across membranes acting like a local anesthetic
-Migraine prophylaxis
-Essential (benign) tremor
Thyrotoxicosis
Antipsychotic-induced akathisia (movement disorder)
Off-labels: stage fright
What are some of the side effects of beta blockers?
- Bradycardia and heart block
- Bronchospasm
- Disturbance in glucose metabolism
- CNS
- Sexual
Which is worse for bronchospasm: selective or non-selective beta blockers?
Non-selective are worse (best to use a ß2-specific antagonist)
-At high doses, ALL beta blockers become non-selective
How can you tell if someone on beta-blockers is hypogycemic (or becoming hypoglycemic)?
They will have excessive sweating and and mood changes still; however, other signs and symptoms are inhibited
What are some of the CNS side effects of beta blockers?
Fatigue, drowsiness, depression, sleep disturbance, and nightmares
*Dependent on lipid solubility
What are the low lipid soluble beta blockers?
acebutolol, atenolol, betaxolol, bisoprolol, esmolol, nadolol, and timolol
What are the medium lipid-soluble beta blockers?
Labetalol, metoprolol, and pindolol
What are the high lipid soluble beta-blockers?
Carvedilol, nebivolol, and propranolol
Phentolamine (OraVerse)
Nonselective alpha blocker
- Vasodilation around area of injection
- Used for reversal of soft tissue anesthesia
*Side effect is marked orthostatic hypotension
phenoxybenzamine (Dibenzyline)
Non-selective Alpha blocker
- Long acting and irreversible
- Blocks both pre- and post-synaptic receptors causing vasodilation
(Pheochromocytoma sweating and hypertension)
*Side effect is marked orthostatic hypotension
Ergot Alkaloids effects
- Produced by a fungus that infects rye/other grains
- Gangrene of extremities, hallucinations, delirium, uterine stimulation/miscarriage
Affects alpha adrenergic receptors (coonstriction) seratonergic and dopaminergic receptors (hallucinations)
ergonovine (Ergotrate)
Control of postpartum/postlabortal hemhorrage
Alpha and seratonin agonist
methylergonovine (Methergine)
Used to induce uterine contraction and to control bleeding
Seratonin agonist
bromocriptine (Cycloset, Parlodel)
treatment of Parkinson’s disease (dopamie agonist)
ergotamine/dihydroergotamine
Migraine treatment (alpha vasoconstriction and stimulation of serotonin receptors)
*Often combined with caffeine in formulations to facilitate absorption
What is the toxicity of ergot alkaloids for:
- Acute use
- Chronic use
- Overdose
Acute use: GI disturbances (diarrhea/nausea/vomit)
Chronic use: gangrene of nose, finger, and ears due to severe vasoconstriction and prolonged vasospasm
OD: muscle contraction, hallucination, delirium, and convulsion
What is a contraindication to Ergot Alkaloid use?
Obstructive vascular disease and collagen diseases
(can cause connective tissue proliferation)
How many serotonin receptors have been cloned? What are the most common?
14
Most common:
-
5-HT1
- Brain
-
5-HT2
- Brain and peripheral tissue
- 5-HT3
- Chemoreceptive and vomiting centers in CNS/periph. sensory and enteric nerves
What are the effects of seratonin on the CV system?
Contraction of smooth muscles
Constricts most vascular beds
What are the effects of seratonin on blood platelets? Small intestine? CNS?
- Enhances platelet aggregation
- Increased intestinal motility
- Mood changes/cognition/sexual behavior/learning/memory/sleep/appetite/perception of pain/depression/anxiety
5-HT1B/1D Receptor agonists
Triptans
-Used to treat migraines by preventing vasodilation
Stimulation of these receptors ( presynaptic trigeminal nerve endings) inhibits the release of vasodilating peptide (Calcitonin gene related peptide/CGRP)
Contraindications: coronary/cerebral vasospasm; coronary artery disease or stroke
sumatriptan (Imitrex)
Selective Seratonin 5-HT1B/D agonist
migraine treatment
When are selective serotonin receptor agonists especially toxic?
When they are used in comnination with anti-depressants that increase serotonin levels! This can lead to Serotonin Syndrome
Seratonin Syndrome Management
- Mild
- Moderate
- Life Threatening
Mild: Observe 6 hours and Benzodiazepines (sedative)
Moderate: Admit to hospital/heart monitoring/Cyproheptadine
Life Threatening: ICU; Esmolol (IV ß1 agonist)
Symptoms of Serotonin Syndrome
- Mild
- Moderate
- Life Threatening
Mild: pupils dilated (mydriasis), shivering, sweating, and mild tachycardia
Moderate: Altered mental status, autonomic hyperactivity, and neuromuscular abnormalities
Life threatening: delirium, hypertension, hyperthermia, muscle rigidity, and tachycardia
CGRP Antagonists
Migraine specific and monoclonal antibodies (-mab suffix)
- Fremanezumab: attaches to CGRP receptor
- Galcanezumab: attaches to CGRP receptor
- Erenumab: blocks CGRP receptor
How many half lives before a medication’s effect is gone?
4-5
If drug A has a therapeutic index of 3 and drug B has a therapeutic index of 50, which would be the greatest safety concern?
Drug A (drug b is safer)
Which agency regulates safety and efficacy of drugs?
FDA
Which route of administration works the fastest?
Will a drug bound to plasma-protein have activity?
What are the parts of kinetics of drugs (pharmacokinetics)?
ADME
Absorption, Distribution, Metabolism, Elimination