Lodge 2 Flashcards
Drugs: Prazosin, terazosin, doxazosin, tamsulosin, and alfuzosin
Alpha blockers
Responses to Alpha blockers
Vasodilation (blood vessels of the skin, viscera, mucous membranes)
Uses for Alpha blockers
- Hypertension
* Benign Prostatic Hyperplasia (enlarged prostate)
a1 Adrenergic Antagonists – Hypertension
a1-adrenergic antagonists relax smooth
muscle and decrease TPR.
a1 Adrenergic Antagonists – BPH
•Tamsulosin(Flomax): a1-adrenergic antagonists relax smooth muscle in the prostate and bladder neck decreasing the degree of blockage of urine flow (treat symptoms).
• Side effects:
- dizziness when standing (due to vasodilation).
- inhibits ejaculation or causes retrograde ejaculation
Side effects of directly-acting antagonists: the alpha blockers
- Orthostatic hypotension
- Tachycardia
- Vertigo
- Sexual dysfunction
Uses for B blockers
tx of hypertension, ischemic heart disease, congestive heart failure, and certain arrhythmias
Uses for Propranolol – prototypic non selective b Blocker
- Hypertension
- Migraine
- Hyperthyroidism
- Angina pectoris
- Myocardial infarction
Side effects of directly-acting antagonists: propranolol – prototypic non selective b Blocker
- Fatigue
- Bronchoconstriction
- Sexual dysfunction
- Arrhythmias
Acetylcholine is released from parasympathetic postganglionic neurons as well as ALL _______ neurons
preganglionic & somatic
Acetylcholine Synthesis occurs in nerve terminal and ______ is the rate limiting step.
Choline uptake
Acetylcholine Inactivation
- Hydrolyzed by acetylcholinesterase (AChE) in the synaptic cleft to form choline
- Recycled
- Terminated by pseudocholinesterase, widely distributed throughout the plasma
- Atony of the bladder
- Atony of the GI tract
- Myasthenia gravis (↓ muscle tone) - Intoxication by Ach antagonists
- Glaucoma
- Alzheimer’s Disease
Therapeutic uses of AChE inhibitors
Reversible AChE Inhibitors include…
- Physostigmine
- Neostigmine
AChE Inhibitors can be used to treat _______ by increasing synaptic ACh.
Myasthenia Gravis
______ is a nicotinic agonist that is NOT degraded by Acetyl cholinesterase
Suxamethonium
______ (short duration AChE inhibitor) used to distinguish between “myasthenic” and “cholinergic” crisis in patients
Edrophonium
AChE Inhibitors can be used to treat _____ by restoring loss of function and not altering progression of the disease.
Alzheimer’s Disease
Tacrine, donepezil, rivastigmine, and galantamine
AChE inhibitors
Cholinergic Receptors:
- agonist
- as many as 12 sub-types
- ligand-activated cation channels
Nicotinic
Cholinergic Receptors:
- agonist
- 5 sub-types
- G-protein coupled (7-TM)
Muscaranic
_______ are the principle cholinergic receptor in skeletal muscle and autonomic ganglia (BOTH sympathetic and parasympathetic) and are ligand-gated cation channels
Nicotinic receptors
Full agonist at Nicotinic Receptors and has both central and peripheral effects
Nicotine
• CNS stimulant - Arousal - Increases mental performance • Rewarding (activates DA system) • Addictive
Nicotine Effects (central)
- Sympathomimetic (Increase BP and Heart Rate)
- Nicotine stimulates nicotinic receptors on adrenal medulla leading to epinephrine release
Nicotine Effects (periphery)
– A partial agonist at central a4b2-nicotinic receptor
– Possesses 50% of the intrinsic activity of nicotine – Prevents the binding of nicotine
varenicline (Chantix)
______ are the principle cholinergic receptor at autonomic ganglia (BOTH sympathetic and parasympathetic)
Nicotinic receptors
Because ganglonic antagonists block ______ function, the effect of these drugs depends upon the dominant tone in the organ system.
BOTH parasympathetic and sympathetic
Nicotinic Receptor Drugs: no longer of use for regulating autonomic functions (non specific)
NN (Ganglion)
Nicotinic Receptor Drugs: effects at muscles useful for paralysis during surgery
NM (NMJ)
Nicotinic Receptor Drugs: Smoking cessation, also promising advances with SELECTIVE ligands (i.e. Analgesia, Alzheimer’s, schizophrenia)
NN (Brain)
Muscarinic receptors are localized to ________.
parasympathetic effectors
________ are the principle cholinergic receptor in smooth muscle, cardiac muscle and glands.
Muscarinic receptors
Muscarinic Agonist examples
- Bethanechol (non-selective)
- Cevimeline (M3)
- Atropine (non-selective)
- Ipratropium/tiotropium (M)
Use of Cevimeline
- Muscarinic agonist (mainly M3)
- Parasympathetic stimulation increases salivation
- Used in dentistry to treat severe Xerostomia (dry mouth)
Side effects of Cevimeline
sweating, urination, stuffy nose, lacrimation, and abdominal pain
Use of Atropine
Decrease respiratory secretions as an adjunct for anesthesia
Effects of Atropine
- **Secretion **– Potently inhibits glandular secretion –particularly salivation (can be used in dental setting)
- Eye – Persistent mydriasis (dilation) lasts 7-14 days
- GI – Can be used as anti-spasmodic to reduce GI motility.
- Urinary – reduce hyper-motility states of the urinary bladder, occasionally used in children.
- Cardiovascular – Bimodal. Low doses inhibit presynaptic M1 receptors and increase Ach leading to bradycardia. High doses block M2 in SA node and increases heart rate.
Use and effects of Ipratropium/ tiotropium
- Used as second-line therapy for asthma (first line Albuterol– b agonist)
- Therapeutic effects are specific due to inhalational application
_________ (i.e. Cevimeline) will stimulate salivation, however due to their side effects, muscarinic agonists are not widely used to treat this condition as there are satisfactory masticatory stimulants and artificial saliva products available OTC.
Muscarinic agonists
Patients taking parasympathomimetics (e.g., post-operative GI problems or glaucoma) should never be treated with _______ to reduce the flow of saliva.
anti-cholinergic drugs
