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Week 2: Pharmacology

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What is phase 1 block?
overstimulation of Nicotinic (cholinergic)stimulation.
What can block the nicotinic receptors at the skeletal muscle?
1. Tubocurarine
2. Trimethaphan
1. What is the mechanism of Vasodialation of endothelial cells by muscarinic cholinergic agonist?
1. Release of NO (activation EDRF)
Alpha are always exciting except for?
GI tract
Location of alpha 1 and alpha 2?
1. Mostly postjunctional
2. Mainly prejunctional (except postjunctional at plt, smooth muscle, and adipocytes)
what are the primary effects of Beta 1 adnergic receptors?
1. Heart rate
2. Lipolysis
3. Renin secretion
Isoproterenol has a greater effect on what receptor over Epi and NE?
Beta 1 (Iso also stimulates Beta 2)
Function of Beta 2 adrenergic receptors?
1.Vasodilation
2. Bronchial smooth muscle relaxation
3. GI relaxation
Bethanechol, Carbachol and Pilocarpine are all what?
Which is the odd one out of the three? and why
1.Muscarinic agonists
2. Carbachol- also stimulates both Muscarinic and Nicotinic
Effects of Parasympathetic in the Eyes?
1. Miosis
2. Reduces intraocular pressure
Drugs that will cause Miosis and reduce intraocular pressure?
Bethanechol, carbachol
most importantly Pilocarpine
What is the effects of alpha-adrenergic agonist on the cilliary muscle?
None (it will contract just the iris radial m.causing mydrasis)
What are the therapeutic effects of most Parasympathetic drugs?
Eyes
GI
Urinary tract
1. Eyes - Glacoma (increase incidence of caratact)
2. GI - improves peristalsis (esp after surgery, gastric atony and postoperative abdominal distention)
3. Urinary tract - Improves urination
4.
What parasympathetic M. agonist can be used to diagonose Brochial hypersensitivity and asthmatic condition (constrict the bronchials)
Methacholine
What primary drug is used for the treatment of Open-angle glaucoma?
Any others used?
1. Pilocarpine
2. Carbachol is used if pilocarpine is ineffective
3. B-adrenergic receptor antagonist (timolol and betaxolol)
Or CA inhibitor - Acetazolamide
Ach agonists are contraindicated in what conditions?
1. Asthma
2. Heart disease
3. Peptic ulcer (increase secretions)
4. Parkinsonian disease (increase Ach)
What is Edrophonium?
Short acting AchE inhibitor. Used in the Tensilon test for Mys. Gravis diagnosis
Difference between Neostigmine and Physotigmine?
What are they?
1.Neostigmine - poorly absorbed (GI, negligible in CNS)
Physotigmine - Well absorbed (GI,Enters CNS)

2. Reversible Long acting AchE
Name 2 irreversible Long acting AchE inhibitor?
1. Echothiophate and Isoflurophate

Echo is poor absorbed
Isoflurophate is highly lipid solube and well absorbed even in skin
Name the antidote for insecticide or nerve gas poisoning (Ach E reactivator)?
Pralidoxime (but ineffective in CNS)
What parasympathetic drugs cause mydrasis (pupil dilation) and cycloplegia(loss of accomodation and paralysis of ciliary muscle)?
Muscarinic -receptor antagonist e.g Atropine,Scopolamine et.c
Is Atropine short or long acting - Muscarinic Receptor anatgonist?
Long acting
For each organ system list the therapeutic importance of Muscarinic Antagonist
Eye
Heart
Stomach
GI
Urinary
CNS (2 things)
1. Eye - Opthalmoscopic exam
2. Heart- Acute MI with bradycardia
3. Stomach - Treat peptic ulcer (reduce acid) but there are better drugs now
4. GI - mild diarrhea
5. Treat Urinary Urgency
6. Parkinsonian and Motion Sickness
what is difference between Tubocurarine, succinylcholine and Trimethaphan?
What do they all have in common?
1. Succinylcholine is an Nictotinic depolorizing agonist
Tubocurarine and Trimethaphan are both Nicotininc antagonist
2. All are Neuromuscular blockers (Trimethaphan - blocks just the ganglionic nicotinic Receptors)
What is another drug you can use for Ach E inhibitor poisoning (aside from AchE regenrator Pralidoxime)?
Atropine (Muscarinic blocker)
Reversibly what classes of drugs can be used to treat Muscarinic antagonist (Atropine, scopolamine) overdose?
Physostigmine(tertiary, e.g atropine) and Neostigmine (quaternery)
what ANS system does Ganglionic block drugs (ganglionic nicotinic antagonist)?
Can they be used for what? may cause what?
Name a drug with this properties?
1. Non depolarizing blockade of both P-ANS and S-ANS
2. Decrease blood pressure (by reducing sympathetic tone in vasculature)
3. Trimethaphan
Trimethaphan - is what kind of drug?
Simulates the release of ------ and causing -----, -----, ----.
1. Peripheral ganglionic nicotinic blocker.
2. Histamine, and causes Flushing, dizzines and headaches
Name types of muscle relaxants and give a few drug examples?
1. Neuromuscular junction blocker - Ach R antagonist
A. Depolarizing:Succinylcholine
B. Non-depolarizing: Tubocurarine

2. Spasmolytic drugs - mimic GABA in the CNS (Benzodiazapine) or some drugs interfere with release of Ca2+ in skeletal muscle (Dantrolene)
Tubocurarine, Atracurium, mivacurium, Pancuronium,Vecuronium and Rapacuronium are all -------- ?
Non-depolarizing Neuromuscular blocking drugs (muscle paralysis)
Name a drug - that will be great for muscle paralysis (but note they have to be on a mechanical ventilator or else respiratory failure)?
Depolarizing or Non-depolaring neuromuscular blockers.
What is the problem with Neuromuscular blocking drugs?(hint not at NMJ)
1. Histamine release: may cause vasodialation and bronchospasms
2. Prolonged apnea (paralysis)
Name two drugs that may potentiate the effects of NMJ (nicotinic) blockers? (because they inhibiting Ach release)
1. Aminoglycoside
2. Lincomycin
Is Succinylcholine broken down by AchE?
1. Yes but much slower.
Describe the reversal of succinylcholine blockade
1. Phase 1: due slow metabolization of succinylcholine
Muscle is depolarized(inital contraction), then flaccid paralysis

2. Phase 2: In repolarization, Ach still has no effect on the AchR.
Adverse effects of succinylcholine?
1. Hyperkalemia
2. Malignant hyperthermia (likely to occur than succinylcholine than Halothane)
Tx of Malignant hyperthermia?
Dantrolene
1. Name a spasmolytic drugs?
2. Best used for?
3. Name their Mechanism and primary target site?
1. Dantrolene and Baclofen
2. Spasms (seen in cerebral palsy, MS, stroke)
Muscle paralysis: Malignant hyperthermia
3. Ca2+ release in SR(dantrolene)and GABA-receptor (Baclofen)
Benzodiazepine also fall in this group (their main func is sedation and antianxiety)
Properties of beta 1 receptors?
increase the rate and force of heart contractions (by increasing the conduction in the AV node and lowers refractory peroid).
Name a spasmolytic drugs? Best used for? Name their primary target site?
1. Dantrolene and Baclofen
2. Spasms (seen in cerebral palsy, MS, stroke)
Muscle paralysis: Malignant hyperthermia
3. Ca2+ release in SR(dantrolene)and GABA-receptor (Baclofen)
Benzodiazepine also fall in this group (their main func is sedation and antianxiety)
Name drugs used to reduce intraocular pressure by the reduction of aqueous humor production?
Epinephrine and B-receptor antagonist
Why at low doses of epinephrine do we not get reflexive tachycardia?
1. Increase in Heart rate (Beta1) and vasodilation (Beta1 -reduction in TPR)
= No change in mean blood pressure

(HR increased, increased systolic, low diastolic)
Is NE used therapeutically?
Nope - not really

(has less beta2 activity - so increase TPR and increase diastolic)
Name the main Beta1 agonist?
Isoproterenol and Albuterol (same effect on Beta2)
Name the main 3 Beta non-selective agonist drugs?
1. Isoproterenol
2. Albuterol
3. Dobutamine
Why is albuterol great for asthma?
Name other drugs like it?
1.Because it works mostly on the Beta2 receptors (lungs and blood)
Beta 2agonist

2. Terbutaline (emergency drug for status asthmaticus), Albuterol
Distinguish the potency of each drug on Beta 1 vs Beta 2
Dobutamine
Isoproterenol
Albuterol (Terbutamine)
Dobutamine: B1>B2
Isoproterenol: B2=B1
Albuterol (Terbutamine): B2>B1
Name a common alpha-adrenegic agonist and function?
Potency is greater for which alpha receptor?
1.Phenylephrine
2. Increase TPR by vasoconstriction
2. a1>a2
What is Clonidine? The clinical effect of this drug?
1.alpha2 prejunctional agonist (reduces the release of NE)
2. Lower BP
What drug will you like to use in short-hypotensive emergencies?
1. Norepinephrine
2.Epedrine
What drug will you like to use in Cardiogenic or septic shock? Why?
1. Dobutamine
2. Dopamine

- Increases CO,HR (B1), low vasoconstrictive
- Dopamine especially for the renal perfusion (D1).
What Catecholamine might you use for the treatment of anaphylactic shock?Why
1.Epinephrine
2. Reverse the hypotension and angioedema and maintain BP
What Drug might you use for Congestive heart failure?
Dobutamine (apparently it stimulates B1 but the contractility property as opposed to the Heart Rate as seen with Isoproterenol)
For Temp. emergency treatment of cardiac arrest and heart block (Stokes-Adams syndrome)? Why
Isoproterenol and Epinephrine because they increase ventricular automaticity and rate and increase AV conduction via B1
What drug is used for the diagnosis of Horner's syndrome?
Hydroxyamphetamine (miosis, anhydrosis)
What drug can be used to relax the Uterus and suppress premature labor?
Terbutaline (beta2 agonist) and Ritodrine
Name some alpha antagonist? Main therapies?
1. Phentolamine (a1=a2)
2. Prazosin (a1)
3. Phenoxybenzamine (irreversible a1 antagonist)

A. Hypertension
B. Pheochromocytoma
Difference between Phentolamine, Phenoxybenzamine (a) and Prazosin, Terazosin,doxasin (b).
a.The former are non-selective alpha antagonist
b. a1 selective antagonist
What drugs will you use to treat essential hypertension, urinary rentention in BPH and Raynaud's phenomenoma?
Prazosin, Terazosin and Doxazosine
(all a1 selective antagonist)

Relax the bladder, vasodilated the blood vessels peripherally
What is a key side effect of prazosin, terazosin and doxazosin?
Postural hypotension
What are the cardiovascular effects of Beta-antagonist?
1. Lower blood pressure
A. reduce HR
B. Shorten AV node time and supress automaticity
C. May Increase TPR
D. Reduce Renin release
What are the respiratory and ocular side effects of Beta antagonist?
1. Increase airway resistance
2. Reduce intra ocular pressure (Timolol used for glaucoma)
What are the Endocrine and metabolic side effects of Beta antagonist?
Why should we becareful with the use of propanolol in diabetics?
1. Decrease lipolysis
2. Decrease Gluconeogenesis (may increase the hypoglycemic effects of insulin)
3.Propanolol should be used carefully with diabetics. May mask tachycardia due to hypoglycemia
What drug long-term treatment of hypertension?
1. Propranolol (not useful for hypertensive crisis)
With other drugs -diuretics and low salt diet
What drug is used to treat Supraventricular and ventricular arrhythmias?
Propanolol
1.Hexamethonium is what type of drug?
2.Why would Hexamethonium not cause Reflex tachycardia?
1. Nicotinic antagonist
2. Will cause vasodilation but also inhibit the baroreceptor functions.
What drug prevents the reuptake of choline in cholinergic cells?
Hemicholinium
What drug prevents the conversion and packaging of Dopamine to Norepinephrine - in noradrenergic nerves?
Reserpine
What drug inhibits the release of NE? What drug cause the release of NE?
What drugs (2) blocks the reuptake of NE?
1. Guanethidine
2. Amphetamine

3. Cocaine and TCA (tricyclic antidepressants)
What the Si/Sx of AchE inhibitor poisioning? DUMBBELSS
Diarrhea and Urination
Miosis and Bronchospasm
Bradycardia and Excitated skeletal m.
Lacrimation and Sweating and Salivation
Which Diuretics cause
Acidosis?
Alkalosis?
1. Acidosis: Loop diuretics and Thiazides

2. Alkalosis: Carbonic anhydrase and K+ sparing diuretics
What drugs are similar in mechanism to Thiazides but are more potent?
How may they be better than thiazide?
1.Quinazlinones and Indolines
2. May be effective in the presence of some renal impairment
Summary of the therapeutic benefits of thiazide?
1. Prefered Tx: HTN in with nl renal func
2. Ca2+ stones: idiopathic hypercalciuria
3.Diabetes insipidus
4. Combo (edema,cirrhosis or nephrotic)
What type of diet is recommended for a patient on thiazide?
To avoid what Six/Sx of hypo-K,Hypo-Na,Hypo-Cl?
1. Diet high K+
2. CNS disturbances, cardiac arrhythmias
and increased sensitivity to digitalis
Does thiazide help with Gout Sx?
No, may increase Urate serum levels
What is the effect of thiazide in patients with diabetes?
May cause hyperglycemia
Give me an example of a "high ceiling diuretic"
Loop diuretic
1.What transporter is blocked by loop diuretics and location of action?
2. What key electrolytes are lost?
3.Clincially used for?
1.Na+,K+,2Cl- of the Thick ascending limp of loop of henle.
2. Na,K,Cl and Ca2+ and Mg+
3. Edema,HTN,Hyper-Ca2+
Loop diuretics causes dose -related ototoxicity - So with this property what will be a bad combination with loop diuretic?
Loop diuretic(furosemide, erthacryin) and Aminoglycosides
Name the 2 types of K+-sparing drugs and examples of them?
1. Aldosterone inhibitor-spirolactone
2. non-Aldosterone inhibitor - Amiloride and Triamterene
What are the adverse effects of all the K+ sparing agents?
Spirolactone-specific side effects?
1. Hyper-K
2. Hyper-K, Endocrine effects (gynecomastia, antiandrogen efxs)
Location of receptor of adolsterone and spirolactone?
Location of the receptor for Amiloride and Triamterene?
Both in the cortical collecting tubule.
What electrolytes are involved when Spirolactone is used?
K and H secretion is prevented
Na reabsorption is prevented


Serum pic: Hyper-K, Metabolic acidosis, and Hypo-Na
Mechanism of Amiloride and Triamterene?
Prevents just Na+ reabsorption and prevents K+ excretion
Name the drug used for glaucoma, Urinary alkalinization, metabolic alkalosis and altitude sickness?
Carbonic Anhydrase (sulfonamide derivatives)

CA prevents the exchange of H+, with Na+ and HCO3-
Name an important Carbonic Anhydrase?
Side effects?
1. Acetazolamide
2. M. Acidosis, NH3 toxicity, Hyper-Cl, sulfa allergy
Name a few Osmotic agents
Mannitol, glycerin and isosorbide
Mannitol contraindicated in what?
Anuria and CHF (may cause pulmonary edema)
Name an ADH analog
Vassopressin and Desmopressin
Clinical use of ADH?
Central Diabetes insipidus and Nocturnal enuresis
Name drugs that increase the release of ADH? and enhance the action of ADH?
1.Clofibrate (increase ADH release centrally)
2.Chlorpropamide, Acetominophen, indomethacin(by reducing the production of PGE and enhance the action of ADH)
Name the alpha agonist used for glaucoma?
Epinephrine (outflow, mydriasis) and Brimonidine (decrease synthesis)
what family of drugs will cause decreased aqueous humor production?
1. Bromonidine (alpha agonist)
2. Beta-blockers - Timolol, betaxolol, Carteolol
What will cause increase outflow of aqueous humor in glaucoma tx?
1. Epinephrine (as an alpha agonist)
2. Cholinomimetics: Pilocarpine, Carbachol, Physostigmine,echothiophate
3. Prostagladin - Latanoprost (darkens the color of iris)
what is used for glaucoma by increasing outflow - it darkens the iris(browning)?
Prostagladin - Latanoprost
Amantadine is used for influenza but it is also used for another condition?
Mechanism?
1. Parkinson
2. Increases the release of dopamine
Name an MAO type B inhibitor for the Tx of Parkinson?
Selegiline
Why use Benztropine in Parkinson?
What are the therapeutic effects?
1.To inhibit Ach effect.
2. Improves tremor and rigidity ( no effect on bradykinesia- slow movement)
Aside from Malignant hyperthermia - what is Dantrolene is for clinically to treat? (also dopamine agonist)
Neuroleptic malignant syndrome - rigidity, autonomic instability, hyperpyrexia

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