Drug List Flashcards
Norepinephrine
sympathetic agonist: a1 = a2, b1>>b2: “pressor agent”
Effects on Heart:
- direct: positive inotropic and chronotropic via B1
- indirect: results in reflex bradycardia (blocked by atropine)
- net effect: slow, forceful HR
Effects on Blood Vessels:
- a1 mediated vasoconstriction, increased BP
Epinephrine: what is its effect on the heart? what is its effect on the blood vessels? What is its effect on smooth muscle?
- a1 = a2, b1 = b2
- sympathomimetic agonist
Has Major effects on HEART:
- chronotropic effect
- inotropic effect
- increased conduction in atria, A-V nodes and purkinge fibers
- the work of the heart is increased substantially and thus oxygen consumption is greatly increased (bad for people with MI’s)
At Blood Vessels of Skeletal Muscle: stimulates both a1-vasoconstriction and B2-vasodilation. Epi is more potent at B2 than a1, thus at low concentrations and vasodilation will predominate. However, at high concentrations (what is used in hospitals) a1 vasoconstriction predominates. Epi >>> NE at B2. Thus blood pressure will increase.
Smooth Muscle: results in Bronchial smooth muscle relaxation via B2 and opens the bronchial airways
Isoproterenol
- potent against all b receptors: no a effects
- sympathomimetic (agonists): synthetic catecholamine
Heart:
- results in B1 increased HR and force
Blood Vessels:
- B2 vasodilation in skeletal muscle and mesentary
- decreased diastolic BP, increased systolic BP - results in slight decrease to mean BP
phenylephrine (Neo-Synephrine)
a1 > a2 >>>>> b
a1-Selective Agonist: pressor agent
- results in vasoconstriction, increased peripheral resistance, increased BP resulting in reflex bradycardia (blocked by atropine)
Albuterol (Proventil, Ventolin)
B2>>B1>>>>>a
B2- selective agonist: effect on lung > heart (x10)
results in bronchodilation, and is used to treat bronchospasm in asthma
-side effects could result in muscle tremors and tachycardia due to B1 activation and reflex.
Dobutamine (Dobutrex)
B1-Selective Agonist
Clinically: mostly B1 effects: resulting in positive inotropic and some increase in HR. CO increases, little vascular effect
Clincal Uses: MI, CHF, Cardiogenic shock
(b1 > b2 >>a1)
Dopamine (Intropin): what is it used clinically for?
Dopamine Agonist
Used clinically for Cardiogenic Shock: heart able to pump as much blood as the body needs
Pharmacological effects:
- blood vessels (D1 receptors): vasodilates renal –> increased blood flow to kidney
- heart (B1 agonist): mild increase in rate and force of contraction
- blood vessels (a1 receptors): **high does causes vasoconstriction and increased BP **
(D1=D2>>b>>a)
Propranolol: pharmacological effects? contraindications?
- Nonselective B-Adrenergic Antagonist
- b1=b2>>>a
- Pharmacological effect on the heart:
- decreases heart rate and CO, decreases exercise tolerance
- decreases work of heart and O2 demand
- decreases AV nodal conduction and reduces infarct size to prevent sudden death
- Contraindications?
- Blocks sympathomimetic bronchodilation: do not use to treat people with asthma and COPD
- Blocks B receptor lipolysis and glycogenolysis. May mask signs of hypoglycemia and may potentiate in insulin-induced hypoglycemia in diabetics
Atenolol
b1-Selective B-adrenergic Antagonist
- used to treat cardio problems
- lessen risk of bronchospasm; but still contraindicated in asthmatic
- do not usually prolong hypoglycemia
(b1>>b2)
Metropolol
B1-Selective B-adrenergic Antagonist: but also blocks B2 at higher doses
- lessened risk of bronchospasm as opposed to B2 antagonists: still contraindicated in asthmatic patients
- does not usually prolong hypoglycemia: OK to use with diabetics
Phentolamine
- Nonselective a-Adrenergic Antagonist
- a1 = a2: alpha receptor blocker
Prazosin (Minipress): what is it used to treat?
a-1 selective a-Adrenergic Antagonist
- a1>>>>>a2
- used to treat hypertension, benign prostatic hypertrophy
Carvedilol
- mixed antagonist: nonselectively blocks B and a receptors : b1 = b2 ≥ a1 >a2
- very dramatic results in CHF clinical trials
What are three muscarinic cholinergic Agonists?
Acetylcholine (Muscarinic and Nicotinic Agonist)
Bethanechol (M1-5 >>>>NM,NN)
Methacholine
- decrease HR velocity and contraction strength,
- result in bronchial smooth muscle contraction
- increased tone and contraction of extravascular smooth muscles
What are 3 muscarinic Receptor Antagonists? what are their pharmacological uses?
Atropine (Oral, Parenteral, Ophthalmic)
- (M1 = M2 = M3 >>>>>NM,NN)
- blocks ALL muscarinic receptors
- blocks PS slowing of the heart and promotes tachycardia
Ipratropium
- inhalation drug to reverse bronchial constriction and secretion
- used to treat emphysema, chornic bronchitis and sometimes asthma
- often combined with albuteterol to make combivent
Tiotropium (Inhalation only)
- similar effects to ipratropium, but longer lasting