Cardiovascular I Flashcards

Question

α Adrenergic Receptors

Answer 1

GPCR Ligands - NE, epi, dopa (↑doses) α1 → excitatory ↑Ca2+ → smooth muscle contraction α2 → inhibitory ↓CAMP ↓NE release

Answer 2

β1, β2, β3 | GPCRs

Answer 3

Thiazide diuretic | UNLESS diabetes or CKD

Answer 4

Non-selective - Phentolamine - Phenoxybenzamine α1 selective ↓SVR/BP → postural HoTN common SE - Prazosin α2 selective ↑NE release → tachycardia d/t cardiac β stimulation - Yohimbine

Answer 5

Non-selective α antagonist ↓SVR → vasodilation ↓BP Reflex mediated ↑HR/CO Intraop HTN emergency - Pheo manipulation - Autonomic hyperreflexia (spinal cord injury) SQ to prevent tissue necrosis associated with sympathomimetic agents extravasation

Answer 6

HTN emergency 30-70 mcg/kg | SQ extravasation 2.5-5 mg

Answer 7

``` Non-selective α antagonist Binds covalently α1 > α2 ↓SVR → vasodilation Pro-drug Onset 1 hours Elim 1/2 time 24 hours ``` PO preop BP control in pheochromocytoma patients 0.5-1 mg/kg Start 1-2 weeks prior to OR

Answer 8

Selective α1 antagonist Tachycardia less common Dilates arterioles & and veins

Answer 9

PO preop BP control in pheochromocytoma patients Essential HTN combined w/ thiazides ↓afterload in heart failure Raynaud phenomenon - vasodilation ↑peripheral blood flow

Answer 10

Selective α2 antagonist Less common ↑NE release from the post-synaptic neuron Used to treat orthostatic HoTN & impotence

Answer 11

Terazosin & Tamsulosin Long-acting Effective prostate smooth muscle relaxation to ease micturition Most common SE → orthostatic HoTN

Answer 12

CV - bradycardia, ↓contractility/conduction velocity, & improve MVO2 supply/demand balance Blood vessels - skeletal muscle vasoconstriction ↑peripheral vascular disease Airway - bronchoconstriction & bronchospasm (asthma & COPD patients) JG cells - ↓renin release ↓volume → indirect ↓BP Pancreas - ↓insulin release at β2 & mask β1 hypoglycemia S/S

Answer 13

Receptor UPregulation | Sudden d/c → exaggerated SNS response

Answer 14

Propranolol Nadalol Timolol Pindolol

Answer 15

``` Metoprolol Atenolol Acebutolol Betaxolol Esmolol ```

Answer 16

``` ↓HR/contractility/BP PVD exacerbation d/t β2 vasodilation blocked Airway resistance → bronchospasm Altered carbohydrate & fat metabolism → masks hypoglycemia ↑HR Inhibit K+ uptake into skeletal muscles Fatigue & lethargy N/V/D ↓IOP d/t ↓aqueous humor production ↓HDLs ↑CAD risk (mechanism unknown) ```

Answer 17

Propranolol | Non-selective β antagonist

Answer 18

``` β1 selective antagonist PO 50-400mg IV 1-15mg Hepatic metabolism Elim 1/2 time 3-4 hours ```

Answer 19

Atenolol | - Least CNS effects

Answer 20

Selective β1 antagonist No hepatic metabolism Renal excretion (increased elim 1/2 time in patients w/ renal disease) PO only

Answer 21

``` Selective β1 antagonist ONLY IV Onset 60 seconds Elim 1/2 time 9 minutes Rapid plasma esterase hydrolysis Poor lipid solubility (does not cross blood-brain barrier or placenta) ```

Answer 22

Combined non-selective α AND β antagonist β >>> α ↓BP & attenuates reflex tachycardia (β2 blockade) CO unaffected Onset (max effect) 5-10 minutes after IV admin Dose 0.1-0.5 mg/kg (2.5-5 mg) Glucuronic acid conjugation & renal excretion unchanged Elim 1/2 time 5-8 hours prolonged w/ hepatic disease

Answer 23

Clonidine & Precedex MOA: ↓sympathetic outflow from vasomotor centers in the brainstem Used to treat HTN, induce sedation, ↓anesthetic requirements, improve periop hemodynamics, & analgesia PO, transdermal patch, or IV 50/50 hepatic metabolism & renal excretion

Answer 24

↓HR & peripheral vascular resistance → ↓CO & BP *Wean off to prevent rebound HTN w/ abrupt cessation Withdrawal syndrome occurs w/ doses > 1.2 mg/day Occurs 18 hours after acute dc Lasts 48-72 hours Treatment - rectal or transdermal Clonidine

Answer 25

``` Bradycardia Sedation Xerostomia (dry mouth) Impaired concentration Nightmares Depression Vertigo Extrapyramidal symptoms Male lactation ```

Answer 26

Antidiuretic hormone (ADH)

Answer 27

Produced in the hypothalamus | Stored in the posterior pituitary

Answer 28

Potent vasoconstrictor | Dilates renal afferent, pulmonary, and cerebral arterioles

Answer 29

V1 - vasoconstriction V2 - H2O reabsorption in the renal collecting ducts V3 - located in the CNS & modulate corticotrophin secretion

Answer 30

``` Post cardiopulmonary bypass shock Refractory HoTN Reduce bleeding in von Willebrand DI antidiuresis Treat enuresis (involuntary urination or wetting the bed) ```

Answer 31

1-2 units | Dilute 20 units in 20mL

Answer 32

0.03-0.04 units/min | Max dose 0.1 unit/min

Answer 33

1-5 minutes

Answer 34

10-30 minutes

Answer 35

> 0.04 units/min GI ischemia d/t potent vasoconstriction at the mesenteric artery ↓CO Skin or digital necrosis