Updated: 1/19/2019

Sympathomimetics

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Questions
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sympmathomimetics 
 
Direct Sympathomimetics
 
Drug Receptor Selectivity Clinical Applications
Epinephrine

β  > α

• Anaphylaxis
• Cardiac arrest
• Glaucoma (open angle)
• Asthma and broncho spasms
• Hypotension

Norepinephrine 

 

α1 > α2 > β1

• Shock
• Severe hypotension (but ↓ renal perfusion)
• Causes reflex bradycardia
Midodrine Selective α1 agonist • Orthostatic hypotension
Phenylephrine α1 > α • Pupillary dilation and glaucoma (wide angle)
• Vaso constriction
• Nasal decongestion
Clonidine, α-methyldopa Centrally acting α2-agonists, ↓ central adrenergic outflow • Hypertension
• Does not ↓ blood flow to the kidney
Isoproterenol β1= β2 • Heart block
Dopamine

low dose (vasodilation, naturiesis): D1 = D2
medium dose (tachycardia): β1
high dose (vaso- constriction): α1 , inotropic and chronotropic

• Shock and ↑ renal perfusion
• Heart failure
Fenoldopam Selective D1 agonist • Hypertension
Bromocriptine Selective D2 agonist • Parkinson's disease
• Prolactinemia
Dobutamine β1> β2, positive inotropic effect    • Cardiogenic shock
• Acute heart failure
• Cardiac stress testing
Metaproterenol, albuterol, salmeterol  Selective β2 agonists • Albuterol and metaproterenol for acute asthma
• Salmeterol for long-term treatment

Ritodrine

Terbutaline

Selective β2 agonists • Reduction of premature uterine contractions

 

 

Indirect Sympathomimetics
 
Drug
Mechanism
Clinical Applications
Amphetamine Releases stored catecholamines
  • Narcolepsy
  • Obesity
  • Attention deficit disorder
Ephedrine Releases stored catecholamines
  • Nasal decongestion
  • Urinary incontinence
  • Hypotension
Cocaine Reuptake inhibitor
  • Causes vasoconstriction and local anesthesia
 

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Questions (12)
Lab Values
Blood, Plasma, Serum Reference Range
ALT 8-20 U/L
Amylase, serum 25-125 U/L
AST 8-20 U/L
Bilirubin, serum (adult) Total // Direct 0.1-1.0 mg/dL // 0.0-0.3 mg/dL
Calcium, serum (Ca2+) 8.4-10.2 mg/dL
Cholesterol, serum Rec: < 200 mg/dL
Cortisol, serum 0800 h: 5-23 μg/dL //1600 h:
3-15 μg/dL
2000 h: ≤ 50% of 0800 h
Creatine kinase, serum Male: 25-90 U/L
Female: 10-70 U/L
Creatinine, serum 0.6-1.2 mg/dL
Electrolytes, serum  
Sodium (Na+) 136-145 mEq/L
Chloride (Cl-) 95-105 mEq/L
Potassium (K+) 3.5-5.0 mEq/L
Bicarbonate (HCO3-) 22-28 mEq/L
Magnesium (Mg2+) 1.5-2.0 mEq/L
Estriol, total, serum (in pregnancy)  
24-28 wks // 32-36 wks 30-170 ng/mL // 60-280 ng/mL
28-32 wk // 36-40 wks 40-220 ng/mL // 80-350 ng/mL
Ferritin, serum Male: 15-200 ng/mL
Female: 12-150 ng/mL
Follicle-stimulating hormone, serum/plasma Male: 4-25 mIU/mL
Female: premenopause: 4-30 mIU/mL
midcycle peak: 10-90 mIU/mL
postmenopause: 40-250
pH 7.35-7.45
PCO2 33-45 mmHg
PO2 75-105 mmHg
Glucose, serum Fasting: 70-110 mg/dL
2-h postprandial:<120 mg/dL
Growth hormone - arginine stimulation Fasting: <5 ng/mL
Provocative stimuli: > 7ng/mL
Immunoglobulins, serum  
IgA 76-390 mg/dL
IgE 0-380 IU/mL
IgG 650-1500 mg/dL
IgM 40-345 mg/dL
Iron 50-170 μg/dL
Lactate dehydrogenase, serum 45-90 U/L
Luteinizing hormone, serum/plasma Male: 6-23 mIU/mL
Female: follicular phase: 5-30 mIU/mL
midcycle: 75-150 mIU/mL
postmenopause 30-200 mIU/mL
Osmolality, serum 275-295 mOsmol/kd H2O
Parathyroid hormone, serume, N-terminal 230-630 pg/mL
Phosphatase (alkaline), serum (p-NPP at 30° C) 20-70 U/L
Phosphorus (inorganic), serum 3.0-4.5 mg/dL
Prolactin, serum (hPRL) < 20 ng/mL
Proteins, serum  
Total (recumbent) 6.0-7.8 g/dL
Albumin 3.5-5.5 g/dL
Globulin 2.3-3.5 g/dL
Thyroid-stimulating hormone, serum or plasma .5-5.0 μU/mL
Thyroidal iodine (123I) uptake 8%-30% of administered dose/24h
Thyroxine (T4), serum 5-12 μg/dL
Triglycerides, serum 35-160 mg/dL
Triiodothyronine (T3), serum (RIA) 115-190 ng/dL
Triiodothyronine (T3) resin uptake 25%-35%
Urea nitrogen, serum 7-18 mg/dL
Uric acid, serum 3.0-8.2 mg/dL
Hematologic Reference Range
Bleeding time 2-7 minutes
Erythrocyte count Male: 4.3-5.9 million/mm3
Female: 3.5-5.5 million mm3
Erythrocyte sedimentation rate (Westergren) Male: 0-15 mm/h
Female: 0-20 mm/h
Hematocrit Male: 41%-53%
Female: 36%-46%
Hemoglobin A1c ≤ 6 %
Hemoglobin, blood Male: 13.5-17.5 g/dL
Female: 12.0-16.0 g/dL
Hemoglobin, plasma 1-4 mg/dL
Leukocyte count and differential  
Leukocyte count 4,500-11,000/mm3
Segmented neutrophils 54%-62%
Bands 3%-5%
Eosinophils 1%-3%
Basophils 0%-0.75%
Lymphocytes 25%-33%
Monocytes 3%-7%
Mean corpuscular hemoglobin 25.4-34.6 pg/cell
Mean corpuscular hemoglobin concentration 31%-36% Hb/cell
Mean corpuscular volume 80-100 μm3
Partial thromboplastin time (activated) 25-40 seconds
Platelet count 150,000-400,000/mm3
Prothrombin time 11-15 seconds
Reticulocyte count 0.5%-1.5% of red cells
Thrombin time < 2 seconds deviation from control
Volume  
Plasma Male: 25-43 mL/kg
Female: 28-45 mL/kg
Red cell Male: 20-36 mL/kg
Female: 19-31 mL/kg
Cerebrospinal Fluid Reference Range
Cell count 0-5/mm3
Chloride 118-132 mEq/L
Gamma globulin 3%-12% total proteins
Glucose 40-70 mg/dL
Pressure 70-180 mm H2O
Proteins, total < 40 mg/dL
Sweat Reference Range
Chloride 0-35 mmol/L
Urine  
Calcium 100-300 mg/24 h
Chloride Varies with intake
Creatinine clearance Male: 97-137 mL/min
Female: 88-128 mL/min
Estriol, total (in pregnancy)  
30 wks 6-18 mg/24 h
35 wks 9-28 mg/24 h
40 wks 13-42 mg/24 h
17-Hydroxycorticosteroids Male: 3.0-10.0 mg/24 h
Female: 2.0-8.0 mg/24 h
17-Ketosteroids, total Male: 8-20 mg/24 h
Female: 6-15 mg/24 h
Osmolality 50-1400 mOsmol/kg H2O
Oxalate 8-40 μg/mL
Potassium Varies with diet
Proteins, total < 150 mg/24 h
Sodium Varies with diet
Uric acid Varies with diet
Body Mass Index (BMI) Adult: 19-25 kg/m2
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(M1.PH.6000) In an attempt to create other selective dopamine 1 (D1) agonists, a small pharmaceutical company created a cell-based chemical screen that involved three modified receptors - alpha 1 (A1), beta 1 (B1), and D1. In the presence of D1 stimulation, the cell would produce an mRNA that codes for a fluorescent protein; however, if the A1 or B1 receptors are also stimulated at the same time, the cells would degrade the mRNA of the fluorescent protein thereby preventing it from being produced. Which of the following would best serve as a positive control for this experiment? Review Topic

QID: 106941
1

Bromocriptine

22%

(34/158)

2

Dobutamine

9%

(15/158)

3

Dopamine

23%

(37/158)

4

Epinephrine

13%

(21/158)

5

Fenoldopam

30%

(47/158)

M1

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PREFERRED RESPONSE 5

(M1.PH.1) A high-throughput screen to identify new sympathomimetic compounds was developed such that a transgenic line of cells was created that contained the alpha-1 (red), alpha-2 (yellow), beta-1 (green) and beta-2 (blue) receptors. When each of the receptors was activated a different fluorescent protein was expressed and new compounds with different properties could be identified by the fluorescence that they induced. Compound 7583 selectively induced the expression of the blue fluorescent protein. Which of the following known sympathomimetic medications if administered would similarly result in expression of only the blue fluorescent protein? Review Topic

QID: 107079
1

Albuterol

68%

(103/151)

2

Midrodrine

6%

(9/151)

3

Epinephrine

9%

(14/151)

4

Isoproterenol

11%

(16/151)

5

Fenoldopam

3%

(5/151)

M1

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PREFERRED RESPONSE 1

(M1.PH.46) A 58-year-old male is diagnosed with hypertension and started on daily propranolol after failing antihypertensive therapy with other medications. Three months later, his blood pressure appears to be adequately controlled on this therapy. While working in his garden one afternoon, the patient is stung by a wasp and experiences a severe anaphylactic reaction that is subsequently treated with epinephrine. Which of the following effects would be expected upon administration of this epinephrine treatment? Review Topic

QID: 100562
1

Decreased bronchodilation

11%

(22/203)

2

Increased motility of the gastrointestinal tract

3%

(6/203)

3

Decreased heart rate

23%

(46/203)

4

Decreased blood pressure

5%

(11/203)

5

Increased heart rate

55%

(112/203)

M1

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PREFERRED RESPONSE 3

(M1.PH.107) An 82-year-old male with congestive heart failure experiences rapid decompensation of his condition, manifesting as worsening dyspnea, edema, and increased fatigue. Labs reveal an increase in his serum creatinine from baseline. As part of the management of this acute change, the patient is given IV dobutamine to alleviate his symptoms. Which of the following effects occur as a result of this therapy? Review Topic

QID: 100623
1

Slowed atrioventricular conduction velocities

6%

(13/201)

2

Increased myocardial oxygen consumption

56%

(113/201)

3

Decreased heart rate

11%

(22/201)

4

Increased systemic vascular resistance due to systemic vasoconstriction

21%

(42/201)

5

Decreased cardiac contractility

4%

(8/201)

M1

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PREFERRED RESPONSE 2
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(M1.PH.75) A 75-year-old male arrives by ambulance to the emergency room severely confused. His vitals are T 40 C, HR 120 bpm, BP 80/55 mmHg, RR 25. His wife explains that he injured himself about a week ago while cooking, and several days later his finger became infected, oozing with pus. He ignored her warning to see a doctor and even refused after he developed fever, chills, and severe fatigue yesterday. After being seen by the emergency physician, he was given antibiotics and IV fluids. Following initial resuscitation with IV fluids, he remains hypotensive. The ED physicians place a central venous catheter and begin infusing norepinephrine. Which of the following receptors are activated by norepinephrine? Review Topic

QID: 106852
1

Alpha 1

3%

(1/34)

2

Alpha 2

3%

(1/34)

3

Alpha 1, Alpha 2, Beta 1

50%

(17/34)

4

Alpha 1, Alpha 2, Beta 1, Beta 2

26%

(9/34)

5

Alpha 1, Beta 1, Dopamine 1

12%

(4/34)

M1

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PREFERRED RESPONSE 3

(M1.PH.86) A 24-year-old male being treated for syphilis is given penicillin. Shortly after receiving the first dose the patient becomes dyspneic. Immediate assessment of the patient reveals a heart rate of 150 bpm and a blood pressure of 88/50. The first-line drug used in the treatment of this condition has what effect on alpha and beta autonomic receptors? Review Topic

QID: 100602
1

Alpha-1 agonism, beta-1 agonism

43%

(104/244)

2

Alpha-1 agonism, beta-1 antagonism

20%

(50/244)

3

Alpha-1 antagonism, beta-1 agonism

22%

(53/244)

4

Alpha-1 antagonism, beta-1 antagonism

6%

(15/244)

5

Alpha-1 agonism, no effect on beta-1

6%

(14/244)

M1

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PREFERRED RESPONSE 1

(M1.PH.77) A 35-year-old male presents to his primary care physician with complaints of seasonal allergies. He has been using intranasal vasoconstrictors several times per day for several weeks. What is a likely sequela of the chronic use of topical nasal decongestants? Review Topic

QID: 100593
1

Epistaxis

19%

(33/178)

2

Hypertension

10%

(17/178)

3

Permanent loss of smell

7%

(12/178)

4

Persistent nasal crusting

33%

(59/178)

5

Persistent congestion

26%

(47/178)

M1

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PREFERRED RESPONSE 5
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