I.  Introduction: Key Drugs
            Epinephrine
            Ephedrine
            Ergotamine
            Propranolol
            Dopamine

II. Sympathetic Nervous System

A. Sympathomimetic drugs are medications that enhance or mimic the effects of the sympathetic nervous system

B. Direct Acting Adrenergic Drugs - Catecholamines
Natural occurring catecholamines in body are:
Dopamine - a transmitter role in portions of the CNS

Norepinephrine - - important transmitter of nerve impulses

Epinephrine - emergency hormone

1. Pharmacologic Effect -Review Table 22.1, pg. 423 - Adrenergic Receptor Stimulation
a. Cardiac -
1. Inotropic Action
Increase in myocardial contraction causes complete emptying of ventricles

Increase cardiac workload

Increase O2 consumption

Increase cardiac output - epinephrine

Epinephrine produces increased fibrillation vigor and frequently promotes successful electric defibrillation

2. Chronotropic Effect - marked increase in heart rate

3. Dromotropic effect - Increase in atrioventricular conduction - eg. epinephrine can cause Ventricular Dysrhythmias

b. Vascular
1. Epinephrine - low dose - Decrease B/P
     high dose - Increase B/P
2. Norepinephrine - Increase B/P

3. Dopamine - Dose related response

c. CNS - produces alertness, tremenulousness, respiratory stimulation, and anxiety

d. Smooth muscle- Relax nonvascular smooth muscle

e. Eye - radial and spincter muscle of Iris contract - dilation of pupil (mydriasis)

f. Urinary - delay desire to void

g. Respiratory - dilate bronchial smooth muscle

h. Glandular - Dry mouth usually , Sweating

i. Metabolic - Inhibits insulin secretion - Calorigenic effect

3. Examples - Epinephrine, Isoproterenol, and Norepinephrine -

4. Drug Prototype - Epinephrine

a. Drug action - Primary Action
1. Beta1 receptors of heart - increases

2. Beta2 action dilates smooth muscle of bronchi

3. Blood vessels - activates alpha receptors to constrict arterioles of bronchioles and inhibits histamine release

b. Indication
1. Bronchial asthma

2. Acute allergic reactions

3. Adjunct with local anesthesia - decreases circulation to the area

4. Hemostatic agent

5. Management of simple, open, angle glaucoma - ocular surgery - to control bleeding

6. Cardiac Arrest -

c. Dose - Table 22-2, pg. 427
Bronchodilator - Adult - SC - 0.2 - O.5 mg every 20 minutes to 4 hours as needed.
Child - SC - 0.01 mg.kg or 0.3 mg/m2 every 15 min for 2 doses then every 4 hours as needed.
Severe Anaphylaxis - Adult - SC, IM - 0.2-0.5 mg every 10-15 min as needed
Child - SC - 0.01 mg/kg or 0.3 mg/m2, repeat every 15 min for two doses then every 4 hours as needed
Cardiac Arrest
Adult - IV, Intracardiac, Endotracheal - 0.1 mg - 1 mg, repeat as needed q 5 min.

Child - Intracardiac - 0.01 mg/kg q 5 min

Endotracheal - 0.005-0.01 mg/ kg, repeat q 5 min.
d. Nursing Care Management
1. Assessment:
a. Use with caution in CAD, CVD of any origin, Pulmonary edema, Pregnant ladies - anoxia to fetus

b. Do not use with individuals who have - narrow-angle glaucoma

d. Review current medication regimen for significant drug interaction

1. General anesthesia with cyclopane or halothane - may cause dysrhythmias

2. Digitalis - gives additive effect

2. Nursing Diagnoses
a. Side/Adverse Effects -
1. Alteration in comfort rt
CNS: nervousness, restlessness, insomnia, tremor, headache

GI: nausea, vomiting

2. Alteration in cardiac output rt
CV: hypertension, dysrhythmias, angina
3. PC Hyperglycemia
Endo: hyperglycemia
4. Risk for injury:

5. Alteration in elimination: GU: urinary retention, hesitancy

3. Implementation
a. Monitoring
1. Check vital signs and EKG for evidence of cardiac problems

2. Observe for loss of diabetic control

b. Interventions
1. Use with caution in elderly

2. Avoid overdosage may cause extreme HTN/CV Bleed (Stroke)

3. Store medication properly - should be clear in color - discard if pink or brown.

4. Parenteral Administration

Check strength of solution you are using 1: 100 versus 1:1000

Always aspirate SC/IM

Dilute 1:1000 before IV or Intracardiac administration

May give endotracheally

           5. Inhalation - give q4h

            6. Nasal Administration - administer with head low in
                lateral position

4. Education
a. Caution against tolerance - "Epinephrine Fastness"

b. Emergency auto-injection - Deltoid/thigh

c. Inhalation - use metered dose properly - allow 2 minutes between doses. Do not overuse. Call doctor if not responding to usual dose, experience angina or pulse rate increases more than 20-30 beats/minute.

d. Nasal Administration

Do not use more than 3-5 days

May produce sensation of stinging

Rebound congestion may occur

e. Ophthalmic - use proper instillation technique to avoid systemic effects
  5. Evaluation
a. Client's symptoms are relieved.

b. Vital signs are within normal range

5. Drug prototype - Dopamine
a. Indications
1. Heart failure

2. Post cardiac surgery

3. Low cardiac output syndromes

b. Drug action - dose related
1. Low dose - 0.5 - 2 mcg/kg/min - Causes vasodilation of renal/mesenteric arteries

2. Moderate dose - 2 - 10 mcg/kg/min - Causes increased myocardial contractility and stroke volume causes increased cardiac output.

3. High dose - >10 mcg/kg/min - Causes B/P increase and decreased urinary output

c. Nursing Diagnoses - side effect
1. Alteration in comfort rt HA, N/V rt

2. Decreased cardiac output rt

3. PC: Dysrhythmias

d.  Expected Outcomes
            1.  VS WNL
            2.   Improved CVP and PAWP
            3.   Urine output increased to >30cc/hr
            4.   Absence of adventitious breath sounds
C. Indirect and Dual Acting Adrenergic Drugs
1. Ephedrine - increases blood pressure - used in spinal surgery and to treat orthostatic hypotension

2. Neosynephrine - causes vasoconstriction - used in spinal surgery and in many combination cough/cold products

D. Adrenergic Blocking Agents - See chart in syllabus
1. Categories:
a. Non competitive, long acting antagonists - phenoxybenzamine (Dibenzyline)

b. Competitive, short acting antagonists - phentolamine (Regitine)

c. Ergot alkaloids - Ergotamine tartrate (Ergomar) See Table 22-6, pg. 445 for dosage)

2. Construct a chart to compare/contrast agents considering drug action, indication, dose, side/ adverse effect, and nursing care management
E. Beta Adrenergic Blocking Agents
1. Classification
a. Selective beta1 - atenolol, metoprolol (cardioselective)

b. Nonselective beta adrenergic - propranolol
 

2. Drug Action: Blocks stimulation of beta1 (myocardial) and beta2 (pulmonary, vascular, and uterine) receptor sites

3. Indications:

Angina Pectoris, Hypertension (HTN), Cardiac Dysrhythmias, Hypertrophic Cardiomyopathies, Migraine prophylaxis

Adjunct - Thyroid/pheochromocytoma

Stage fright

Prevent Second Myocardial Infarction

4. Usual Dose - See Table 22-7, pg. 448.

5. Nursing Management

a. Assessment
1. Oxygenation - Bronchospasm, dyspnea, rales/crackles, fatigue, weight gain, jugular venous distention

2. Endocrine - Diabetes and hypoglycemia - mask. Thyrotoxicosis - may mask signs of hyperthyroidism

3. Mental Depression - exacerbates

b. Nursing Diagnoses - side effects
1. Side/Adverse Effects
CNS: fatigue, weakness, depression, insomnia, memory loss, mental changes, drowsiness confusion, dizziness

EENT: dry eyes, blurred vision, nasal stuffiness

Resp: Bronchospasm, wheezing,

CV: BRADYCARDIA, CONGESTIVE HEART FAILURE, PULMONARY EDEMA, hypotension

GI: constipation, diarrhea, nausea, vomiting

GU: impotence, diminished libido

Derm: rash

Endo: hyperglycemia, hypoglycemia

2. Nursing Diagnoses/Potential Complications
Alteration in thought processes

Ineffective airway clearance

Sexual dysfunction

Alteration in skin integrity

PC: hyperglycemia
PC: hypoglycemia

Misc: Raynaud's phenomena

c. Implementation
1. Monitoring
a. Check Vital signs and EKG
b. Check for edema - fluid retention
c. Check blood sugar levels
2. Interventions
a. Drug must be withdrawn slowly
 
b. Be consistent - take with or without food

c. Lab Test Considerations - Hepatic and Renal Tests if receiving prolonged therapy.

d. Education
1. Check pulse/ Blood Pressure

2. Do not stop drug abruptly - rebound HTN crisis may occur

3. Continue additional therapies

4. May cause drowsiness

5. May cause increase sensitivity to cold

6. Check about OTC with doctor

7. Inform doctor/dentist of regimen

8. Diabetics monitor glucose carefully

9. Instruct to wear Med-Alert band

e. Evaluation
1. Rx hypertension - Decrease in B/P

2. Rx angina pectoris - Decrease in frequency of anginal attacks

3. Rx dysrhythmias - Decrease or no dysrhythmias

4. Rx migraines - Decrease or no migraines

5. Rx tremors - Decrease in tremors
 

Source: McKenry and Salerno, 1998, Chp 22
 
                                                                                                         Designed
Carol Zeller
Revised 7/01