Characteristics of Adrenergic Drugs (p. 291) Mimic the effects of SNS neurotransmitters (catecholamines) Norepinephrine (NE) Epinephrine (EPI) Dopamine Also known as andrenergic agonists, sympathomimetics NURSING APPLICATION: Ms. Jackson begins to have difficulty breathing. She becomes short of breath and the doctor has ordered albuterol. Why? Copyright line.

Copyright © 2011 by Elsevier Inc. All rights reserved. Catecholamines (p. 289) Substances that can produce a sympathomimetic response Endogenous Epinephrine, norepinephrine, dopamine Synthetic Dobutamine, phenylephrine Can be direct-acting, indirect-acting, or mixed-acting sympathomimetic NURSING APPLICATION: Ms. Jackson continues to have difficulty breathing, and the physician suspects she is having a reaction to the new antibiotic that was started about 45 minutes ago. Why would he order epinephrine? Copyright © 2011 by Elsevier Inc. All rights reserved.

Copyright © 2011 by Elsevier Inc. All rights reserved. Drug Effects (p. 291) Stimulation of alpha-adrenergic receptors on smooth muscles results in: Vasoconstriction of blood vessels Relaxation of GI smooth muscles (decreased motility) Constriction of bladder sphincter Contraction of uterus Male ejaculation Contraction of pupillary muscles of the eye (dilated pupils) Indications (p. 292) Treatment of asthma and bronchitis Bronchodilators: drugs that stimulate beta2-adrenergic receptors of bronchial smooth muscles, causing relaxation, resulting in bronchodilation Examples: albuterol, ephedrine, epinephrine, formoterol, levalbuterol, metaproterenol, pirbuterol, salmeterol, and terbutaline (used to stop premature labor; causes relaxation of uterine smooth muscle) NURSING APPLICATION: Ms. Jackson’s breathing soon becomes more regular, but her blood pressure has become elevated. Why could this happen? Copyright © 2011 by Elsevier Inc. All rights reserved.

Vasoactive Adrenergics (Pressors, Inotropes) (p. 293) Also called cardioselective sympathomimetics Used to support the heart during cardiac failure or shock; various alpha and beta receptors affected Administering two adrenergic drugs together may precipitate severe cardiovascular effects such as tachycardia or hypertension Potent, quick-acting, injectable drugs. Nursing Implications (cont’d) (p. 298) Salmeterol is indicated for prevention of bronchospasms, not management of acute symptoms. Overuse of nasal decongestants may cause rebound nasal congestion or ulcerations. Avoid over-the-counter or other medications because of possible interactions. NURSING APPLICATION: Ms. Jackson’s blood pressure begins to drop drastically, and the physician has ordered dopamine IV. Why? Copyright © 2011 by Elsevier Inc. All rights reserved.

Adrenergic Blockers (cont’d) (p. 301) Classified by the type of adrenergic receptor they block Alpha1 and alpha2 receptors Beta1 and beta2 receptors Alpha-blockers work either by direct competition with norepinephrine or by a noncompetitive process. NURSING APPLICATION: Ms. Jackson’s 65-year-old son was in the room when his mother had the problem with her respirations and breathing. He says that he has high blood pressure but has forgotten to take his blood pressure medicine. Why would an adrenergic blocking drug be effective to lower his blood pressure? Copyright line.

Drug Effects and Indications: Alpha-Blockers (p. 303) Cause both arterial and venous dilation, reducing peripheral vascular resistance and BP Used to treat hypertension Effect on receptors on prostate gland and bladder decreases resistance to urinary outflow, thus reducing urinary obstruction and relieving effects of BPH Also used to control and prevent hypertension in patients with pheochromocytoma NURSING APPLICATION: How do alpha-blockers assist to lower blood pressure? Copyright © 2011 by Elsevier Inc. All rights reserved.

Copyright © 2011 by Elsevier Inc. All rights reserved. Beta-Blockers (p. 304) Block stimulation of beta receptors in the SNS Compete with norepinephrine and epinephrine Can be selective or nonselective Nonselective beta-blockers block both beta1 and beta2 receptors The blocking of beta 2 receptors in the bronchioles may cause shortness of breath. NURSING APPLICATION: How could a beta blocker cause dizziness? Copyright © 2011 by Elsevier Inc. All rights reserved.

Adrenergic-Blocking Drugs: Nursing Implications (p. xxx ) Assess for allergies and history of: COPD Hypotension Cardiac dysrhythmias Bradycardia Heart failure Other cardiovascular problems Remember that alpha-blockers may precipitate hypotension. NURSING APPLICATION: Why would these condition be problematic? Copyright © 2011 by Elsevier Inc. All rights reserved.

Adrenergic-Blocking Drugs: Nursing Implications (cont’d) (p. 305) Avoid over-the-counter medications because of possible interactions Possible drug interactions may occur with: Antacids (aluminum hydroxide type) Antimuscarinics/anticholinergics Diuretics and cardiovascular drugs Neuromuscular blocking drugs Oral hypoglycemic drugs Remember that some beta-blockers may precipitate bradycardia, hypotension, heart block, heart failure, and bronchoconstriction. NURSING APPLICATION: Explain to Ms. Jackson's son why he should avoid specific over-the-counter medications. Copyright line.

Beta-Blocking Drugs: Nursing Implications (p. 307) Rebound hypertension or chest pain may occur if this medication is discontinued abruptly Instruct patients to notify their physician if they become ill and unable to take medication Inform patients that they may notice a decrease in tolerance for exercise (dizziness and fainting may occur with increased activity), and have patients notify the physician if these problems occur Patients should report weight gain, edema, shortness of breath, fatigue, or dizziness. NURSING APPLICATION: Explain to Ms. Jackson's son why he may be experiencing chest pain as a result of skipping his blood pressure medication today. Copyright © 2011 by Elsevier Inc. All rights reserved.