Ch 12-14, 18 Neurologic Med

Which condition would alert the nurse of the need to use beta-adrenergic blockers cautiously?

• Hypertension

• Raynaud’s phenomenon

• Emphysema

• Cardiac dysrhythmias

Answer explanation

Beta-adrenergic blockers can produce severe bronchoconstriction. Selective beta 1 antagonists are used to treat hypertension. Alpha-adrenergic blocking agents are used to treat patients with Raynaud‘s disease. Beta-adrenergic blocking agents are indicated for patients with cardiac arrhythmias.

Which explanation by the nurse is most accurate when a patient with chronic obstructive pulmonary disease (COPD) reports having insomnia and a racing heart after starting terbutaline therapy?

• The symptoms are typical and indicate that the medication is at a therapeutic level

• The symptoms will tend to resolve with continued therapy

• The symptoms are unusual and need to be reported to the healthcare provider immediately

• The symptoms are indicative of toxicity

Answer explanation

Terbutaline, an adrenergic agent effective for bronchodilation, can cause excessive central nervous system (CNS) stimulation. Adverse effects such as palpitations, tachycardia, flushed skin, dizziness, and tremors tend to be mild and resolve with continued therapy. The therapeutic level can only be determined by analyzing a blood sample. These are common symptoms and should only be reported if they persist. Symptoms of toxicity are chest pain, persistent palpitations, and tachycardia.

Which response is the primary response to alpha-1–receptor stimulation?

• Bronchodilation

• Tachycardia

• Vasoconstriction

• Uterine relaxation

Answer explanation

Stimulation of the alpha-1 receptors causes vasoconstriction of all blood vessels throughout the body. Alpha-1–receptor stimulation causes bronchoconstriction. Alpha-1–receptor stimulation does not cause tachycardia. Beta-2–receptor stimulation produces relaxation of smooth muscle tissue, such as the uterus.

Which category of medications is used for peripheral vascular diseases characterized by excessive vasoconstriction, such as Raynaud‘s disease?

• Adrenergic agents

• Alpha-adrenergic blocking agents

• Beta-adrenergic blocking agents

• Cholinergic agents

Answer explanation

Alpha-adrenergic blocking agents interfere with the stimulation of alpha-1 and alpha-2 receptors. Because the primary action of alpha-receptor stimulation is vasoconstriction, alpha-adrenergic blocking agents are indicated for patients with diseases associated with vasoconstriction. Adrenergic drugs cause vasoconstriction. Beta-adrenergic blocking agents are used to treat hypertension and dysrhythmias. Cholinergic drugs are used to treat ocular diseases such as glaucoma, respiratory tract disease, and urinary system diseases.

Which explanation provides rationale for why beta blockers are used cautiously in patients with respiratory conditions?

• Mask the signs and symptoms of acute hypoglycemia.

• Cause extensive vasodilation and cardiac overload.

• May produce severe bronchoconstriction.

• Increase hypertensive episodes.

Answer explanation

Nonselective beta blockers, such as Inderal, and larger doses of selective beta antagonists will readily affect the beta-2 receptors of the bronchi, causing bronchoconstriction. Therefore, beta blockers must be used with extreme caution in patients with respiratory conditions such as bronchitis, emphysema, asthma, or allergic rhinitis. Beta blockers affect blood glucose by inducing the hypoglycemic effects of insulin. Vasodilation relieves cardiac overload. Beta blockers induce hypotensive effects.

Which response by the nurse is most accurate when a patient with the diagnosis of Parkinson's disease asks the nurse why anticholinergics are used in the treatment?

• These drugs help you urinate.

• These drugs will decrease your eye pressure.

• These drugs inhibit the action of acetylcholine.

• These drugs will assist in lowering your heart rate.

Answer explanation

Anticholinergic agents inhibit the action of acetylcholine in the parasympathetic nervous system. These drugs occupy receptor sites at the parasympathetic nerve endings, preventing the action of acetylcholine. Inhibition of acetylcholine facilitates stimulation of the dopaminergic receptors, which relieves the symptoms associated with Parkinson‘s disease. Anticholinergic agents cause urinary retention, increase intraocular pressure, and increase the heart rate.

Which condition is important to screen a patient for before the initiation of anticholinergic medications?

• Hypertension

• Infectious diseases

• Diabetes

• Closed-angle glaucoma

Answer explanation

The inhibition of cholinergic activity (anticholinergic effects) causes pupil dilation, which increases intraocular pressure in patients with glaucoma. In patients with closed-angle glaucoma, anticholinergic medications can precipitate an acute attack. Anticholinergic agents may produce increased heart rate but not hypertension. Anticholinergic agents do not affect infections or diabetes.

Which nerve endings liberate norepinephrine?

• Cholinergic

• Adrenergic

• Anticholinergic

• Muscarinic

Answer explanation

Nerve endings that secrete norepinephrine are called adrenergic fibers. These nerve endings liberate acetylcholine. Anticholinergic describes the action of certain medications that inhibit the transmission of parasympathetic nerve impulses and thereby reduce spasms of smooth muscle (e.g., as in the bladder). Muscarinic receptors are those membrane bound acetylcholine receptors that are more sensitive to muscarine than to nicotine.

Which types of adrenergic receptors subdivide the autonomic nervous system?

• Nicotinic and muscarinic

• Afferent and efferent

• Alpha and beta

• Agonists and antagonists

Answer explanation

The autonomic nervous system can be subdivided into alpha- and beta-adrenergic receptors. Nicotine and muscarine are specific agonists of one type of cholinergic receptor. Afferent and efferent are sensory and motor nerves. An agonist is a molecule that activates a receptor by reproducing the effect of the neurotransmitter. An antagonist acts against and blocks a function.

Which is most important for the nurse to assess prior to the administration of metoprolol, a beta-adrenergic blocking agent?

• Blood pressure

• Lung sounds

• Mental status

• Urine output

Answer explanation

Beta-adrenergic blocking agents cause vasodilation and decreased heart rate, resulting in lowering of the blood pressure. A premedication assessment is to take baseline heart rate and blood pressure. Fluid retention may occur as a serious adverse effect but is not the most important assessment prior to the administration of a beta-adrenergic blocking agent. Mental status and urine output are not the most important assessments prior to the administration of a beta-adrenergic blocking agent.