Autonomic Nervous System: Parasympathetic vs Sympathetic Activity

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What are the two opposing branches of the autonomic nervous system (ANS) that maintain the resting activity of organs?

Peripheral nervous system and somatic nervous system

Enteric nervous system and autonomic nervous system

Central nervous system and autonomic nervous system

Sympathetic nervous system and parasympathetic nervous system (correct)

Which neurotransmitter is associated with the parasympathetic nervous system (PNS)?

Norepinephrine

Epinephrine

Dopamine

Acetylcholine (correct)

How can changes in resting activity occur in organs according to the text?

By decreasing the activity of either the PNS or the SNS (correct)

By increasing the activity of both the PNS and the SNS

By decreasing only the activity of the sympathetic nervous system (SNS)

By increasing only the activity of the parasympathetic nervous system (PNS)

Which statement about adverse drug effects (ADRs) is accurate based on the text?

ADRs may have a therapeutic effect on target organs and an adverse effect on ancillary organs Signup and view all the answers

What is the primary focus of this chapter according to the text?

Use of drugs in primary care by advanced practice nurses to treat various conditions Signup and view all the answers

Which type of drugs target the sympathetic nervous system (SNS) by direct receptor binding or mimicking the action of norepinephrine (NE) or epinephrine?

Peripherally acting alpha-adrenergic agonists Signup and view all the answers

Which of the following is NOT a common adverse reaction in trials of methyldopa?

Insomnia Signup and view all the answers

What is the metabolic fate of approximately 50% of guanfacine's oral dose?

Converted to inactive sulfate metabolites Signup and view all the answers

In patients with renal failure, why do adverse effects of methyldopa increase?

Accumulation of methyldopa and its metabolites Signup and view all the answers

Which of the following drugs has a significant first-pass effect?

Guanfacine Signup and view all the answers

What is the primary reason for cautious use of clonidine in patients with a history of bradycardia?

Risk of mental depression Signup and view all the answers

Why should methyldopa and clonidine be used cautiously in patients with cerebrovascular disease?

They cross the blood-brain barrier Signup and view all the answers

What is the effect of stimulation of central alpha2 receptors by methyldopa's active metabolite?

Decrease in sympathetic outflow to the heart Signup and view all the answers

Which of the following receptors are primarily associated with excitation or stimulation?

Alpha1 receptors Signup and view all the answers

Where are alpha2 receptors primarily located?

Presynaptic nerve terminals of smooth muscles and islet cells of the pancreas Signup and view all the answers

What is the primary function of beta1 receptors?

Stimulation of adenylyl cyclase to increase cAMP production Signup and view all the answers

Which of the following receptors are stimulated by both norepinephrine (NE) and epinephrine?

Alpha1, alpha2, beta1, and beta2 receptors Signup and view all the answers

What is the primary use of alpha1 agonists?

Decongestants Signup and view all the answers

Which of the following is a central effect of alpha2 agonists?

Inhibition of cardioacceleration and vasoconstriction centers in the brain Signup and view all the answers

Which of the following is a potential adverse effect of centrally acting alpha2 agonists used for hypertension?

Dry mouth Signup and view all the answers

What is a potential consequence of abruptly stopping centrally acting alpha2 agonists?

Impaired homeostatic balance regulating SNS action Signup and view all the answers

Which of the following is an approved use for guanfacine?

Both A and B Signup and view all the answers

How does guanfacine reduce blood pressure?

By reducing sympathetic outflow by activating alpha2 receptors in the brain Signup and view all the answers

Which alpha1 receptor subtype is the most prevalent in the prostate?

alpha1a Signup and view all the answers

Which statement regarding the metabolism of tamsulosin is accurate?

It is extensively metabolized by CYP450 enzymes, with less than 10% eliminated unchanged. Signup and view all the answers

Which of the following statements about alfuzosin metabolism is correct?

Approximately 11% of the administered drug is eliminated unchanged in the urine. Signup and view all the answers

What is the primary reason that selective alpha1a receptor antagonists are advantageous for treating BPH?

They demonstrate fewer adverse drug reactions (ADRs) Signup and view all the answers

Which enzyme is involved in the metabolism of silodosin?

CYP3A4 Signup and view all the answers

Which of the following is NOT a characteristic of the pharmacokinetics of the alpha1 antagonist drugs?

Demonstrate low protein binding Signup and view all the answers

Which of the following alpha1 antagonist drugs has the lowest bioavailability?

Silodosin Signup and view all the answers

Based on the information provided, what is true about the active metabolite of silodosin?

It has a half-life of approximately 24 hours. Signup and view all the answers

Which alpha1 antagonist drug is known to accumulate in breast milk at a concentration 20 times that in maternal plasma?

Doxazosin Signup and view all the answers

Which of the following statements about drug interactions with alpha-blockers is accurate?

They can lead to additive hypotension, with increased risk. Signup and view all the answers

What is the primary reason that the absorption of alfuzosin is reduced when taken in a fasting state?

Alfuzosin should be administered with food Signup and view all the answers

Which statement about the metabolism and excretion of doxazosin is true?

Doxazosin exhibits biphasic plasma elimination Signup and view all the answers

What is the primary mechanism by which selective alpha1a receptor antagonists are thought to relieve lower urinary tract symptoms (LUTS) in BPH?

By a mechanism unrelated to prostate smooth-muscle relaxation Signup and view all the answers

Which alpha1 antagonist drug demonstrates the highest selectivity for the alpha1a receptor subtype?

Silodosin Signup and view all the answers

How does taking tamsulosin in a fasting state affect its pharmacokinetics?

Increases bioavailability by 30% and increases Cmax by 40-70% Signup and view all the answers

Which of the following statements about clonidine is correct?

It can cause nightmares and insomnia as an adverse reaction. Signup and view all the answers

Which drugs are well-suited for monotherapy in treating hypertension according to the text?

None of the drugs mentioned are well-suited for monotherapy Signup and view all the answers

Which of the following statements about methyldopa is true?

It is the first-line therapy for hypertension in pregnant patients. Signup and view all the answers

How can methyldopa and clonidine be used effectively for treating hypertension?

By combining them with a diuretic to address sodium and water retention Signup and view all the answers

Which of the following adverse reactions is NOT associated with centrally acting alpha2 agonists?

Hypoglycemia Signup and view all the answers

What is the recommended approach for dosing methyldopa and clonidine in treating hypertension?

Start with the lowest recommended dose and increase gradually Signup and view all the answers

How can the sedation side effect associated with clonidine and methyldopa be minimized?

By dividing the dose with a higher dose in the evening Signup and view all the answers

Which drug interaction is mentioned in the text for centrally acting alpha2 agonists?

Beta-adrenergic blockers should not be used concurrently with them. Signup and view all the answers

Which of the following statements about the use of centrally acting alpha2 agonists in children is correct?

Methyldopa can be safely used in children, but clonidine cannot. Signup and view all the answers

Which drug in this class is approved by the FDA for the treatment of ADHD in children?

Clonidine Signup and view all the answers

For which age group is clonidine considered to work better in treating hypertension?

Adults Signup and view all the answers

Which of the following adverse reactions is specifically associated with guanabenz?

Abdominal pain and vomiting Signup and view all the answers

What should be done if a patient needs to discontinue both a centrally acting alpha2 agonist and a beta-adrenergic blocker?

Discontinue the beta-adrenergic blocker first. Signup and view all the answers

Which drug formulation is available for patients who have difficulty taking pills or remembering frequent doses?

Transdermal clonidine Signup and view all the answers

Which of the following is NOT a recommended monitoring parameter for patients taking methyldopa?

Liver function tests Signup and view all the answers

What should be monitored for patients taking clonidine or methyldopa, especially those with renal impairment?

Serum creatinine levels Signup and view all the answers

Which drug was traditionally considered the drug of choice for pregnant women with hypertension?

Methyldopa Signup and view all the answers

Which of the following statements about the use of centrally acting alpha2 agonists in hypertension is correct?

They are used as second-line drugs when other drugs are not effective in achieving blood pressure control. Signup and view all the answers

What is the recommended approach for monitoring blood pressure when using clonidine or methyldopa?

Take baseline blood pressure before initiating therapy and monitor with each dosage change Signup and view all the answers

Which of the following adverse reactions is specifically associated with clonidine?

Pruritic rash Signup and view all the answers

What is the primary reason for conducting liver function studies before and during methyldopa therapy?

To monitor for potential hepatotoxicity associated with methyldopa Signup and view all the answers

How should patients take methyldopa to ensure proper dosing?

Take the missed dose as soon as possible, unless it's almost time for the next dose Signup and view all the answers

What is a potential consequence of missing doses of methyldopa?

Increased risk of experiencing rebound hypertension Signup and view all the answers

What should patients be aware of regarding potential drug-herbal interactions with methyldopa?

Methyldopa may interact with certain herbal supplements, so patients should inform their prescribers about any herbal use Signup and view all the answers

How should patients apply the transdermal clonidine patch?

Apply the patch to a hairless area of intact skin on the upper arm or torso once every 7 days, using a different site from the previous application Signup and view all the answers

What is the most common adverse reaction associated with methyldopa and clonidine?

Hypotension (low blood pressure) Signup and view all the answers

What should patients do to minimize the risk of hypotension while taking methyldopa or clonidine?

Avoid alcohol and other CNS depressants, and drink an adequate amount of non-caffeinated fluids Signup and view all the answers

What should patients report to their healthcare provider while taking methyldopa?

Any weight gain of more than 2 lb (1 kg) in 1 day, which may indicate fluid retention Signup and view all the answers

What should patients be encouraged to do in addition to taking medication for hypertension management?

Adhere to lifestyle interventions such as weight loss, exercise, low-sodium diet, smoking cessation, and stress management Signup and view all the answers

What is the primary mechanism of action of adrenergic antagonists in the treatment of hypertension?

They block adrenergic receptors or decrease norepinephrine release within sympathetic nervous system terminals Signup and view all the answers

What is the main reason nonselective alpha antagonists are not used in the treatment of hypertension?

They block presynaptic alpha2 receptors resulting in reflex cardiac stimulation Signup and view all the answers

Which statement about selective alpha1 antagonists is true?

Tamsulosin, alfuzosin, and silodosin have minimal effect on blood pressure Signup and view all the answers

What is the primary pharmacodynamic effect of reversible alpha1 antagonists?

Decrease in peripheral vascular resistance Signup and view all the answers

Why are prazosin and terazosin less likely to cause reflex tachycardia compared to other alpha1 antagonists?

They are more selective for alpha1 receptors in the vasculature Signup and view all the answers

Which drug was found to have an increased risk of heart failure (HF) in comparison to chlorthalidone according to the ALLHAT trial?