MSN-611-Advanced Pharmacology Across The Life Span

Correct Answer: D. Many antiepileptics can reduce the efficacy of oral contraceptives

Explanation:

Antiepileptic drugs (AEDs), also known as antiepileptics, are commonly prescribed to manage seizure disorders. One key concern when prescribing these medications is that many antiepileptic drugs can interact with oral contraceptives, reducing their efficacy. This interaction is particularly relevant for women who use oral contraceptives for birth control, as certain AEDs can increase the metabolism of contraceptive hormones, leading to a decreased effectiveness and potentially increasing the risk of unintended pregnancies. Carbamazepine, phenytoin, and topiramate are examples of antiepileptic drugs known to affect oral contraceptive efficacy. This is an important consideration for the APRN when prescribing these drugs, and alternative methods of contraception or higher-dose contraceptives may need to be considered.

Why the Other Options Are Incorrect:

A. These medications can all lead to addiction

While some antiepileptics, like benzodiazepines, do have the potential for dependence or addiction, this is not a general concern for all antiepileptics. Antiepileptic drugs such as phenytoin, valproate, and lamotrigine are not typically associated with addiction or dependence. Thus, this is not a broad concern for all antiepileptic medications.

B. Most patients will develop anaphylaxis to first-line antiepileptic medications

Although anaphylaxis is a severe allergic reaction that can occur with any medication, it is not common with first-line antiepileptic medications. The incidence of anaphylaxis is quite rare in antiepileptic drugs, and the more common side effects tend to involve sedation, drowsiness, or gastrointestinal disturbances, rather than anaphylaxis. Therefore, this is not a typical concern when prescribing antiepileptics.

C. Most antiepileptics need to be dosed based on height and weight

The dosing of antiepileptics is not generally based on height and weight, except in specific cases such as in children or patients with specific conditions. Most adult patients receive standard dosing regimens that are adjusted based on serum drug levels and the patient's clinical response, not necessarily their height and weight. For example, phenytoin and valproate are dosed primarily based on blood levels to ensure therapeutic efficacy while avoiding toxicity.

Correct Answer: C. Hypotension

Explanation:

Nitroglycerin is a vasodilator commonly used to treat angina (chest pain) by relaxing the blood vessels, which reduces the heart's workload and oxygen demand. One of the primary adverse effects of IV nitroglycerin is hypotension. Since nitroglycerin causes vasodilation, it can lower blood pressure, especially if administered too quickly or in high doses. This drop in blood pressure is typically expected and managed by careful titration of the drug. If blood pressure becomes too low, it can lead to dizziness, fainting, or even shock in severe cases.

Why the Other Options Are Incorrect:

A. Altered mental status

While altered mental status can be a side effect of many medications, it is not commonly associated with nitroglycerin. Hypotension, especially when significant, could lead to dizziness or confusion, but altered mental status is not a direct or typical side effect of IV nitroglycerin.

B. Nausea

Although nausea can occur with many medications, it is not a typical or primary side effect of nitroglycerin. Nausea is more commonly linked to medications that affect the gastrointestinal system, such as opioids or certain antibiotics, rather than vasodilators like nitroglycerin.

D. Bradycardia

Bradycardia (abnormally slow heart rate) is not a common adverse effect of nitroglycerin. While nitroglycerin primarily affects the blood vessels, it does not usually directly influence heart rate in a way that would lead to bradycardia. However, reflex tachycardia (an increased heart rate) may occur due to the blood pressure drop caused by the medication.

Correct Answer: A. Anticholinergics

Explanation:

Anticholinergics are the first-line pharmacologic treatment for overactive bladder (OAB). These medications work by inhibiting muscarinic receptors in the detrusor muscle of the bladder. By blocking the action of acetylcholine, they reduce involuntary bladder contractions, helping to control symptoms such as urinary urgency, frequency, nocturia, and urge incontinence. Common anticholinergic drugs used for OAB include oxybutynin, tolterodine, solifenacin, and darifenacin. These agents improve bladder capacity and delay the urge to void, thus providing symptom relief.

Why the Other Options Are Incorrect:

B. Cholinergic agonist

Cholinergic agonists stimulate muscarinic receptors, promoting bladder contraction. This action is contraindicated in OAB because it would worsen symptoms by increasing detrusor activity. These agents are typically used for urinary retention, not urgency or incontinence.

C. Alpha one blockers

Alpha-1 blockers work by relaxing the smooth muscle of the bladder neck and prostate, improving urine flow. They are primarily used to treat benign prostatic hyperplasia (BPH) in men. While they may have some benefit in urinary outflow resistance, they are not effective in treating the urgency and frequency seen in OAB and are not considered first-line therapy for this condition.

D. Beta blockers

Beta blockers are used to manage cardiovascular conditions such as hypertension, angina, and arrhythmias. They have no direct effect on bladder function and are not used in the treatment of OAB. Their mechanism of action does not influence the muscarinic receptors or detrusor muscle activity responsible for OAB symptoms.

Correct Answer: A. Diltiazem

Explanation:

Diltiazem is a calcium channel blocker (CCB) that is commonly used to treat dysrhythmias, particularly atrial fibrillation and atrial flutter, as well as supraventricular tachycardia (SVT). It works by inhibiting the influx of calcium into the heart's smooth muscle and conducting tissues, leading to decreased heart rate, decreased conduction through the atrioventricular (AV) node, and lower blood pressure. These actions make diltiazem an appropriate medication for managing dysrhythmias, particularly those originating above the ventricles.

Why the Other Options Are Incorrect:

B. Nicardipine

Nicardipine is a calcium channel blocker that primarily works on vascular smooth muscle to dilate arteries and reduce blood pressure. It is not typically used for treating dysrhythmias, as its primary effect is on blood pressure and vascular tone, rather than directly on the conduction system of the heart. While it can be used for hypertensive crises, it is not the first-line choice for dysrhythmias.

C. Amlodipine

Amlodipine is also a calcium channel blocker, but it primarily works by relaxing vascular smooth muscle, leading to vasodilation and lower blood pressure. It is primarily used for treating hypertension and angina, not for dysrhythmias. Like nicardipine, amlodipine has minimal effects on the heart's conduction system and is not appropriate for managing dysrhythmias

D. Labetalol

Labetalol is a beta-blocker and alpha-blocker, not a calcium channel blocker. While it is effective for hypertension and can help control heart rate through its beta-blocking effects, it is not a calcium channel blocker and is not typically used to treat dysrhythmias in the way that diltiazem is. It can be used in some cases for rate control, but it works through a different mechanism.

Correct Answer: D. Alpha pressors

Explanation:

In the treatment of chronic heart failure (CHF), the goal is to improve heart function, manage symptoms, and prevent further complications. The appropriate medication classes for heart failure generally include beta blockers, diuretics, and ACE inhibitors (ACEI) or angiotensin II receptor blockers (ARBs).

Why the Other Options Are Correct:

A. Beta blockers

Beta blockers are a cornerstone in the management of chronic heart failure. They work by blocking beta-adrenergic receptors, which helps reduce the heart rate and the workload on the heart. Beta blockers, such as carvedilol, metoprolol, and bisoprolol, have been shown to reduce morbidity and mortality in patients with heart failure by improving heart function, preventing arrhythmias, and reducing hospitalizations.

B. Diuretics

Diuretics, such as furosemide or spironolactone, are used in the treatment of chronic heart failure to reduce fluid retention, which is a common symptom of the condition. Diuretics help relieve symptoms such as edema, pulmonary congestion, and shortness of breath by promoting the excretion of sodium and water through the kidneys, thus reducing the overall fluid burden on the heart.

C. ACEI/ARB

Angiotensin-converting enzyme inhibitors (ACEIs), such as enalapril or lisinopril, and angiotensin II receptor blockers (ARBs), such as losartan or valsartan, are commonly used in heart failure to block the effects of the renin-angiotensin-aldosterone system (RAAS). These drugs help reduce blood pressure, prevent cardiac remodeling, and improve survival. ACEIs and ARBs are foundational in the treatment of heart failure with reduced ejection fraction (HFrEF).

Why the Correct Answer is Incorrect:

D. Alpha pressors

Alpha pressors, such as phenylephrine or norepinephrine, are vasoconstrictors that work by stimulating alpha-adrenergic receptors to increase blood pressure. These medications are typically used in acute settings for shock or severe hypotension, not in the management of chronic heart failure. In fact, alpha pressors would not be appropriate for chronic heart failure because they increase afterload (the resistance the heart has to pump against), which can worsen the condition by increasing the workload on an already struggling heart. Chronic heart failure treatment focuses on reducing workload and improving heart efficiency, not increasing it.

Correct Answer: C. Nitrofurantoin

Explanation:

C. Nitrofurantoin

Nitrofurantoin is considered a first-line treatment for uncomplicated cystitis in women, as recommended by clinical guidelines such as those from the Infectious Diseases Society of America (IDSA). It is effective against the most common urinary pathogens, particularly Escherichia coli, and has minimal resistance in many communities. It is well tolerated, concentrates in the urine, and causes fewer systemic side effects compared to other antibiotics. Nitrofurantoin is typically prescribed for a 5-day course and is contraindicated in patients with significantly impaired renal function.

Why the Other Options Are Incorrect:

A. Ciprofloxacin

Although ciprofloxacin is effective against many urinary pathogens, fluoroquinolones are not recommended as first-line therapy for uncomplicated cystitis due to their risk profile—including the potential for tendon rupture, neuropathy, and QT prolongation—and the increasing issue of antibiotic resistance. They should be reserved for cases where other safer options are not appropriate.

B. Azithromycin

Azithromycin is a macrolide antibiotic typically used for respiratory tract infections and some sexually transmitted infections. It is not effective against the typical pathogens causing uncomplicated urinary tract infections and is not recommended for cystitis.

D. Cefepime

Cefepime is a fourth-generation cephalosporin used primarily in hospital settings for serious infections, including those caused by multidrug-resistant organisms. It is not appropriate for uncomplicated cystitis and is far too broad-spectrum for outpatient treatment.

Correct Answer: A. Escitalopram

Explanation:

In treating moderate depression in adolescents and young adults, selective serotonin reuptake inhibitors (SSRIs) are often considered the first-line medication due to their efficacy and relatively favorable side effect profile compared to other classes of antidepressants. Among the SSRIs, escitalopram is an effective and commonly prescribed option. It works by increasing the levels of serotonin in the brain, which helps to improve mood and reduce symptoms of depression.

Why the Other Options Are Incorrect:

B. Olanzapine

Olanzapine is an atypical antipsychotic, primarily used to treat schizophrenia and bipolar disorder. It is not first-line treatment for depression, particularly in the context of moderate depression without other complicating factors such as psychotic features. Olanzapine may be used in certain cases of treatment-resistant depression when combined with an antidepressant, but it is not appropriate as a first-line treatment for depression.

C. Wellbutrin

Wellbutrin (or bupropion) is an atypical antidepressant and is an effective option for some individuals with depression. It works by increasing the levels of dopamine and norepinephrine in the brain. However, bupropion is generally avoided in younger patients due to the risk of seizures, which is higher in those under 25, especially in those with eating disorders or a history of seizure disorders. While it can be effective for depression and seasonal affective disorder, it may not be the safest first-line option for a 19-year-old with moderate depression.

D. Duloxetine

Duloxetine is a serotonin-norepinephrine reuptake inhibitor (SNRI). It is also used for depression and anxiety disorders. However, SNRIs are generally considered second-line treatments for depression after SSRIs due to their potential for more side effects, including increased blood pressure and nausea. Additionally, while duloxetine can be a good choice for certain patients, it is not the first medication to initiate in a 19-year-old with moderate depression.

Correct Answer: C. Protamine Sulfate

Explanation:

Protamine sulfate is the reversal agent for heparin. It works by binding to heparin and neutralizing its anticoagulant effects. Protamine sulfate is used in cases of heparin overdose or hemorrhage in patients receiving heparin therapy, as it effectively reverses the anticoagulant effects of heparin and can help control bleeding.

Why the Other Options Are Incorrect:

A. Idarucizumab

Idarucizumab is the reversal agent for dabigatran, which is a direct thrombin inhibitor. It is not used for reversing the effects of heparin. Idarucizumab binds to dabigatran, effectively neutralizing its anticoagulant effects.

B. Warfarin

Warfarin is an oral anticoagulant and not a reversal agent. It is not used to reverse the effects of heparin. Instead, warfarin itself may require reversal using vitamin K or prothrombin complex concentrates (PCC) in the case of a hemorrhage or overdose.

D. Vitamin K

Vitamin K is the reversal agent for warfarin overdose or bleeding caused by warfarin therapy, as it helps in the synthesis of vitamin K-dependent clotting factors. However, it does not affect the action of heparin. Protamine sulfate is the appropriate reversal agent for heparin.

Correct Answer: B. Decrease dose

Explanation:

The TSH (Thyroid Stimulating Hormone) level is used to evaluate thyroid function and guide the adjustment of levothyroxine, a synthetic form of thyroid hormone used to treat hypothyroidism. Typically, a normal TSH level ranges from 0.4 to 4.0 mU/L, but this can vary slightly depending on the lab.

A TSH level of 0.1 mU/L is considered subnormal and indicates that the patient’s thyroid hormone levels may be too high. This could suggest that the levothyroxine dose is too high, leading to a suppressed TSH, which is often a sign of over-treatment. Over-treatment with thyroid hormone can lead to symptoms of hyperthyroidism such as palpitations, weight loss, insomnia, and anxiety. In this case, the APRN would decrease the levothyroxine dose to bring the TSH level back within the appropriate range, which is generally between 0.4 and 4.0 mU/L, depending on the individual patient’s clinical status.

Why the Other Options Are Incorrect:

A. Increase dose

If the TSH level is low (0.1 mU/L), this indicates that the current dose of levothyroxine is too high, not too low. Increasing the dose would further suppress the TSH and may lead to hyperthyroidism, which is not recommended.

C. Recommend no change

With a TSH level of 0.1 mU/L, it is important to adjust the levothyroxine dose to avoid the potential complications of hyperthyroidism. In this case, recommending no change would not be appropriate since the patient is likely receiving too much thyroid hormone.

D. Add methimazole

Methimazole is used to treat hyperthyroidism by inhibiting thyroid hormone production. However, in this scenario, the patient is taking levothyroxine, which is for hypothyroidism. Adding methimazole is not appropriate since the patient’s low TSH suggests over-treatment with thyroid hormone, not hyperthyroidism. The appropriate action is to adjust the levothyroxine dose, not to add methimazole.