Katzung (Smooth Muscle) Flashcards

1
Q
A

(B) Episodes of bronchospasm

Serotonin causes bronchospasm, but the other effects listed are not observed. Carcinoid is associated with diarrhea and hypertension. The answer is B.

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2
Q
A

(A) Epinephrine

The smooth muscle manifestations of angioneurotic edema are mediated by histamine at H, receptors and other mediators of immediate allergy. Fexofenadine is a pharmacologic antagonist of histamine at these receptors with low CNS effect but has a slow onset of action. Promethazine is an older H, antagonist used prophylactically to prevent postsurgical and chemotherapy-induced vomiting. Ranitidine is a phar-macologic histamine antagonist that blocks the H, receptor in the stomach and the heart, not H, receptors in smooth muscle. Tegaserod is a 5-HT4 partial agonist used in irritable bowel syndrome. Epinephrine has a rapid physiologic antagonist action that reverses histamine’s effects on smooth muscle.
The answer is A.

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3
Q
A

(D) Sedation

H1 blockers do not activate muscarinic receptors, mediate vasoconstriction, or cause vertigo. Some relieve vertigo or motion sickness. They do not cause nervousness or anxi-ety. Diphenhydramine is a potent sedative with Hi- and M3-blocking actions. The answer is D.

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4
Q
A

(C) Decreased CAMP in gastric mucosa

H2 receptors are G-protein-coupled receptors, like ß adre-noceptors. Blockade of this system will cause a decrease in cAMP in several tissues. The answer is C.

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5
Q

Refer to Table 16-3. Fenfluramine, a serotonin releasing agent and 5-HT2 agonist, is now banned because it causes pulmonary hypertension and cardiac valve malfunction.
Phentermine has an amphetamine-like action. Naltrexone is a long-acting opioid antagonist; bupropion is an antidepres-sant. Liraglutide is a GLP-1 agonist with antiappetite effects.
Orlistat is an inhibitor of intestinal lipase. The answer is A.

A

(A) Activation of 5-HT2 receptor

Refer to Table 16-3. Fenfluramine, a serotonin releasing agent and 5-HT2 agonist, is now banned because it causes pulmonary hypertension and cardiac valve malfunction.
Phentermine has an amphetamine-like action. Naltrexone is a long-acting opioid antagonist; bupropion is an antidepres-sant. Liraglutide is a GLP-1 agonist with antiappetite effects.
Orlistat is an inhibitor of intestinal lipase. The answer is A.

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6
Q
A

(E) Ondansetron

Ondansetron and other 5-HT antagonists have significant antiemetic effects. Diphenhydramine and prednisone are also used for this purpose. The answer is E.

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7
Q
A

(A) Cyproheptadine

  1. Dantrolene is useful in malignant hyperthermia, a syndrome associated with volatile anesthetics and succinylcholine. Diphen- hydramine is used parenterally in neuroleptic malignant syn- drome, a hyperthermic syndrome associated with antipsychotic agents. Lasmiditan is a new 5-HT 1F antagonist used in migraine.

Ranitidine is an H, blocker used in gastroesophageal reflux dis-order. Cyproheptadine, a 5-HT, antagonist, is potentially useful in serotonin syndrome, see Table 16-2. The answer is A.

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8
Q
A

(A) Bromocriptine

Bromocriptine is an effective dopamine agonist in the pituitary with the advantage of oral activity. The drug inhibits prolactin secretion by activating pituitary dopamine recep-tors. The answer is A.

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9
Q
A

(G) Sumatriptan

Sumatriptan, an agonist at 5-HTID/B receptors, is indicated for prevention or treatment of migraine and cluster head-aches. Ergotamine (not on the list) is also effective for acute migraine but is produced by the fungus Claviceps purpured.
The answer is G.

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10
Q
A

(F) Nitroprusside

A very powerful vasodilator is necessary to reverse ergot-induced vasospasm; nitroprusside is such a drug (see Chapter 11). The answer is F

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11
Q

Field workers exposed to a plant toxin develop painful fluid-filled blisters. Analysis of the blister fluid reveals high concentrations of a peptide. Which of the following is a peptide that causes increased capillary permeability and edema?
(A) Angiotensin lI
(B) Bradykinin
(C) Captopril
(D) Histamine
(E) Sacubitril

A

(B) Bradykinin

  1. Histamine and bradykinin both cause a marked increase in capillary permeability that is often associated with edema, but histamine is not a peptide. The answer is B
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12
Q

In a laboratory study of several peptides, one is found that decreases peripheral resistance but constricts veins.
Which of the following causes arteriolar vasodilation and venoconstriction?
(A) Atrial natriuretic peptide (ANP)
(B) Bradykinin
(C) Endothelin-1
(D) Substance P
(E) Vasoactive intestinal peptide

A

(D) Substance P

Substance P is a potent arterial vasodilator and venoconstric-tor. The answer is D.

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13
Q

Which of the following endogenous molecules is elevated in heart failure and when given as a drug is a vasodilator with significant renal toxicity?
(A) Angiotensin I
(B) Angiotensin II
(C) BNP (nesiritide)
(D) Histamine
(E) Vasoactive intestinal peptide

A

(C) BNP (nesiritide)

BNP is an atrial and brain peptide found in increased amounts in patients with heart failure. The commercial formulation (nesiritide) is approved for use in severe acute heart failure but has significant renal toxicity. The answer is C.

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14
Q

A 50-year-old factory worker presents with cardio-respiratory symptoms and careful workup reveals idiopathic pulmonary hypertension. Which of the following binds endothelin receptors and is approved for use in pulmonary hypertension?
(A) Aliskiren
(B) Capsaicin
(C) Conivaptan
(D) Macitentan
(E) Sacubitril

A

(D) Macitentan

Aliskiren, a renin inhibitor, is used in primary hypertension.
Capsaicin, the “hot” constituent of hot peppers, is the molecule responsible for release of substance P. Conivaptan, an AVP antagonist, is used in hyponatremia. Sacubitril, a neprilysin antagonist, is used in heart failure. Macitentan, an endothelin antagonist, is used in pulmonary hypertension. The answer is D.

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15
Q

A 60-year-old financial consultant presents with severe pain in a neuronal dermatome region of her chest. This area was previously affected by a herpes zoster rash. Which of the following might be of benefit in controlling this postherpetic pain?
(A) Aliskiren
(B) Aprepitant
(C) Bosentan
(D) Capsaicin
(E) Captopril
(F) Losartan
(G) Macitentan

A

(D) Capsaicin

Substance P is an important pain-mediating neurotransmitter peptide and appears to be involved in postherpetic pain as well as arthritic pain. Capsaicin can be used topically to deplete substance P stores from sensory nerves. The answer is D.

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16
Q
  1. In a phase 2 clinical trial in hypertensive patients, an endogenous octapeptide vasoconstrictor was found to increase in the blood of patients treated with large doses of diuretics. Which of the following is the most likely endogenous peptide?
    (A) Angiotensin I
    (B) Angiotensin II
    (C) Atrial natriuretic peptide
    (D) Bradykinin
    (E) Calcitonin gene-related peptide
    (F) Endothelin
    (G) Neuropeptide Y
    (H) Substance P
    (I) Vasoactive intestinal peptide (VIP)
A

(B) Angiotensin II

Angiotensin Il, an octapeptide, increases when blood volume decreases (a diuretic effect) because the compensatory response causes an increase in renin secretion. Its precursor, angiotensin I, would also increase, but it is a decapeptide. The answer is B.

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17
Q
  1. Which of the following is a vasodilator that increases in the blood or tissues of patients treated with captopril?
    (A) Angiotensin II
    (B) Bradykinin
    (C) Brain natriuretic peptide
    (D) Calcitonin gene-related peptide
    (E) Endothelin
    (F) Neuropeptide Y
    (G) Vasopressin (AVP)
A

(C) Brain natriuretic peptide

Bradykinin increases because the enzyme inhibited by captopril, angiotensin-converting enzyme, degrades kinins in addition to synthesizing angiotensin II (see Figure 11-3). The answer is B.

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18
Q
  1. Which of the following is an antagonist at NK, receptors and is used to prevent or reduce chemotherapy-induced nausea and vomiting?
    (A) Angiotensin I
    (B) Aprepitant
    (C) Bosentan
    (D) Bradykinin
    (E) Brain natriuretic peptide
    (F) Enalapril
    (G) Ondansetron
A

(C) Bosentan

Aprepitant and ondansetron are both used to reduce or prevent chemotherapy-induced nausea and vomiting. Ondanse-tron is an antagonist at 5-HT receptors. The answer is B.

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19
Q
  1. A 35-year-old industrial designer suffers frequent disabling migraine headaches. Her neurologist suggests that she try a Whily at the ruling mo in alran desis poni def
    the proposed drug in migraine?
    (A) Capsaicin interferes with the action of angiotensin II on the AT, receptor
    (B) Erenumab inhibits the CGRP receptor
    (C) Ecallantide irreversibly inhibits the synthesis of bradykinin
    (D) Macitentan interferes with the action of vasoactive intestinal peptide at the NK, receptor
    (E) Sacubitril inhibits the synthesis of CGRP
A

(B) Erenumab inhibits the CGRP receptor

Capsaicin inhibits substance P and is used to reduce the pain of arthritis and postherpetic pain. Ecallantide blocks bradykinin B, receptor and is used in angioedema. Macitentan blocks ET and ET receptors and is used in pulmonary hyperten-sion. Sacubitril inhibits neprilysin and is indicated for heart failure. Erenumab blocks the CGRP receptor and is administered by subcutaneous injection once per month for migraine prophylaxis. The answer is B

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20
Q
  1. A patient is admitted to the emergency department in coma.
    Laboratory tests reveal a plasma sodium concentration of 110 mEq/L (normal 135-145 mEq/L). Which of the following drugs might be used to correct this hyponatremia?
    (A) Aliskiren
    (B) Furosemide
    (C) Macitentan
    (D) Tolvaptan
    (E) Vasopressin
A

(D) Tolvaptan

Severe hyponatremia is potentially lethal and requires urgent treatment. Aliskiren, a renin inhibitor, is used in heart failure.
Furosemide, a loop diuretic, increases the excretion of salt as well as water and is potentially dangerous in hyponatremia. Maciten-tan is valuable in pulmonary hypertension, not hyponatremia.
Vasopressin inhibits the excretion of water and is contraindicated in hyponatremia. Tolvaptan is a vasopressin antagonist and is a drug of choice in hyponatremia. The answer is D.

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21
Q
  1. Which drug class reduces the effects of the renin-angiotensin-aldosterone system to lower blood pressure?
    a) ACE inhibitors
    b) Beta-blockers
    c) Calcium channel blockers
    d) Diuretics
A

a) ACE inhibitors
Rationale: ACE inhibitors, such as captopril, act by reducing the effects of the renin-angiotensin-aldosterone system, leading to a decrease in blood pressure.

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22
Q
  1. Which drug is associated with an increased level of bradykinin in the circulation?
    a) Losartan
    b) Atenolol
    c) Captopril
    d) Hydrochlorothiazide
A

c) Captopril
Rationale: ACE inhibitors, like captopril, increase circulating levels of bradykinin because ACE usually inactivates bradykinin.

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23
Q
  1. Which side effect is believed to be due to the elevated levels of bradykinin from ACE inhibitor use?
    a) Diarrhea
    b) Cough
    c) Headache
    d) Dizziness
A

b) Cough
Rationale: An increased level of bradykinin due to ACE inhibitor use is believed to be responsible for the high incidence of cough seen with these drugs.

24
Q
  1. What substance is synthesized as a result of increased bradykinin, believed to cause cough in ACE inhibitor users?
    a) Renin
    b) Prostaglandins
    c) Angiotensin I
    d) Aldosterone
A

b) Prostaglandins
Rationale: The cough seen with ACE inhibitor use is believed to arise from prostaglandins produced due to elevated bradykinin levels.

25
Q
  1. Which class of drugs has a lower incidence of cough compared to ACE inhibitors?
    a) Diuretics
    b) Beta-blockers
    c) AT1-receptor blockers
    d) Calcium channel blockers
A

c) AT1-receptor blockers
Rationale: AT1-receptor blockers, such as losartan and valsartan, do not increase bradykinin levels, resulting in a lower incidence of cough compared to ACE inhibitors.

26
Q
  1. Which of the following drugs does NOT interfere with fetal renal development?
    a) Atenolol
    b) Captopril
    c) Losartan
    d) Both b and c
A

a) Atenolol
Rationale: Both ACE inhibitors (like captopril) and AT1-receptor blockers (like losartan) interfere with fetal renal development and are contraindicated during pregnancy.

27
Q
  1. Which drug is an example of an AT1-receptor blocker?
    a) Amlodipine
    b) Captopril
    c) Valsartan
    d) Furosemide
A

c) Valsartan
Rationale: Valsartan is an example of an AT1-receptor blocker.

28
Q
  1. ACE inhibitors lead to a compensatory increase in the release of:
    a) Bradykinin
    b) Aldosterone
    c) Renin and Angiotensin I
    d) Prostaglandins
A

c) Renin and Angiotensin I
Rationale: ACE inhibitors result in a compensatory increase in the release of renin and angiotensin I.

29
Q
  1. Which of the following is a primary mechanism of action for Losartan?
    a) Increasing bradykinin
    b) Blocking AT1 receptors
    c) Inhibiting ACE
    d) Stimulating renin release
A

b) Blocking AT1 receptors
Rationale: Losartan is an AT1-receptor blocker, so its primary mechanism of action is blocking AT1 receptors.

30
Q
  1. Which of the following is contraindicated during pregnancy due to interference with fetal renal development?
    a) Calcium channel blockers
    b) Diuretics
    c) ACE inhibitors
    d) Beta-blockers
A

c) ACE inhibitors
Rationale: ACE inhibitors, like captopril, interfere with fetal renal development and are contraindicated during pregnancy.

31
Q
  1. A 35-year-old woman with moderately severe arthritis has been treated with nonsteroidal anti-inflammatory drugs for 6 months. Her arthritis symptoms have been well controlled.
    She now complains of heartburn and indigestion. You give her a prescription for a drug to be taken along with the anti-inflam-matory agent, but 2 days later she calls the office complaining that your last prescription has caused severe diarrhea and cramping that resembles her periods. Which of the following is most likely to be associated with increased gastrointestinal motility and uterine cramping?
    (A) Aspirin
    (B) Famotidine
    (C) Leukotriene LTB4
    (D) Misoprostol
    (E) Zileuton
A

(D) Misoprostol

Aspirin and zileuton rarely cause diarrhea.
LTB is a chemo-tactic factor.
Famotidine is an H2 blocker that does not cause diarrhea.
Misoprostol, a PGE1 analog with protective effects on gastric mucosa, increases gastrointestinal and uterine motility. It is sometimes used as part of an abortifacient.

32
Q

Which mechanism explains aspirin’s inhibition of thrombox-ane synthesis?
(A) Blocks cyclooxygenase
(B) Blocks lipoxygenase
(C) Blocks phospholipase A2
(D) Blocks PGE1 receptors
(E) Blocks PGI2 receptors

A

(A) Blocks cyclooxygenase

Hydrocortisone and other corticosteroids inhibit phospholipase.
Ibuprofen and indomethacin inhibit cyclooxygenase reversibly.
Zileuton inhibits lipoxygenase.
Aspirin inhibits cyclooxygenase irreversibly and is more effective in platelets.

33
Q

A 57-year-old man has severe pulmonary hypertension and right ventricular hypertrophy. Which of the following agents causes vasodilation and may be useful in pulmonary hypertension?
(A) Acetylcholine
(B) Bradykinin
(C) Prostaglandin PGF2a
(D) Prostacyclin
(E) Thromboxane

A

(D) Prostacyclin

Prostacyclin (PGI2) is a potent vasodilator.
Acetylcholine and bradykinin cause generalized vasodilation but are not useful in pulmonary or systemic hypertension.
PGF2α and thromboxane are vasoconstrictors.

34
Q

A 19-year-old woman complains of severe dysmenorrhea. A uterine stimulant derived from membrane lipid in the endometrium is
(A) Angiotensin II
(B) Oxytocin
(C) Prostacyclin (PGI2)
(D) Prostaglandin PGF2a
(E) Serotonin

A

(D) Prostaglandin PGF2a

Serotonin and histamine may cause uterine stimulation but are not derived from membrane lipid.
Oxytocin causes uterine contraction but is a peptide hormone.
Prostacyclin relaxes the uterus.

34
Q

Inflammation is a complex tissue reaction that includes the release of cytokines, leukotrienes, prostaglandins, and pep-tides. Leukotrienes involved in inflammatory processes are typically produced from arachidonic acid by which of the following enzymes?
(A) Cyclooxygenase-1
(B) Cyclooxygenase-2
(C) Glutathione-S-transferase
(D) Lipoxygenase
(E) Phospholipase A2

A

(D) Lipoxygenase

Phospholipase A2 converts membrane phospholipid to arachidonic acid.
Cyclooxygenases convert arachidonic acid to prostaglandins.
COX-1 products are important in normal physiologic processes.
Lipoxygenase produces leukotrienes from arachidonic acid in inflammatory cells.

35
Q

A newborn infant is diagnosed with transposition of the great vessels, wherein the aorta exits from the right ventricle and the pulmonary artery from the left ventricle. Which of the following drugs is likely to be used in preparation for surgical correction of this anomaly?
(A) Aspirin
(B) Leukotriene LTC4
(C) Prednisone
(D) Prostaglandin PGE1
(E) Prostaglandin PGE2a

A

(D) Prostaglandin PGE1

Infants with great vessel transposition require surgical correction and depend on a patent ductus arteriosus to allow oxygenated blood flow.
PGE1 can keep the ductus open.
Aspirin is contraindicated in this condition as it reduces the production of endogenous PGE1.

36
Q

A patient with a positive fecal blood test is referred to the gastroenterology clinic. He is apparently taking large amounts of an unidentified drug that inhibits platelet activity. Which of the following is taken orally and directly and reversibly inhibits platelet cyclooxygenase?
(A) Alprostadil
(B) Aspirin
(C) Ibuprofen
(D) Leukotriene LTC4
(E) Misoprostol
(F) Prednisone
(G) Prostacyclin
(H) Zafirlukast
(I) Zileuton

A

(C) Ibuprofen

Aspirin is a direct and irreversible inhibitor of cyclooxygenase.
Other NSAIDs like ibuprofen are reversible inhibitors of COX.
Corticosteroids reduce the synthesis of cyclooxygenase.

37
Q

Which of the following is a component of slow-reacting substance of anaphylaxis (SRS-A)?
(A) Alprostadil
(B) Aspirin
(C) Leukotriene LTB4
(D) Leukotriene LTC4
(E) Misoprostol
(F) Prednisone
(G) Prostacyclin
(H) Zafirlukast
(I) Zileuton

A

(D) Leukotriene LTC4

Leukotriene C and D series are major components of SRS-A.
Leukotriene LTB4 is a chemotactic eicosanoid.

38
Q

A 17-year-old patient complains that he develops wheezing and severe shortness of breath whenever he takes aspirin for headache. Increased levels of which of the following may be responsible, in part, for some cases of aspirin hypersensitivity?
(A) Alprostadil
(B) Hydrocortisone
(C) Ibuprofen
(D) Leukotriene LTC4
(E) Misoprostol
(F) PGE2
(G) Prostacyclin
(H) Thromboxane
(1) Zileuton

A

(D) Leukotriene LTC4

When cyclooxygenase is blocked, leukotrienes may be produced in increased amounts due to diversion of prostaglandin precursors into the lipoxygenase pathway.
This can precipitate bronchoconstriction in aspirin hypersensitivity.

39
Q

Which of the following is a leukotriene receptor blocker?
(A) Alprostadil
(B) Aspirin
(C) Ibuprofen
(D) Leukotriene LTC4
(E) Montelukast
(F) Prednisone
(G) Prostacyclin
(H) Zileuton

A

(E) Montelukast

Explanation:

Zileuton blocks the synthesis of leukotrienes.
Montelukast and zafirlukast block LTD4 receptors.

40
Q

Which one of the following is not a nitric oxide (NO) donor but causes it to be synthesized and released from endogenous precursors, resulting in vasodilation?
(A) Acetylcholine
(B) Arginine
(C) Isosorbide mononitrate
(D) Nitroglycerin
(E) Nitroprusside

A

(A) Acetylcholine

Nitroprusside, organic nitrites (e.g., amyl nitrite), and nitrates (e.g., nitroglycerin, isosorbide dinitrate, and isosorbide mononitrate) contain NO groups that can be released as nitric oxide (NO).
Arginine is the normal source of endogenous NO.
Acetylcholine, acting on M3 receptors, stimulates the synthesis of NO from arginine.

41
Q

An NO-containing molecule that releases nitric oxide in the blood is
(A) Citrulline
(B) Histamine
(C) Isoproterenol
(D) Nitroglycerin
(E) Nitroprusside

A

(E) Nitroprusside

Nitroprusside is the only molecule in the list that spontaneously releases nitric oxide (NO) in the bloodstream. It is used as a potent vasodilator in clinical settings.

42
Q

The inducible isoform of nitric oxide synthase (iNOS, isoform 2) is found primarily in which of the following?
(A) Adipose tissue
(B) Eosinophils
(C) Macrophages
(D) Neurons
(E) Platelets

A

(C) Macrophages

The inducible form of nitric oxide synthase (NOS) is associated with inflammation, and the enzyme is found in the highest concentration in macrophages, which play a significant role in inflammation.

43
Q

The primary endogenous substrate for the enzyme nitric oxide synthase (NOS) is
(A) Acetylcholine
(B) Angiotensinogen
(C) Arginine
(D) Citrulline
(E) Heme

A

(C) Arginine

Arginine is the substrate for NOS, and citrulline and nitric oxide (NO) are the products when NOS acts on arginine.

44
Q

Which of the following is a recognized effect of NO?
(A) Arrhythmia
(B) Bronchoconstriction
(C) Constipation
(D) Inhibition of acute graft rejection
(E) Pulmonary vasodilation

A

(E) Pulmonary vasodilation

Nitric oxide (NO) does not cause arrhythmias or constipation.
It does cause bronchodilation and may hasten graft rejection.
NO also causes pulmonary vasodilation.

45
Q

Which of the following binds soluble guanylyl cyclase and increases the effect of NO on smooth muscle?
(A) Arginine
(B) Angiotensinogen
(C) Nitroprusside
(D) Riociguat
(E) Thromboxane

A

(D) Riociguat

Riociguat is a medication that sensitizes soluble guanylate cyclase (sGC) and increases the effect of nitric oxide (NO). It is used to treat pulmonary hypertension.

46
Q

One effect that theophylline, nitroglycerin, isoproterenol, and histamine have in common is
(A) Direct stimulation of cardiac contractile force
(B) Tachycardia
(C) Bronchodilation
(D) Postural hypotension
(E) Throbbing headache

A

(B) Tachycardia

Theophylline does not typically cause headache or postural hypotension.
Nitroglycerin does not cause direct cardiac stimulation but can evoke a compensatory sympathetic reflex.
Histamine does not cause bronchodilation.

47
Q

A 23-year-old woman is using an albuterol inhaler for frequent acute episodes of asthma and complains of symptoms that she ascribes to the albuterol. Which of the following is not a recognized action of albuterol?
(A) Diuretic effect
(B) Positive inotropic effect
(C) Skeletal muscle tremor
(D) Smooth muscle relaxation
(E) Tachycardia

A

(A) Diuretic effect

Albuterol is a beta-2 selective receptor agonist, but in moderate to high doses, it can produce beta-1 mediated cardiac effects as well as beta-2 mediated smooth and skeletal muscle effects.
It does not typically cause diuresis.

48
Q

A 19-year-old college student has well-controlled asthma but on reporting to the college health clinic, complains of a sore throat. On examination, he has typical signs of thrush, a fungal infection with Candida albicans. The asthma controller medication most likely to be associated with Candida infection is:
(A) Albuterol by aerosol
(B) Beclomethasone by aerosol
(C) Ipratropium by inhaler
(D) Prednisone by mouth
(E) Theophylline in long-acting oral form

A

(B) Beclomethasone by aerosol

Chronic oral corticosteroids like prednisone are associated with important toxicities but are unlikely to cause oral fungal infection.
Topical and inhaled steroids, like beclomethasone, are more likely to lead to this adverse effect due to high concentrations in the oropharynx.

49
Q

A 16-year-old patient is in the emergency department receiving nasal oxygen. She has a heart rate of 125 bpm, a respiratory rate of 40 breaths/min, and a peak expiratory flow <50% of the predicted value. Wheezing and rales are audible without a stethoscope.

Which of the following drugs can be used by nebulizer for a prompt direct bronchodilator effect in severe, acute asthma?
(A) Albuterol
(B) Ipratropium
(C) Montelukast
(D) Prednisone
(E) Salmeterol

A

(A) Albuterol

Corticosteroids, while important in severe chronic asthma and status asthmaticus, do not have a demonstrable direct bronchodilator action.
Salmeterol has a slow onset of action and is not suitable for an acute asthmatic attack.
Ipratropium has bronchodilator action but is not the drug of first choice.

50
Q

A 16-year-old patient is in the emergency department receiving nasal oxygen. She has a heart rate of 125 bpm, a respiratory rate of 40 breaths/min, and a peak expiratory flow <50% of the predicted value. Wheezing and rales are audible without a stethoscope.

After successful treatment of the acute attack, the patient was referred to the outpatient clinic for follow-up treatment for asthma. Which of the following is not an established prophylactic strategy for asthma?
(A) Avoidance of antigen exposure
(B) Blockade of histamine receptors
(C) Blockade of leukotriene receptors
(D) IL-5 cytokine blockade
(E) Inhibition of phospholipase A2

A

(B) Blockade of histamine receptors

Histamine does not play a significant role in asthma, and antihistaminic drugs, even in high doses, are of little or no value.
Antigen avoidance is established as a useful approach.
Blockade of leukotriene receptors with montelukast or zafirlukast, inhibition of phospholipase with corticosteroids, and inhibition of cytokines are also useful.

51
Q

Mr Green is a 60-year-old former smoker with cardiac disease and severe chronic obstructive pulmonary disease (COPD), associated with frequent episodes of bronchospasm. Which of the following is a bronchodilator useful in COPD and least likely to cause cardiac arrhythmia?
(A) Aminophylline
(B) Cromolyn
(C) Epinephrine
(D) Ipratropium
(E) Metaproterenol
(F) Metoprolol
(G) Prednisone
(H) Salmeterol
(I) Zafirlukast
(J) Zileuton

A

(D) Ipratropium

Ipratropium or a similar antimuscarinic agent is the bronchodilator most likely to be useful in COPD without causing arrhythmias.

52
Q

A 22-year-old man is brought to the emergency department after suffering seizures resulting from an overdose of a drug he has been taking. His friends state that he took the drug orally and sometimes had insomnia after taking it. Which of the following is a direct bronchodilator that is most often used in asthma by the oral route and is capable of causing insomnia and seizures?
(A) Cromolyn
(B) Epinephrine
(C) pratropium
(D) Metaproterenol
(E) Metoprolol
(F) Prednisone
(G) Salmeterol
(H) Theophylline
(I) Zileuton

A

(H) Theophylline

Theophylline is an oral bronchodilator that can cause insomnia in therapeutic doses and seizures in overdosage.

53
Q

Which of the following in its parenteral form is lifesaving in severe status asthmaticus and acts, at least in part, by inhibiting phospholipase A2?
(A) Aminophylline
(B) Cromolyn
(C) Epinephrine
(D) Ipratropium
(E) Metaproterenol
(F) Metoprolol
(G) Prednisone
(H) Salmeterol
(I) Zafirlukast
(J) Zileuton

A

(G) Prednisone

Parenteral corticosteroids, such as prednisolone (the active metabolite of prednisone), are lifesaving in status asthmaticus.
They likely act by reducing the production of leukotrienes.

54
Q

Which of the following has a slow onset but long duration of action and is always used in combination with a corticosteroid by inhalation?
(A) Aminophylline
(B) Cromolyn
(C) Epinephrine
(D) Ipratropium
(E) Metaproterenol
(F) Metoprolol
(G) Prednisone/prednisolone
(H) Salmeterol
(I) Zafirlukast
(J) Zileuton

A

(H) Salmeterol

Salmeterol is a beta-2 selective agonist with a slow onset and long duration of action.
Used alone, it increases asthma mortality, but in combination with inhaled corticosteroids prophylactically, it improves asthma control.

55
Q
  1. Oral medications are popular for the treatment of asthma in children because young children may have difficulty with the proper use of aerosol inhalers. Which of the following is an orally active inhibitor of leukotriene receptors?
    (A) Albuterol
    (B) Aminophylline
    (C) Ipratropium
    (D) Zafirlukast
    (E) Zileuton
A

(D) Zafirlukast

Zileuton is an inhibitor of the lipoxygenase enzyme involved in the synthesis of leukotrienes.
Montelukast and zafirlukast are leukotriene antagonists at the leukotriene receptor.