Katzung (Smooth Muscle) Flashcards
(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.
(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.
(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.
(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.
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) 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.
(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.
(A) Cyproheptadine
- 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.
(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.
(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.
(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
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
(B) Bradykinin
- 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
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
(D) Substance P
Substance P is a potent arterial vasodilator and venoconstric-tor. The answer is D.
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
(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.
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
(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.
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
(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.
- 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)
(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.
- 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)
(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.
- 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
(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.
- 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
(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
- 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
(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.
- 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) 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.
- Which drug is associated with an increased level of bradykinin in the circulation?
a) Losartan
b) Atenolol
c) Captopril
d) Hydrochlorothiazide
c) Captopril
Rationale: ACE inhibitors, like captopril, increase circulating levels of bradykinin because ACE usually inactivates bradykinin.