CUMULATIVE PHARMACOLOGY REVIEW SESSION Flashcards
A 68 y/o male presents with heart failure, unacceptably low cardiac output, and intense reflex-mediated sympathetic activation of the peripheral vasculature that is attempting to keep vital organ perfusion pressure sufficiently high. He is edematous, and has ascites, because of the poor cardiac function and renal compensations for it. Which of the following agents should be avoided in this patient because it is most likely to compromise function of the already failing heart and the circulatory system overall? A.Amiloride B.Furosemide C.Hydrochlorothiazide D.Mannitol E.Spironolactone
mannitol
Mannitol (Osmotic Diuretics)
- Increases plasma osmolality initially until it is excreted by glomerular filtration
- Increased plasma osmolality withdraws water from the extracellular space and parenchymal cells into the blood
- If renal function is normal, renal blood flow and GFR rise and mannitol is eventually excreted
- If cardiac function is normal and adequate, circulating the extra volume is not a problem (up to a limit)
- With low cardiac output or compromised renal perfusion, increased blood volume and pressure may cause acute heart failure due to the additional volume and difficulty ejecting that volume against a higher afterload
A 32 y/o male with stage 2 essential hypertension is treated with usually effective doses of an ACE inhibitor. After a suitable period of time blood pressure has not been lowered satisfactorily. He has been compliant with drug therapy and other recommendations (e.g., weight reduction, exercise). A thiazide is added to the ACE inhibitor regimen. Which of the following is the most likely and earliest untoward outcome of this drug add-on, for which you should monitor closely?
A.Fall of blood pressure sufficient to cause syncope
B.Hypokalemia due to synergistic effects of the ACE inhibitor and the thiazide on renal potassium excretion
C.Onset of acute heart failure from depression of ventricular contractility
D.Paradoxical hypertensive crisis
E.Sudden prolongation of the P-R interval and increasing degrees of heart block
hyperkalemia and cough are ae
Fall of blood pressure sufficient to cause syncope
Which of the following statements correctly summarizes how losartan differs from lisinopril or its related drugs?
A.Lisinopril competitively blocks catecholamine-mediated vasoconstriction, losartan does not
B.Lisinopril effectively inhibits synthesis of angiotensin II, losartan does not
C.Losartan causes a higher incidence of bronchospasm and hyperuricemia
D.Losartan is preferred for managing HTN during pregnancy, whereas lisinopril is contraindicated
E.Losartan is suitable for administration to patients with heart failure, whereas lisinopril and related drugs should be avoided
Lisinopril effectively inhibits synthesis of angiotensin II, losartan does not
A 55 y/o male with a 20-year history of type 2 diabetes mellitus comes to your clinic for his regular check-up. Current diabetes medications are metformin and glyburide. He is also taking an HMG-CoA reductase inhibitor to control his lipids and verapamil for Stage 1 hypertension. He looks good and feels well, but his blood pressure is not well controlled. You consider adding another antihypertensive drug. Which comorbidity or other factor would weigh against your selection of an angiotensin converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) as the add-on antihypertensive drug for this patient? A.Bilateral renal artery stenosis B.Bradycardia C.Has had elevated HbA1cin the last year D.Has heart failure E.Is currently taking rosuvastatin
these dialate efferent arterioles
renoprotective as long as renal perfusion is good
BILATERAL ENAL ARTERY STENOSIS
A 65 y/o male presents for a follow-up appointment after taking a drug for symptomatic relief of benign prostatic hypertrophy (BPH). In addition to its effects on smooth muscles of the prostate and urethra, this drug can lower blood pressure in such a way that it triggers reflex tachycardia, positive inotropy, and increased AV nodal conduction. The drug neither dilates nor constricts the bronchi. It causes the pupils of the eyes to constrict and interferes with mydriasisin dim light. Initial oral dosages of this drug have been associated with a high incidence of syncope. Which prototype is most similar to this unnamed drug in terms of the pharmacologic profile? A.Captopril B.Hydrochlorothiazide C.Labetalol D.Prazosin E.Propranolol
prazosin
a1blocker
You are contemplating starting ACE inhibitor therapy for a patient with primary hypertension. Which of the following patient-related condition(s) contraindicates use of and ACE inhibitor and so should be ruled out before you prescribe this drug?
A.Asthma
B.Heart failure
C.Hyperlipidemia, coronary artery disease
D.Hypokalemia
E.Possibility of pregnancy
pregnancy
all raas drugs are out for pregnancy
A 38 y/o female was recently diagnosed with adrenal cortical adenoma. Among the pertinent Cushingoidsigns and symptoms are hypertension and weight gain from fluid retention; and hypernatremia and hypokalemia. Which drug would be the most rationale to prescribe, alone or adjunctively, to specifically antagonize both the renal and the systemic effects of the hormone excess?
A.Acetazolamide B.Amiloride C.Furosemide D.Metolazone E.Spironolactone
reverses hypernatremia and hypokalemia
salt sugar sex
spironolactone
Urinary potassium concentrations are measured before and after several weeks of administering a loop diuretic at typical daily doses. Post-treatment urine potassium concentrations are substantially lower than those measured at baseline. Which of the following is the most likely explanation for this observation?
A.An expected response to the drug
B.Loop diuretics cause potassium-wasting only in in vitroexperimental models
C.Measurements of post-treatment urine potassium concentrations were erroneous
D.The patient has hypoaldosteronismfrom bilateral adrenalectomy
E.The patient has significantly impaired renal function
think about conc not amount
An expected response to the drug
Changes in Urinary Electrolytes and Body pH in Response to Diuretics
Loop agents plus thiazides
NaCl
NaHCO3
K+
Body pH
+++++
+
++
↑
Changes in Urinary Electrolytes and Body pH in Response to Diuretic
K+-sparing agents
NaCl
NaHCO3
K+
Body pH
+
(+)
-
↓
Changes in Urinary Electrolytes and Body pH in Response to Diuretics
Carbonic anhydrase inhibitors
NaCl
NaHCO3
K+
Body pH
+
+++
+
↓
Changes in Urinary Electrolytes and Body pH in Response to Diuretics
Loop agents
NaCl
NaHCO3
K+
Body pH
++++
0
+
↑
Changes in Urinary Electrolytes and Body pH in Response to Diuretics
thiazides
NaCl
NaHCO3
K+
Body pH
++
+
+
↑
Chlorthalidoneand torsemideand members of different diuretic classes, in terms of mechanisms of action and chemical structure, but they share the ability to cause hypokalemia. Which statement best describes the general mechanism by which these drugs cause their effects that lead to net renal potassium loss?
A.Act as aldosterone receptor antagonists, thereby favoring K+loss
B.Block proximal tubular ATP-dependent secretory pumps for K+
C.Increase delivery of Na+ to the distal nephron, where Na+reuptake creates a negative lumen potential that favors K+secretion
D.Stimulate a proximal tubular Na+/K+ATPase such that K+is actively pumped into the urine
E.Lower distal tubular urine osmolality, thereby favoring passive diffusion of K+into the urine
chlorthalidone is a thiazide
Increase delivery of Na+ to the distal nephron, where Na+reuptake creates a negative lumen potential that favors K+secretion