Deck 3: Blood Pressure and Diuretics

Question 1

Methyldopa lowers BP by:

A)Inhibiting dopa decarboxylase in adrenergic nerve endings
B)Generating ?-methyl noradrenaline in brain which reduces sympathetic tone
C)Generating ?-methyl noradrenaline which acts as a false transmitter in peripheral adrenergic nerve endings
D)Activating vascular dopamine receptors

Answer 1

Generating ?-methyl noradrenaline in brain which reduces sympathetic tone

Question 2

Methyldopa differs from clonidine in the following respect:

A)It is less likely to cause rebound hypertension on sudden discontinuation
B)It does not reduce plasma renin activity
C)It has a central as well as peripheral site of antihypertensive action
D)It does not produce central side effects

Answer 2

It is less likely to cause rebound hypertension on sudden discontinuation

Question 3

Used alone the following antihypertensive drug tends to increase cardiac work and can precipitate angina:

A)Clonidine
B)Hydralazine
C)Captopril
D)Prazosin

Answer 3

Hydralazine

Question 4

is a directly acting vasodilator, but is not used alone as an antihypertensive because:

A)By itself, it is a low efficacy antihypertensive
B)Effective doses cause marked postural hypotension
C)Tolerance to the antihypertensive action develops early due to counterregulatory mechanisms
D)It primarily reduces systolic blood pressure with little effect on diastolic blood pressure

Question 5

Long-term hydralazine therapy is likely to cause:

A)Gynaecomastia
B)Thrombocytopenia
C)Haemolytic anaemia
D)Lupus erythematosus

Question 6

The following vasodilator(s) act(s) by opening K⁺ channels in the vascular smooth muscle:

A)Dipyridamole
B)Minoxidil
C)Diazoxide
D)Both 'B' and 'C'

Question 7

Angiotensin converting enzyme inhibitors are contraindicated in:

A)High renin hypertensives
B)Diabetics
C)Congestive heart failure patients
D)Pregnant women

Question 8

Secretion of K⁺ in the late distal tubule and collecting ducts of kidney depends on:

A)Intracellular K⁺ content
B)Unabsorbed Na⁺ load presented to the distal segment
C)Aldosterone level
D)All of the above

Question 9

Metformin belongs to which class?

A)Sulphonylureas
B)Meglitinide analogues
C)Biguanides
D)Thiazolidinediones

Question 10

Diuretics acting on the ascending limb of loop of Henle are the most efficacious in promoting salt and water excretion because:

A)Maximum percentage of salt and water is reabsorbed in this segment
B)Reabsorptive capacity of the segments distal to it is limited
C)This segment is highly permeable to both salt and water
D)This segment is responsible for creating corticomedullary osmotic gradient

Question 11

Furosemide acts by inhibiting the following in the renal tubular cell:

A)Na⁺-K⁺-2Cl^- cotransporter
B)Na⁺-Cl^- symporter
C)Na⁺-H⁺ antiporter
D)Na⁺ K⁺ ATPase

Question 12

Thiazide diuretics and furosemide have directionally opposite effect on the net renal excretion of the following substance:

A)Uric acid
B)Calcium
C)Magnesium
D)Bicarbonate

Question 13

The Na⁺-Cl^- symport in the early distal convoluted tubule of the kidney is inhibited by:

A)Thiazides
B)Metolazone
C)Xipamide
D)All of the above

Question 14

Choose the correct statement about thiazide diuretics:

A)They act in the proximal convoluted tubule
B)They are uricosuric
C)They augment corticomedullary osmotic gradient
D)They induce diuresis in acidosis as well as alkalosis

Question 15

Thiazide diuretics enhance K⁺ elimination in urine primarily by:

A)Inhibiting proximal tubular K⁺ reabsorption
B)Inhibiting Na⁺ K⁺-2Cl^- cotransport in the ascending limb of loop of Henle
C)Increasing the availability of Na+ in the distal tubular fluid to exchange with interstitial K⁺
D)Potentiating the action of aldosterone

Question 16

The primary site of action of thiazide diuretics is:

A)Proximal tubule
B)Ascending limb of loop of Henle
C)Cortical diluting segment
D)Collecting ducts

Question 17

The most important reason for the thiazides being only moderately efficacious diuretics is:

A)About 9/10th of glomerular filtrate is reabsorbed proximal to their site of action
B)Compensatory increase in reabsorption at sites not affected by these drugs
C)They decrease glomerular filtration
D)They have relatively flat dose response curve

Question 18

Given drug is

A)Hydrochlorthiazide
B)Acetazolamide
C)Furosemide
D)Ethacrinic acid

Question 19

Long-term thiazide therapy can cause hyperglycaemia by:

A)Reducing insulin release
B)Interfering with glucose utilization in tissues
C)Increasing sympathetic activity
D)Increasing corticosteroid secretion

Question 20

Which of the following is a potassium retaining diuretic:

A)Triamterene
B)Trimethoprim
C)Tizanidine
D)Trimetazidine

Question 21

Choose the correct statement about osmotic diuretics:

A)They are large molecular weight substances which form colloidal solution
B)Their primary site of action is collecting ducts in the kidney
C)They increase water excretion without increasing salt excretion
D)They can lower intraocular pressure

Question 22

The primary mechanism by which antidiuretic hormone reduces urine volume is:

A)Decrease in glomerular filtration rate
B)Decreased renal blood flow
C)Decreased water permeability of descending limb of loop of Henle
D)Increased water permeability of collecting duct cells

Question 23

The primary mechanism by which heparin prevents coagulation of blood is:

A)Direct inhibition of prothrombin to thrombin conversion
B)Facilitation of antithrombin III mediated inhibition of factor Xa and thrombin
C)Activation of antithrombin III to inhibit factors IX and XI
D)Inhibition of factors XIIa and XIIIa

Question 24

Low concentrations of heparin selectively interfere with the following coagulation pathway(s):

A)Intrinsic pathway
B)Extrinsic pathway
C)Common pathway
D)Both 'A' and 'C'

Question 25

Low doses of heparin prolong:

A)Bleeding time
B)Activated partial thromboplastin time
C)Prothrombin time
D)Both 'B' and 'C'