Pharmacology of Hypertension Flashcards

Question

What is the therapeutic objective for Mrs Turner?

Answer 1

Lower her BP - to reduce risk of long term consequences e.g. cardiovascular related diseases Pain management of her RA

Answer 2

Hypertension medications = no immediate effects Short-term makes you feel worse due to everyday side effects They offer future protection that patients sometimes do not realise V. rarely patients sometimes have hypertensive encephalopathy (general brain dysfunction due to significantly high blood pressure), in which case the medication will have quick short term and long term effects Whereas inhalers = feel better within a few hours

Answer 3

Firstly, give her lifestyle modifications e.g. stop smoking, reduce her BMI etc. Check for diabetes Do an ambulatory 24-hr reading Find out whether she has hypertension, and if she does - stage 1 or stage 2?

Answer 4

Stage 1 = 135-150 systole Stage 2 = 150+ systole Stage 2 = get treated Stage 1 = only get treated if they also have target end organ damage, renal disease, 10 year risk of greater than 10%, CVD or left ventricular hypertrophy

Answer 5

The NICE guidelines for the treatment of hypertension would suggest that Mrs Turner is treated with a calcium channel blocker - >55 y/o and ethnicity (black)

Answer 6

Calcium channel blockers prevent calcium from entering the heart muscle cells Leads to less contractility of the heart and vasodilation Relaxes smooth muscle, reduces resistance of the blood vessels, reduces cardiac output

Answer 7

Clearance = the measure of the ability of the body to eliminate a drug Clearance by means of various organs of elimination is additive Elimination of drug may occur as a result of processes that occur in the liver, kidney, and other organs

Answer 8

Plasma clearance = how much blood goes through the kidney in a given time to filter out the drug Elimination half-life = time it takes for the concentration of the drug in the body to half Peak plasma levels = time it takes for the medication in the blood plasma to accumulate and reach peak concentration, the faster the absorption rate the lower the time to peak plasma concentration

Answer 9

As plasma clearance (ml/min/kg) decreases elimination half life increases Time to peak plasma levels increase Conc. of drugs with a long half life remains fairly stable

Answer 10

Felodipine = cleared faster, quicker accumulation of the medication in the blood plasma Amlodipine = cleared slower, effects last longer and more or less consistently, but takes longer to accumulate in the blood to cause the effects Amlodipine = more suitable = stays in the blood longer and more consistently throughout the day

Answer 11

Targets ACE - mainly in the lungs and some in the renal endothelium Stops conversion of angiotensin-1 to angiotensin-2 Angiotensin-2 is a very potent vasoconstrictor, so if this is inhibited, the peripheral vessels remain vasodilated Angiotensin-2 also induces aldosterone, which increases Na+ absorption resulting in increased H2O absorption, which increases blood volume. So lack of angiotensin-2 leads to increased urine output = lowered blood volume = lowered BP

Answer 12

Angiotensin receptor blockers - block the action of angiotensin-2

Answer 13

ACE = has functions other than converting angiotensin-1 to angiotensin-2, it also breaks down bradykinin, which accumulates and can lead to a cough ARBs block angiotensin-2 action directly, so ACE are still free to break down bradykinin

Answer 14

Afferent arteriole needs to be more open than the efferent arteriole to produce the pressure in the glomerulus that filters out the blood Lack of angiotensin-2 = lack of constricted efferent arteriole = lowered pressure = lowered eGFR Lack of angiotensin-2 = lack of aldosterone = more Na+ and water in the urine output = more K+ remains in the blood = hyperkalaemia. Increased K+ in the blood = can affect the heart

Answer 15

Block the sodium chloride co-transporter in the distal tubule More Na+ remains in the filtrate, which leads to increased water passed in the urine output For the first few weeks it leads to reduced cardiac output due to reduced venous return (due to lowered blood volume) But long term, reduces peripheral resistance

Answer 16

Earlier on in the distal tubule, the sodium chloride channel is blocked - preventing reabsorption of Na+ and Cl- But in the later part of the distal tubule, it is a different set of sodium transporters, which eliminate Na+ from the blood at the expense of K+ (As in K+ reabsorbed as Na+ excreted) This increases water reabsorption in the distal tubule Increased urine output Decreased cardiac output

Answer 17

After a while a mechanism adapts to overcome the reduction in cardiac output Cardiac output goes back to normal So in reality they work by decreasing total peripheral resistance

Answer 18

These drugs work in the kidneys, therefore must remain unchanged as they pass through the liver, when they reach the kidneys so they can have their therapeutic effect? (I think)

Pharmacology of Hypertension Flashcards

(42 cards)