Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

PH2501- pharmacology > Lec 18- HTN > Flashcards

Lec 18- HTN Flashcards

1
Q

Definition of HTN

A
  • An elevation of arterial BP above normal
  • Normally dependant on total peripheral resistance
  • Linked to increase risk of CVS disease and mortality
  • Definitions are based upon CVS risk- BP is normally distributed variable
  • A sign, not a disease state
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is normal BP

A
  • High 140+/90
  • Pre-high 120-140/80-90
  • Ideal 90-120/60-80
  • Low <90/<60
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Classification of hypertension

A
  • Primary HTN (essential) - unknown Aetiology
  • Secondary HTN (Non-essential) known aetiology
  • Renal HTN
  • Endocrine HTN
  • Hypertension of pregnancy
  • Latrogenic hypertension (caused drug induced)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Signs and symptoms

A
  • Generally no signs or symptoms of HTN
  • Can be difficult therefore patients to adhere or want to take there medication
  • In extreme cases (180/90 +): severe headache; fatigue; vision problems; arrhythmias; pounding sensations; pain discomfort; blood in urine
  • If left untreated may present with: organ damage; stroke; AMI: HF; dementia or peripheral arterial disease
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Risk factors for essential HTN

A 
NON-MODIFIABLE 
-Age 
-Race
-Gender
-Family history 
MODIFIABLE
-Sedentary lifestyle 
-Poor diet 
-High Na 
-Obesity 
-High alcohol consumption
-Smoking
-Stress
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Objectives of therapy

A
  • Not to just reduce BP- to reduce CVS outcomes of HTN
  • BP not only factor in deciding therapy
  • Outcome data is essential
  • Risk/benefit analysis is critical
  • Need to achieve long term, 24 hour reduction in BP, monitoring critical
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Holistic measures

A
  • Maintain normal weight for adults
  • Reduce salt intake <100mmol/day
  • Limit alcohol intake <3 units for men <2 for women dd
  • Engage in regular aerobic physical exercise for >30 min dd
  • Consume at least 5 fruit and veg dd
  • Reduce the intake of total and saturated fats
  • Reduce stress
  • Stop smoking
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Risk assessment

A

Assessing organ damage

  • Urine dip for protein&blood
  • ACR (albumin to creatinine ratio)
  • Bloods for U&E’s; ChE and lipid profile
  • Optometrist: fundoscopy to view retina for damage
  • 12 lead ECG
  • QRISK 3 score for 10yr CVD risk assessment
  • More detail required if: HIV: autoimmune disease; family hypercholesterolaemia; U40 with stage 1 HTN
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Thresholds for diagnosis and treatment of HTN

A
  • Stage 1 HTN –> target organ damage; CVD or 10 yr CVD risk >20% if yes then treat/ if NO then lifestyle advice then review in 1 year
  • Stage 2= treat
  • Severe hypertension >180/110 must treat immediately don’t wait for ABPM
  • Accelerated HTN >180/110 + retinal haemorrhage or papilloedema- must refer to specialist
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

BP treatment target

A
  • Use clinical BP to monitor BP control
  • Optimal clinical BP control is <140/90 mmHg
  • In people with white coat effect- can be 20/10 more than home average so use a home monitor- target home <135/85
  • Review BP control at least annually once BP treatment is stable
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Ideal antihypertensive

A
  • Slow, controllable onset of action
  • Sustained control- supine and standing
  • 12-24hr duration of action- compliance
  • Orally active (for long term therapy)
  • No -ve inotropic action/reflex bradycardia
  • No adverse reactions suitable for long term
  • No development of tolerance
  • Beneficial effects on morbidity and mortality
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Ideal antihypertensive

A
  • Slow, controllable onset of action
  • Sustained control- supine and standing
  • 12-24hr duration of action- compliance
  • Orally active (for long term therapy)
  • No -ve inotropic action/reflex bradycardia
  • No adverse reactions suitable for long term
  • No development of tolerance
  • Beneficial effects on morbidity and mortality
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

NICE GUIDELINES- HTN

A 
AGED <55 yrs 
1) ACEI 
2) ACEI + CCB 
3)ACEI + CCB + thiazide 
4)ACEI + CCB + thiazide + further diuretic advice 
AGED <55 
1) CCB
2)CCB+ ACEI 
3) CCB + ACEI+ thiazide
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Resistance HTN- step 4

A
  • A clinical BP that remains higher than 140/90 mmHg with the optimal or best tolerated doses of a drug from group A,C and D
  • Expert advice may be needed and further review to exclude endocrine and other causes of HTN
  • After this agents used may be from other such as: BB; Alpha blocker; Spspironolactone; vasodilator
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

ACEI in HTN (group A)

A

Haemodynamically arterial vasodilators
-All agents are equally effective
-decreased BP doesn’t correlate with changes in plasma renin or all some effect in anaphoric individuals
Best haemeodynamic profile
-Increase in renal blood flow
-Cerebral and coronary flow well maintained. Improve arterial compliance (SBP)
-Aldersterone release well controlled

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

ACEI- advantages

A

Effective- equal reduction DBP to all other anti-HTN greater effect on SBP

  • Generally well tolerated, high acceptability: no adverse metabolic effects
  • Raggression of LV hypertrophy and of vascular remodelling: highly beneficial in LV systolic dysfunction- use in all HTN with LVSD even if asymptomatic
  • Retard progression of diabetic nephropathy: use in all patients with nephropathy, all diabetic
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

ACEI- diadvantages

A

-Deterioration of renal function in renal stenosis
Bilateral and unilateral one kidney. May be exacerbated by NSAID’s
-ACE is not selective for angiotensin formation; reduced metabolism of kinins and neuropeptides: skin rash; dry cough; angioneurotic oedema
-Foetopathic potential
-Hyperkaleamia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Angiotensin receptor blockers ARB’s

A
  • Competitive antagonists at AT1 receptors
  • More precise pharmacological control of RAS
  • Highly selective- no effect on kinins on SNS
  • Well tolerated: slow onset of action with minimal first dose effect
  • Do not produce cough associated with ACEI
  • Otherwise similar to ACEI: don’t use in pregnancy; in renal failure; if there is renal artery stenosis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Renin antagonist

A
  • Directly inhibits renin
  • Essential HTN
  • Similar side-effect profile as ACEI/ang ||
  • Not recommended for use with ACEI/Ang||
  • ALTITUTE study found adverse CV and renal events when used in combination with ACEI/Ang||
  • In practice rarely used-very select patient under specialist advice
  • Not for use with P-gp inhibitors
  • Interactions with grapefruit juice
  • No fruit juices to be taken at the same time
  • Used as a reserve agent when other fail to achieve control
20
Q

Calcium entry blockers

A
  • CEBs are one of a group of vasodilators
  • Block voltage gated Ca2+ channel
  • Main group differ in vascular selectivity- verapamil- dihydopyridines are most widely used to reduce TPR
  • Direct action on VSM to reduce TPR
  • Effect action of all vasoconstriction- not receptor antagonists (distal action)
  • Action independent of sympathetic tone
  • Good haemaerodynamic profile- Increase RBF and maintain or improve renal function, maintain cerebral and coronary flow
21
Q

CEB

A

-Effective anti-hypertensive- used for chronic control but also may be used for rapid reduction in BP (acute control) e.g. HTN emergency or surgical control of BP

22
Q

The Dihydropyridines

A
  • Nifedepine- rapid action, starts in 20 mins with half-life of 3 hours. MR/SR preps
  • Amlodipine- slow onset, half life 35-48 hrs. OD
  • Nicardipine and felodipine most vascular selective
  • Nimodipine- mainly used for sub-arachnoid haemorrhage
23
Q

Advantages of Dihydropyridines

A
  • Effective- comparable with other major agents
  • May be used in: Asthma + COPD; peripheral vascular disease; gout; diabetes
  • Positively indicated in: cerebrovascular disease; peripheral vascular disease
24
Q

Disadvantages of Dihydropyridines

A
  • Number of side effects due to vasodilation: facial flushing; headache; nausea; ankle oedema
  • Myocardial depression with verapamil
  • Coronary Ischemia with short-acting DHPs
25
Q

Diuretics in HTN

A

Thiazides most widely used

  • Alone will control BP in about 50% of all ESH’s. Adding other diuretics doesn’t improve efficacy
  • A flat DRC with maximum AH effect around 2.5mg bendrofluazide. Linked to diuresis (no effect anaphoric dependant on Na+ intake) but different DR releationship
  • Loop diuretics- torasemide only loop diuretic licensed for hypertension when renal function is poor (GFR<60% normal, serum creatinine >150
26
Q

Diuretic mechanism of action

A
  • Onset of anti-HTN slow- Mac at around 12 weeks. Early fall in CO and extracellular volume (10%)
  • At peak anti-HTN action, fall in TPR. Attributed to auto regulation of tissue blood flow (normalises CO and tissue blood flow)
  • Anti-HTN action reduced NSAID
  • Undesirable effects- minimised by low dose: Decresase K/Na/Mg/Ca, glucose intolerance; hyperuricaemia and hyperlipoproteinaemia
27
Q

Diuretic risk profile +ve indications and general advantages

A 
\+ve indications
-Old age- strong evidence 
-Congestive HF 
-For loop (thiazide add on therapy) 
General Advantages 
-Cheap 
-Widely effective 
-Generally well tolerated 
-Substantial evidence base
28
Q

Diuretic Risk Profile -VE INDICIATIONS

A
  • Diabetes
  • Gout
  • Obesity
  • Hyperlipdaemia
  • Where hypokalaemia may be a problem e.g. cardiac dysrhythmias
29
Q

Choice of diuretic

A
  • Chlortalidone (12.5-25mg OD) or indapamide in preference to bendroflumethazide
  • Evidence review found no evidence in clinical outcome trials of benefits with bendroflumethazide
  • Most recent trials showing benefit with lower dose diuretics have used thiazide-like diuretic e.g. indapamide
  • No need to change diuretic in people stable on treatment and in whom BP is controlled
30
Q

Anti-sympathetic Drugs

A
  • Autonomic ganglion Blocking agent
  • Adrenergic neurone blocking agent
  • a1- adrenoreceptor antagonist e.g. prazosin; doxazosin; terazosin
  • B-adrenoceptor antagonists - propranolol (B1 and B2), atenolol (B1 selective)
  • Centrally acting a2-agonists e.g. clonidine, methyldopa and monoxide
31
Q

B-adrenoceptors antagonists (group B)

A
  • Not designed an anti-HTN- action recognised in clinical trials for angina
  • Anti-HTN action associated with action at B1-adrenoceptors
  • Many of the undesirable actions are linked to effect at B2-adrenoceptors: bronchoconstriction- pulmonary B2 receptors; Hypoglycaemia- B2 hepatic glycogenolysis
32
Q

B-adrenoceptor antagonists

A

Consider for younger people particularly

  • Women of child bearing age
  • Where there is evidence of increased sympathetic drive
  • Where intolerance to ACEI or ARB|| Antagonists
  • May be compelling reason to use e.g. angina
  • No reason to withdraw where BP controlle , if withdrawing do so slowly
33
Q

Mode of action in HTN

A
  • Reduction of CO: acute- may precede anti-HTN action; general effect all agents
  • Suppression of renin release : very rapid does’t correlate well with decreased BP
  • Central inhibitory action on sympathetic outflow
  • Action on peripheral nerves- blockade of pre-synaptic B-receptors
34
Q

B-antagonists disadvantages

A
  • Recent trials: less effective at reducing major CVS outcomes, particularly stroke
  • Reduce cardiac sympathetic: care in failure/disease; CI conductivity defects
  • Unfavourable on blood lipids and blood glucose. care hyperlipidaemia
  • CNS disturbances- linked to lipophilicity
  • Impotence in males
  • Effects on B2 receptors: care asthma/COPD; care PVD
35
Q

B-antagoinsts advantages

A
  • Cheap
  • Effective in high output HTN e.g. labile
  • Effective in young ESH
  • Good in co-existing angina without cardiac failure
  • 12/24 hr dosing easy
  • Good high renin ESH
  • Side effects- bradycardia, cold
36
Q

a1-adrenoceptors antagonist e.g. doxazosin- advantages

A
  • Well tolerated
  • Few metabolic effect: favourable on blood lipids; no effect on glucose tolerance
  • No bronchospasm
  • +ve indications: PVD; diabetes; elderly males in prostatic hypertrophy
37
Q

a1-adrenoceptor antagonist- disadvantages

A
  • First dose effect- may see precipitate fall in BP (worst prazosin)
  • Vasodilator side effects e.g. flushing
  • Less effect upon CVS events particularly HF (ALLHAT study)
38
Q

Centrally active a2- agonist e.g. clonidine and methyldopa- advantages

A
  • Good BP control
  • No postural hypotension
  • a-methyldopa is well established. useful in pregnancy
  • No effect bronchial smooth muscle (asthma)
  • No direct cardiac action
39
Q

Centrally active a2- agonist e.g. clonidine and methyldopa- disadvantages

A
  • Rebound HTN
  • Dry mouth
  • Constipation
  • Impotence in males
  • Tolerance may occur
  • a-methyldopa only: sedation; blood dyscarsias; hypersensitivity
40
Q

Other direct vasodilators

A

Sodium Nitroprusside
-Active only by IV infusion
-Very short duration of action
-Highly effective for short term use
-Toxicity- thiocyanate (chronic); cyanide (acute)- dangerous
Diazoxide (k channel activator)
-Chemically related to thiazide diuretics
-Major action on arteriolar muscle
-Can be used IV (emergency) and active orally
-Problems: hyperglycaemia; volume expansion; decrease K
-Main use: emergency treatment of increased intra-ocular pressure

41
Q

Other direct vasodilator advantages

A
  • Direct reduce TPR. Potent anti-HTN
  • Good side effect profile: no -ve isotropy; favourable on blood lipids
  • A number of specific uses e.g. HTN crisis
42
Q

Other Direct vasodilators disadvantages

A
  • Can produce precipitate fall in BP
  • Activation of baroreceptor reflex producing reflex tachycardia and increased plasma renin activity
  • Na+ and H20 retention 2ndary to inc. plasma renin activity
  • Care in IHD- may precipitate angina- avoid after AMI
  • Range of drug specific side-effects and contra-indications
43
Q

Renovascular HTN

A
  • Reduction of blood supply to one or both kidneys
  • A number of causes of reduced flow: stenosis (fibromuscular dysplasia); 2ndary to atherosclerosis; obstruction due to tutors, thrombosis etc
  • One kidney “vasoconstriction driven’ (activation of RAAS)
  • 2 kidney- volume expansion
44
Q

Endocrine HTN

A

Normally due to problems with pituitary or adrenal glands (to much cortisol)

  • Phaeochromocytoma (rare tutor of adrenal gland, excess NA)
  • Cushings: 2ndary or primary (benign tumor pituitary gland; excess ACTH; resulting in excess aldosterone); HTN in 75%; volume loaded HTN
  • Conns syndrome; adrenal adenoma with aldersterone release
  • Hyperthyroidism: classical high output HTN
45
Q

HTN in pregnancy

A
  • Chronic HTN: antedates pregnancy but may be exacerbated. 30-50% of all cases
  • Gestational HTN (PIH): Normotensive individual before pregnancy. BP at least on 2 occasions 6hrs apart
46
Q

HTN in pregnancy- in pre-eclampsia/eclampsia

A
  • Pre-eclampsia: with proteinuria and oedema
  • Eclampsia (toxaemia of pregnancy) extensive intravascular clotting; convulsion; hepatic and renal dysfunction
  • 65% in primagravidas. 5-10% all pregnancies
  • Risks:>40 years age, previous history; DBP >80 at start
47
Q

Drug treatment of PE/PIH

A

-Challange
-No proven benefit 110, SBP >170 mmHg
Therapy: ACEI and ARB|| antagonists contra-indicated; diuretics undesirable
Early pregnancy: methyldopa; Beta-blocker- labetalol; CEB- nifedipine
Late pregnancy: methyldopa; CEB- nifedipine slow release

PH2501- pharmacology (47 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions