Transcript Case study 1 - C109’s Blog

Hypertension
Therapeutics Lecture
Semester 6
Lesson Outcomes:
Therapeutics of Hypertension
Semester 6
Contents
IMU Domain
Review of the cardiovascular risk factors
Non-pharmacological measures to reduce blood pressure
The common classes of anti-hypertensive drugs
Adverse effects of anti-hypertensive drugs
Selecting an anti-hypertensive drug
Influence of co-morbid factors in drug selection
Monitoring drug therapy
Resistant hypertension
Hypertensive urgencies/emergencies
Hypertension and pregnancy
1,4
1,2
1
1
1,2,7
2,7
2,7
1,2
1,2
1,2
(Not covered: Detection and evaluation of hypertension)
Case Study 1
Mr. C, a 64-year-old ex-banker, is found on routine medical check up to have a
BP of 170/100.
He is asymptomatic and is usually in good health. He does not smoke and stopped
drinking alcohol 4 years ago. There is no known family history of hypertension but his
father died in his 50’s possibly from acute MI.
On examination:
BMI 27. BP 170/90. Otherwise physical examination is unremarkable.
Investigation:
Total cholesterol: 6.5 mmol/L, LDL 4.8 mmol/L, HDL 1.3mmol/L.
ECG: sinus rhythm with no signs of LVH.
How would you advice him?
Non-Pharmacological measures to reduce BP
Weight Reduction: BMI < 23
Sodium Intake (< 100 mEq/L of Na or 6g NaCl a day)
Diet Plan
Physical Exercise (aerobic exercise ≥ 30 minutes ≥ 3 times/wk)
Avoid/Reduce Alcohol (<21 units/wk ♂ ; < 14 units/wk ♀: 1 unit = 9 g of alcohol)
Stop Smoking
Case Study 1
Mr. C’s BP is found on follow-up to be persistently in the range of 160-170/90-100.
He is diagnosed to have hypertension.
Before commencing drug treatment what else would you discuss with the patient?
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Explain the diagnosis
Explain risk of not treating
Explain need for long-term treatment
Discuss medication to be used and possible side-effects
Inform need for regular follow-up
Ensure continuation of non-pharmacological measures
Case Study 1
Mr. C was started on a thiazide diuretic (other drug choices also possible)
Thiazide Diuretics (eg. hydrochlorothiazide, chlorothiazide)
What are the possible side-effects of thiazide diuretics?
Hypokalaemia
Hyperuricaemia ( can precipitate gout)
Hyperglycaemia (can worsen diabetes in high doses)
Hyponatremia
Alkalosis
Monitor renal profile
Monitor diabetes
Case study 1
After one month Mr. C is reviewed in the clinic. His BP is 160/90.
Renal profile and serum uric acid are normal.
It is decided to add a second drug to his treatment regimen.
An angiotensin-converting enzyme inhibitor (ACEI) is added
What are the possible side-effects of ACEIs?
Dry cough
Hyperkalaemia (care with K supplements, spironolactone)
Worsen/precipitate renal failure (contraindicated in bilateral renal artery stenosis)
First dose hypotension (care in dehydrated patients)
Allergic rashes
Angioedema
Contraindicated in pregnancy
Monitor renal function
Case Study 1
Mr. C develops cough with the ACE Inhibitor and is changed to an angiotensin-receptor
blocker (ARB)
What are the possible side-effects of ARBs?
Hyperkalaemia
Renal impairment
Hyponatremia
Hypotension
Contraindicated in pregnancy
Monitor renal function
Avoid in bilateral renal artery stenosis
Case Study 1
If Mr. C’s blood pressure is still not controlled what would you do?
1. Check adherence to medication
2. Check if carrying out non-pharmacological measures
3. Check if there are any drug interactions: alcohol, NSAIDS
4. Recheck for causes of secondary hypertension
If Mr. C requires a third drug to achieve target BP what would you add?
A calcium channel blocker (CCB) is used.
Possible side-effects:
Headaches, dizziness, flushing
Oedema
Constipation
(Short-acting CCBs should be avoided because of the higher risk of adverse cardiac
events; long-acting or sustained release preparations preferred)
Case Study 2
A 43-year-old woman with diabetes for 10 years and hypertension for 5 years is seen in
the MOPD for follow-up.
Her current medication is metformin 500 mg tds, gliclazide 80 mg od, simvastatin 40 mg
on, hydrochlorothiazide 12.5 mg od, telmisartan 80 mg od and amlodipine 5 mg od.
Her BP is 150/90 and the medical officer decides to add metoprolol 50 mg bd.
Questions for discussion:
Can thiazide diuretics be used in diabetic patients?
Can beta-blockers be used in diabetics?
Case Study 2
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Thiazide diuretics may worsen diabetes by causing hyperglycaemia.
However in clinical trials, there is no difference in cardiovascular outcomes between
different anti-hypertensive drugs as long as BP control is achieved.
Many guidelines recommend that in diabetics, diuretics may be added to the antihypertensive regime to achieve target BP1,2.
Low doses recommended.
RAS blockers is the first-line treatment unless contraindicated.
1. ASH Position Paper: Treatment of Hypertension in Patients with Diabetes.
The Journal of Clinical Hypertension 2008; 10: (issue 9) 707-713
2.The JNC 7 Report. JAMA. 2003; 289: 2560-2571
Case Study 2
Beta-blockers in uncomplicated hypertension:
 In hypertensive patients without diabetes, starting β-blockers (especially if combined
with diuretics) results in a higher incidence of new-onset diabetes1.
 β-blockers are not recommended as first-line treatment of hypertension unless there
is a compelling indication2.
In diabetes with hypertension:
 Cardiovascular outcomes are improved by achieving target BP.
 β-blockers can be added on to the treatment regime to achieve target BP3,4.
 Newer generation β-blockers (those with ‘vasodilating’ effects: carvedilol) preferred
over older β-blockers (atenolol, metoprolol)
1. Diabetes Care. 2006; 29(5);1167-1169.
2. NICE clinical guideline 34. Hypertension: management of hypertension in adults in primary care. June 2006.
3. The JNC 7 Report. JAMA. 2003; 289: 2560-2571.
4. The Journal of Clinical Hypertension. 2008; 10: (issue 9) 707-713.
Case Study 2
Possible side-effects if a β-blocker is used:
Fatigue
Bradycardia, heart block
Bronchospasm (avoid in asthma)
Impotence in males
Metabolic:
Hyperglycaemia
Adverse lipid profile changes (↑TG ↓HDL-C)
May mask symptoms of hypoglycaemia/hyperthyroidism
β-blockers should not be stopped suddenly; tail off over 1-2 weeks
Choice of drug treatment
There is no ‘fixed rule’ as to which drug to start a particular patient on
Choice is best ‘individualized’ based on:
Type and severity of hypertension
Age
Presence of co-morbid medical conditions
Cost/economics
Ethnicity (more research needed)
Initial Treatment of Hypertension
(without other co-morbid risk factors)
Younger than 55
55 Years Or Older
A
C or D
A+C
or
A
+ C + D
A = ACE Inhibitor (or ARB)
C = Calcium-Channel Blocker
D = Thiazide-Type Diuretic
British Hypertension Society / NICE clinical guideline 34 (2006)
A+D
Co-morbid Conditions and Choice of Drugs in Hypertension
Diabetes/Chronic Renal
Disease
ACEIs or ARBs
Stroke
ACEIs ± Diuretics
IHD/Angina
β-blockers
CCBs (long-acting)
Post-AMI/Heart Failure
β-blockers and ACEIs
Elderly/Isolated Systolic
Hypertension
Diuretics or CCBs
The JNC 7 Report. JAMA. 2003; 289: 2560-2571
Starting hypertension treatment
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Drug therapy is often initiated with a single drug at a low dose.
Monitor for response and side-effects.
Monotherapy lowers BP to target levels in only about half of patients with mild to
moderate hypertension.
If target BP is not achieved it may be preferable to add a second drug from another
class rather than to keep increasing the dose of the first.
For those with moderate/severe hypertension (BP > 160/100) consider starting with a
2 drug combination.
Diabetics often require more than one drug and often up to 3 or 4 to achieve target
BP levels.
Clinical Practice Guidelines: Management of Hypertension (3rd Edition) 2008
Academy of Medicine Malaysia
Targets
Patient Group
Target BP
Most Patients
BP < 140/85
Diabetics
BP <130/80
(Proteinuria >1g/day BP
<125/75)
Clinical Practice Guidelines: Management of Hypertension (3rd Edition) 2008
Academy of Medicine Malaysia
Resistant Hypertension
Consider :
• Compliance
• Drug Interactions/Excessive Sodium Intake/Alcohol
• Renovascular Disease
• Secondary Hypertension
Hypertensive Urgencies and Emergencies
Usually BP > 220/120
Urgencies
• Asymptomatic or symptomatic
• Usually admit: oral treatment
Emergencies:
(acute LVF, dissecting aortic aneurysm, hypertensive encephalopathy,
acute renal failure)
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Admit
IV treatment: labetalol, nitrates, hydrallazine, sodium nitroprusside
Hypertension and Pregnancy
Differentiate between:
1. Pregnancy-induced hypertension / pre-eclampsia.
2. Pre-existing / chronic hypertension (hypertension that is present before pregnancy or
diagnosed before 20th week of gestation or first diagnosed in pregnancy and persists
beyond D42 post-partum).
Suitable drugs:
• α-Methyldopa
• Labetalol
• Nifedipine
(ACEIs are contraindicated because of foetal abnormalities and death)
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For pregnancy-induced hypertension, long term follow up is advised
because of the higher likelihood of developing hypertension.
For pre-existing hypertension, pregnancy is best planned and BP well controlled before
conceiving.
“The most effective treatment prescribed by the most careful clinician will
control hypertension only if the patients are motivated. Motivation improves
when patients have positive experiences with, and trust in, the clinician. “
JNC VII 2003
End of lecture
Thank you