Transcript RELIEVING THE PRESSURE

Medications for Treating Hypertension
Jeannie Collins Beaudin, RPh
Keswick Pharmacy
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WIDESPREAD PROBLEM...
CANADIAN STATISTICS:
 More than 1 in 5 adults have hypertension (22%)
 46% of Canadians age 55-65
 42% - No diagnosis
 Only 16% are controlled
 9% of those with diabetes (more stringent targets)
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IMPORTANCE OF NURSES’ ROLE
 Nurses have:
 Frequent patient contact
 Patient trust
 Favourable financial model

Educational role
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...PART OF THE PICTURE
 METABOLIC SYNDROME:
 Hypertension
 Insulin resistance
 Hypercholesterolemia
 Abdominal weight gain
 Prothrombic state
 Pro-Inflammatory state
 All are risk factors for cardiovascular disease
 #1 cause of death
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CAUSES OF METABOLIC SYNDROME
 Obesity
 Inactivity
 Poor diet
 Unknown genetic factors
 Stress?
 Cortisol


Increases BP, heart rate, lipids, blood glucose
Weight gain around waist
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KEY CHEP MESSAGES...
 Need to assess overall CVD risk
 Combination of drug therapy and lifestyle changes are
most effective
 Monitor regularly when above target
 Regular screening for all adults
 Focus on adherence
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ADHERENCE
 Assess regularly


Encourage patients to bring bottles
Check date filled and amount remaining
 Fit to daily schedule
 Strive for once daily dosing
 Long-acting formulas
 Fixed-dose combinations
 Fewer pills per day
 Often more expensive, not covered
 Use unit-of-dose packaging
 Improve patient education
 Encourage patient involvement in monitoring
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TYPES OF HYPERTENSION
MEDICATIONS
 Those that affect hormone systems
 Beta-blockers
 ACE Inhibitors (angiotensin converting enzyme
inhibitors)
 ARBs (angiotensin receptor blockers
 Those that affect electrolytes
 Fluid balance

Diuretics
 Vasodilation

Calcium channel blockers
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ABCs OF HYPERTENSION MEDS
A. Angiotensin Converting Enzyme Inhibitors (ACE-I),
B.
C.
D.
E.
Angiotensin Receptor Blockers (ARB)
Beta-Blockers
Calcium channel blockers (CCBs)
Diuretics
“Everything else”... Alpha-Blockers
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ACE-Inhibitors
 End with “-pril”
 Block the enzyme that converts Angiotensin I to
Angiotensin II
 Also reduce morbidity/mortality of
 HF, angina, stroke, DM neuropathy
 Generally well tolerated
 25% can develop dry cough

ACE enzyme also block breakdown of bradykinin (xs causes
cough)
 Teratogenic – caution in pre-menopausal women
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ANGIOTENSIN RECEPTOR
BLOCKERS (ARBs)
 End with “-sartan”
 Block the effect of Angiotensin II instead of blocking
production
 Actions similar to ACE-I
 But does not affect bradykinin
 No cough side effect
 Better tolerated
 More expensive
 Also teratogenic
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BETA-BLOCKERS
 End with “-olol”
 “Beta adrenergic receptor blockade”
 Block beta receptors for adrenalin
 Beta-1, Beta-2 receptors
 Beta-1 - heart, blood vessels

Beta-1 selective BB’s (e.g. Atenolol, Metoprolol)
 Beta-2 - lungs, brain

Non-selective BB’s (e.g. Propranolol, Nadolol)
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BETA-BLOCKERS
BETA-2:
 Lungs
 Bronchodilation

Site of action of Salbutamol (beta-agonist)
 Brain
 Dreaming
 Migraine

Beta-blockers can decrease frequency
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BETA-BLOCKERS
 Block action of adrenalin and beta(adrenalin) agonists
on lungs:
 Can worsen bronchospasm, asthma
 Block action of inhaled Salbutamol
 Can be useful for blocking essential tremor
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BETA-BLOCKERS
 Disadvantages:
 Slow heart rate, lower blood pressure (fatigue)
 Reduce blood flow to extremities (cold hands, feet,
impotence)
 Less heart-selective can increase dreaming
 Increase risk of diabetes (especially with diuretics)
 Not recommended over 65 years
 Advantages:
 Reduce mortality post-MI
 Also useful for HF, angina
 Non-cardio selective can prevent migraine
 Inexpensive
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CALCIUM CHANNEL BLOCKERS
 Calcium is necessary for smooth muscle contraction
 Calcium enters cells via tiny channels
 Blocking calcium channel inhibit muscle contraction


Vasodilation
Reduced force of heart muscle contraction
 Affect heart, blood vessels – not skeletal muscle
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CALCIUM CHANNEL BLOCKERS
Three types:
 Dihydropyridines (DRPs) - end with “-dipine”

Amlodipine, Felodipine, Nifedipine
 Phenylalkylamines

Verapamil
 Benzothiazepines

Diltiazem
 Last 2 have similar characteristics

Often referred to as “non-dihydropyridines” (non-DRPs)
 Essentially 2 classes now: DRPs and non-DRPs
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CALCIUM CHANNEL BLOCKERS
DIFFERENT SITES OF ACTION:
 DRPs (-dipines) act mainly on blood vessels “vasodilating”


Excess relaxation -> peripheral edema
Adversely affect renal function in diabetes
 Non-DRPs (verapamil, diltiazem) also act on heart
“modulating”





Verapamil has the strongest effect on heart
Diltiazem is “middle of the road”
Both slow conduction of impulse through AV node
 Caution with 2nd and 3rd degree heart block
Avoid in heart failure
Renal protective
 Preferable if risk of diabetes or kidney damage
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CALCIUM CHANNEL BLOCKERS
 No effect on:
 Insulin secretion or action
 Blood glucose
 Plasma protein levels
 Potassium balance
 Magnesium balance
 Grapefruit interaction
 Amlodipine, felodipine
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CALCIUM CHANNEL BLOCKERS
 Short-acting nifedipine
 Spike in norepinephrine, transient rise in plasma renin


Reflex tachycardia, BP rise
No longer used for emergency hypertension
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DIURETICS
 End with “-ide”
 Hydrochlorothiazide, indapamide, furosemide
 Act on kidney to increase fluid excretion
 Reduced blood volume -> reduced pressure


Thiazides – act on tubules
Furosemide - “Loop” diuretic, more potent
 Most cause loss of potassium
 Increased risk of electrolyte imbalances
 Exceptions “potassium sparing”:
 Spironolactone (Aldactone)
 Amiloride (in Moduret, Apo-Amilzide),
 Triamterene (in Dyazide, Apo-Triazide, Nov0-Triamzide )
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DIURETICS
 Many side effects:
 Lethargy, reduced exercise tolerance, polyuria
 Hypokalemia


Skeletal muscle weakness, GI hypomotility (ileus,
constipation)
Leg cramps, arrhythmia
 Can precipitate gouty arthritis (increased uric acid)
 Adverse effect on glucose and lipids (especially with B-
Blockers)

Poorer compliance noted than with other classes
 Very inexpensive, effective
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“EVERYTHING ELSE”
ALPHA BLOCKERS
 End with “-azosin”
 Prazosin, terazosin
 Also used for enlarged prostate
 Block alpha adrenalin receptors
 Strong rapid blood pressure reduction
 Dose must be started low and raised slowly
 Side effect:
 Postural hypotension (may be severe)
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CONCLUSION...
 HTN is most important cause of stroke, angina and
renal and heart failure
 Most important key for successful treatment is patient
education
 Important to focus on multiple CV risk factors:
 10%  in BP + 10%  in TC = 45%  in CVD!
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THANK YOU!
QUESTIONS?
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