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The Pharmacological Management of Hypertension. Altaz Dhanani Medicines Management Pharmacist, Supplementary Prescriber. What's Covered. Drug Treatment of Hypertension General points on treating Hypertension Questions???. Hypertension – Key Points. A modifiable risk factor - PowerPoint PPT Presentation
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Altaz DhananiMedicines Management Pharmacist, Supplementary Prescriber
Drug Treatment of Hypertension
General points on treating Hypertension
Questions???
A modifiable risk factor
Do not view in isolation
Don’t forget lifestyle advice
Intervention Avg reduction in SBP & DBP
% with 10mmHg reduction in SBP (<1 year)
Other Comments (from NICE 2006)
Diet (Healthy, Low calorie)
5-6mmHg ~40% Avg wt changes 2-9Kg
Exercise (Aerobic, 30-60mins, 3-5x/week)
2-3mmHg ~30%
Relaxation Therapy (Structured)
3-4mmHg ~33% Cost & availability to PCO unknown
Multiple Interventions
4-5mmHg ~25% Education alone unlikely to be effective
Alcohol Reduction 3-4mmHg ~30%
Salt Reduction (<6g/day)
2-3mmHg ~25% Effects diminish over time (2-3yrs)
Other: Caffeine (> 5cups/day inc BP by ~2-1mmHg, Smoking (per se) no effect on BP.
BP consistently ≥ 160/100
BP consistently ≥ 140/90 AND ◦ with existing CVD
or◦ target organ damage
or◦ raised CVD Risk of 20% or more
NICE 140/90
140/80 for type 2 diabetics
135/75 for type 2 diabetics with microalbuminuria or proteinuria
135/85 for type 1 diabetics (130/80 with nephropathy)
<55 years ≥55 years or BlackStep 1 A C or D
Step 2 A + C or A + D
Step 3 A + C + D
Step 4 A + C + D +
Further diuretic therapy or α-blocker or β-blockerConsider specialist advice
A=ACEi (ARB if intolerant), C= calcium channel blocker, D = thiazide diuretic
Ramipril, lisinopril, perindopril and others Works by manipulating the renin-angiotensin system Renin to angiotensin to angiotensin 2 via angiotensin
converting enzymes Angiotensin 2 = potent vasoconstrictor
Hence
ACEi’s inhibit the action of the angiotensin converting enzymes and prevent the conversion of angiotensin to angiotensin 2
Persistent dry cough Hyperkalaemia Worsening renal failure Angiodema Hypotension (1st dose) Rash, neutropenia....
Hypersensitivity to ACEi (incl. Angiodema)
Pregnancy
Renal insufficiency
Hyperkalaemia
K+ sparing diuretics and aldosterone antagonists (spironolactone) – severe hyperkalaemia
Lithium – lithium excretion ↓ Ciclosporin - ↑ risk of hyperkalaemia K+ salts - ↑ risk of severe hyperkalaemia
Generally recommended for people < 55 yrs and Caucasian
In diabetes, ACEi’s are an appropriate 1st line choice
Caution when initiating, 1st dose hypotension esp. with pts on concomitant diuretic therapy first dose at night
Monitor U&E’s before initiation and regular monitoring during treatment
Preferred Rx’ing drugs......
Losartan, Valsartan, Irbesartan etc Effects similar to ACEi’s Works by blocking angiotensin 2 (potent
vasoconstrictor) from entering receptors in the smooth muscles of blood vessels
Primarily SHOULD only be considered where an ACEi is indicated but not tolerated
Hyperkalaemia Angiodema Symptomatic hypotension – dizziness or
light-headedness
Contra-indicationsContra-indications PregnancyHepatic impairment for some agents
Much the same as the ACEi’s
Telmisartan ↑ plasma concentration of digoxin
SHOULD only used where an ACEi is indicated but not tolerated
NO compelling evidence to suggest they offer any clinical advantage over ACEi’s
No compelling evidence that there are differences between individual agents
Considerably more costly than ACEi’s Monitoring as per ACEi’s Preferred Rx’ing drugs.....
Amlodipine, Felodipine, Nifedipine etc Can be split into 2 groups dependant on
their properties:◦ Dihydropyridines (e.g. amlodipine)◦ Non-dihydropyridines (diltiazem, verapamil)
Dihydropyridines potent vaso-dilators, relax the vascular smoothe muscle and dilates the arteries
Flushing Headache Dizziness Ankle swelling
Theophylline - ↑ plasma conc of theophylline
Ciclosporin – plasma conc ↑ Digoxin – plasma conc ↑ Antifungals - ↑ plasma conc of
dihydropyridines Grapefruit Juice - ↑ plasma conc of
dihydropyridines (though not as significant an interaction as with simvastatin)
Equal 1st line choice with thiazide diuretics for pts ≥ 55yrs or pts who are of African or Caribbean descent
What about previous concerns over CCB’s re: that CCB’s increase risk of CV events independent of their BP lowering effect?
Immediate release formulations should be avoided (e.g. Non m/r nifedipine)
m/r formulations should be Rx’ed by brand name (nifedipine and diltiazem versions)
Bendroflumethiazide, Indapamide e.t.c. Stop the resorption of sodium hence
promoting its excretion leading to more urine being produced. Flushes excess fluids and minerals from the body
Act within 1-2 hours of administration and generally have a duration of action of 12-24 hours
Hypokalaemia Postural hypotension Impotence Mild GI effects
Cardiac glycosides – hypokalaemia caused by diuretics increases cardiac toxicity
Ciclosporin - ↑ risk of nephrotoxicity
Lithium - ↑ plasma conc.
Considered as equal first line choice with CCB’s for black pts or aged 55 yrs and over
Due to low acquisition costs of these drugs, may be used preferentially over CCB’s
Low doses of thiazides produce maximal or near-maximal BP lowering with little biochemical disturbance (higher doses confer little advantage in BP control but disturbs plasma concs of K+, Na+, uric acid, glucose and lipids!)
Atenolol, metoprolol e.t.c. Not exactly known how they work in
hypertension – but they ↓ cardiac output, and block the action of stress hormones that constrict the blood vessels in the heart, brain and body
Bradycardia Shortness of breath Coldness of extremities CNS effects with lipid soluble drugs
(propranolol) Impotence
Asthma/severe COPD Marked bradycardia Severe peripheral artery disease Heart Block
No longer recommended first line treatment BUT they are an option for:
◦ Younger patients with C/I’s for ACEi’s or ARB’s◦ Women of child bearing potential◦ Pts with compelling indications for their use (e.g.
ischaemic heart disease) Best avoided in combination with thiazide
diuretics
NICE If BP controlled....no absolute need to
replace the BB with an alternative If BP not controlled, revise treatment
according to treatment algorithm When a BB is withdrawn, step the dose
down gradually Do not withdraw if there are compelling
indications for being treated with one
NICE guidance on drug treatment NOT based on large clinical outcome studies – based on sound pathophysiological grounds and expert opinion
Do not forget lifestyle advice – to be offered on an ongoing basis
If drug intervention is needed, follow NICE algorithm unless there are compelling indications to do otherwise
Most patients will need more than 1 drug to control BP??
Β-Blockers do have a role in hypertensive therapy, but in limited circumstances
Remember treatment targets – but bear in mind it won’t be possible for all pts to achieve
Any lowering of BP is beneficial – esp. those at highest baseline CVD risk
Account for patients’ tolerability and concordance when reviewing treatment response
All patients should have at least an annual review of care
1. Does the pt really need drug therapy◦ Check your measuring technique◦ Measure several readings over a period of time◦ Review all potential drug causes and try non-drug therapies
first (unless BP really high)◦ Attend to other risk factors – smoking, lipids etc
2. If treatment is necessary, getting the pressure down is more important than worrying too much about which drug to use
◦ Thiazides are first choice for most people, CCB’s probably less so, doxazosin (α-blocker) first choice for almost no one!
3. Treat the patient, not the blood pressure◦ A drug that is not taken will not work and is the most
expensive medication◦ Potential benefits of aggressive therapy with multiple drugs
must be weighed against the acceptability to the patient of such therapy