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CLINICAL
The April issue of the South African Medical Journal contains the new guidelines for the prevention, diagnosis and
treatment of hypertension in South Africa. 1 These guidelines are very comprehensive and give practical advice
on lifestyle changes, risk stratification and treatment options. These guidelines are available at
www.hypertension.org.za. All healthcare workers in South Africa should adhere to these guidelines to standardise
the approach to every hypertensive patient. This article summarises some of the highlights and doesn’t replace
the original text.
Latest South Africa
HYPERTENSION GUIDELINES
released
Blood pressure measurement
Cardiovascular risk stratification
Standardising blood pressure measurement is
clearly outlined in this guideline. Of utmost
importance are the recommendations for
validated blood pressure devices. Only upperarm devices are recommended and
pharmacists should only stock devices that are
validated by the SA Hypertension Society. A
comprehensive list of validated devices is
available at www.dableducational.com. SAPJ
will soon publish a comprehensive list of
validated devices that are available in South
AFrica. Moreover, pharmacists should check
the devices in their clinics, have them
calibrated and communicate new guidelines to
clinic sisters.
Implementing lifestyle changes will not only
reduce the risk of developing hypertension and
reduce blood pressure levels, but will also
reduce the risk of developing any other cardiovascular diseases. Patients may already have
some major risk factors (abdominal obesity,
dyslipidaemia, type 2 diabetes mellitus, family
history of early cardiovascular disease and
smoking). Four factors are taken into
consideration when classifying a patient into a
specific risk category namely, blood pressure
levels, the presence of 1-2 or >3 major risk
factors, the presence of target organ damage
and/or diabetes mellitus, and the presence of
other associated clinical conditions (heart
failure, coronary heart disease, stroke or
transient ischaemic attacks, peripheral artery
disease and retinopathy).
Lifestyle changes
No longer should hypertension be monitored
with a blood pressure reading only. Adequate
monitoring of hypertensive patients includes
adherence to lifestyle modifications and
compliance with drug regimens. The guidelines give practical advice on these lifestyle
modifications. The key message is that lifestyle
changes can lower blood pressure, prevent
hypertension as well as other cardiovascular
diseases. The lifestyle modifications include
weight reduction, restriction of daily alcohol
and sodium consumption, adherance to a
specific diet plan (reduced fat intake and
increased intake of fruits, vegetables and
wholegrain foods), physical exercise and
smoking cessation.
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The five risk categories are: average risk, low
added risk, moderate added risk, high added
risk and very high added risk. Most patients
with low and moderate added risk can be
managed at primary healthcare level and
should be seen every 6 months.
Additional investigations
The following investigations should be
performed at the first visit and should be
repeated yearly if normal: urine dipsticks,
microalbuminuria, blood glucose and random
total cholesterol. The following should be done
at every visit: average blood pressure (of two
SA Pharmaceutical Journal – May 2006
CLINICAL
readings), weight and BMI and waist
circumference. Patients should be
referred to the general practitioner for
the following yearly tests: blood
(creatinine and potassium levels) and a
resting ECG to detect left ventricular
hypertrophy.
•
Treatment
Patients are managed according to the
specific risk categories. The targets for
blood pressure on lifestyle modification
and drug treatment are <140/90 mmHg
for all stages of hypertension and
<130/80 mmHg for high-risk patients
(those with diabetes and renal disease
and congestive heart failure).
Drug treatment should be commenced
in the following cases:
• Low added risk despite a period of
6-12 months of lifestyle modifications and observation.
• Moderate added risk despite a
period of 3-6 months of lifestyle
modifications and observation.
• High or very high added risk.
Drug choices
• Uncomplicated hypertension cases
are now treated with diuretics, ACEinhibitors and calcium channel
blockers.
• Step one therapy: low-dose thiazide
diuretics (12.5 mg – 25 mg) or
thiazide-like diuretics.
• Step two and three therapy: cost
and compelling indications should
be considered first. If still uncomplicated, then ACE-inhibitors (or
angiotensin receptor blockers
[ARBs] in ACE-intolerant cases) OR
calcium
channel
blockers
(dihydropyridines or non dihydropyridines) should be added to the
thiazide diuretic.
• The combination of thiazide
diuretics and beta-blockers are now
discouraged especially in cases
where patients have abdominal
obesity because of the risk of
developing type two diabetes.
• Beta-blockers, such as atenolol, are
no longer considered as routine
step one to step three therapies due
to their risk of inducing type two
diabetes and relative ineffectiveness in reducing certain hard
endpoints. They also did not alter
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•
several outcomes reduced stroke by
about half of what was expected by
BP reduction. Beta-blockers also do
not reduce cardiovascular mortality
or myocardial infarct mortality when
given for hypertension.
Although other beta-blockers, such
as
the
alpha-beta
blocker
carvedilol, have no cardiovascular
outcome studies in hypertension, it
has been shown to have a positive
metabolic profile.
Currently the results of the
ONTARGET trial 2 are awaited to
further differentiate the use of ACEinhibitors plus ARBs. According to
these guidelines the ACE-inhibitors
and ARBs are equally effective and
cost and tolerability may be the only
determining factors.
Compelling indications for certain
drug groups
• Angina: beta-blocker OR rate
lowering calcium channel blocker.
• Previous myocardial infarct: betablocker AND ACE-inhibitor (or
ARB). Verapamil if beta-blockers
are contra-indicated.
• Heart failure: ACE-inhibitor (or ARB)
AND certain beta-blockers AND
aldosterone antagonist. Loop
diuretics for volume overload. ARB
plus ACE-inhibitor – specific
indications.
• ECG-confirmed left ventricular
hypertrophy: ARB (preferred) OR
ACE-inhibitor.
• Secondary prevention of stroke:
Low dose thiazide-like diuretic AND
ACE-inhibitor or ARB.
• Diabetes without microalbuminuria
or proteinuria: ACE-inhibitor OR ARB,
usually in combination with diuretic.
• Chronic kidney disease: ACEinhibitor OR ARB, usually in combination with diuretic.
• Isolated systolic hypertension: lowdose thiazide or thiazide-like
diuretic OR long-acting calcium
channel blocker.
Combination therapy
1. Effective blood pressure lowering
combinations are:
- Diuretic
and
beta-blocker
(although not advocated for step
one to step three).
- Diuretic and ACE-inhibitors or
ARBs.
-
2.
3.
4.
5.
6.
CCBs plus ACE-inhibitors.
Beta-blockade plus alphablockade.
Black patients respond best to
diuretics in combination with other
drugs.
Synergisms exist between ACEinhibitors or ARBs combined with
either calcium channel blockers or
diuretics.
Amlodipine plus ACE-inhibitor
(perindopril) was used in ASCOT 3
and showed superiority to atenolol
plus a thiazide diuretic.
In the VALUE-trial4 the CCB-diuretic
combination was better in reducing
myocardial infarctions than the
ARB-diuretic combination, but
induced more type 2 diabetes.
In PROGRESS 5 the combination of
an ACE-inhibitor and a diuretic was
better than an ACE-inhibitor alone.
Metabolic syndrome
This syndrome is characterised by
obesity, dyslipidaemia and type 2
diabetes together with hypertension.
The hypertension guideline provides
definite criteria and goals for treatment
of this disease entity.
Management of severe hypertension
A patient with a blood pressure of
>180/110 has severe hypertension and
should always immediately be
classified into one of three categories.
1. Asymptomatic severe hypertension
– no signs of acute target organ
damage. The patients should be observed in a care setting (GPs rooms
or clinic) for 1 hour. If the blood
pressure is still elevated – administer a thiazide diuretic plus a
dihydropyridine CCB. Re-evaluate
and follow-up within a week or
earlier. Refer if the blood pressure
is not controlled within 2-4 weeks.
2. Hypertensive urgency: Symptomatic
(headache, shortness of breath and
oedema). Refer to hospital.
3. Hypertensive emergency: Most
have blood pressure levels higher
than 220/140 mmHG and the acute
elevation is associated with
ongoing target organ damage. This
may include damage to
a) kidneys (anuria or blood in
urine),
b) brain (stroke – any paralysis or
paresis, check pupil sizes, or
SA Pharmaceutical Journal – May 2006
CLINICAL
changed level of consciousness
or severe headache),
c) heart (heart attack, unstable
angina, arrhythmias, acute heart
failure), and/or
d) eyes (visual disturbances,
retinopathy on ophtalmoscopy).
These patients need urgent
emergency medical attention
and should be transported to
hospital in an ambulance.
•
•
Management of resistant (refractory)
hypertension
Defined as blood pressure that is
>140/90 mmHg despite three antihypertensive drugs. Pharmacists play a
crucial role in determining compliance
with medication and lifestyle changes
and in identifying drug-induced hypertension. An excellent table that
summarises common causes of
resistant hypertension is included in
the guidelines.
Special considerations in certain
populations
• Blacks and Indians: Blacks respond
better to thiazide diuretics and
CCBs. They may respond poorly to
beta blockers or ACE-inhibitors
when prescribed as monotherapy.
Type two diabetes and the
metabolic syndrome are more
prevalent in the Indian population.
Children and adolescents: The
hypertension guidelines are mainly
for adults, but a table is included
that allows healthcare workers to
identify cases at risk. Using the
correct cuff size is very important.
Hypertension in children needs
immediate specialist attention.
Patients living with HIV/AIDS:
Taking blood pressure of patients
on HAART is very important,
because this regimen is known to
increase systolic blood pressure.
Drug interactions between ARV’s
(protease inhibitors and nonnucleoside reverse transcriptase
inhibitors) and CCBs are well
documented.
Conclusion
The pharmacist plays an enormous role
in the successful treatment and
management of hypertensive patients.
Compliance and availability of drugs
are two major aspects of successful
therapy. The national guidelines
should be studied to standardise the
pharmacist’s approach to the hyper-
tensive patient. Compliance with
lifestyle modifications and drug
therapies should always be advocated.
Interactions with over-the-counter
drugs and other chronic medications
should always be excluded.
Compiled by DGS Greeff, Medical Writer,
Medpharm Publications
REFERENCES
1. Seedat YK, Croasdale MA, Milne FJ et al. South
African Hypertension Guideline 2006. S Afr Med
J 2006;96(4)337-362.
2. Teo, K, Yusuf S, Sleight P, et al. Rationale,
design, and baseline characteristics of 2 large
simple, randomized trials evaluating telmisartan,
ramipril, and their combination in high-risk
patients: the Ongoing Telmisartan Alone and in
Combination with Ramipril Global Endpoint
Trial.Telmisartan Randomized Assessment Study
in ACE Intolerant Subjects with Cardiovascular
Disease (ONTARGET/TRANSCEND) trials. Am
Heart J 2004; 148: 52-61.
3. Dahlof B, Sever PS, Poulter NR, et al. Prevention
of cardiovascular events with an antihypertensive
regimen of amlodipine adding perindopril as
required
versus
atenolol
adding
bendrofulmethiazode as required, in theAngloScandinavian Cardiac Outcomes Trial-BP
Lowering Arm (ASCOT-BPLA): a multicentre
randomized controlled trial. Lancet 2005; 366:
895-906.
4. Julius S, Kjeldsen SE, Weber M, et al. Outcomes
in hypertensive patients at high cardiovascular
risk treated with regimens based on valsartan or
amlodipine: the VALUE randomised trial. Lancet
2004; 363: 2022-2031.
5. PROGRESS Collaborative Group. Randomised
trial of a perindopiril-based blood-pressure
lowering regimen among 6105 individuals with
previous stroke or transient ischaemic attack.
Lancet 2001; 358: 1033-1104.
Drug ALERT
Oral decongestant use during pregnancy
A recently published large epidemiological study in 4213 women has found no association between the use of oral
decongestant medicines in pregnancy and an increased risk of malformations.
Between 1995 and the end of 2002, pregnant women who had used an oral decongestant, mainly phenylpropanolamine,
were identified. Most women (2442) had used the medicine during early pregnancy while 1771 used it in later pregnancy.
Among the infants exposed to oral decongestant medicines:
• There were 117 identified malformations (4.7%) compared with an expected number from the general population of 121.3
malformations in the infants born to women who had used the oral decongestant in early pregnancy.
• In later pregnancy, the rates of prematurity, being small-for date or stillbirth were all lower than expected.
The authors concluded that the use of oral decongestants during pregnancy is not associated with any statistically significant
increase in the risk of malformations in the infant. Unexpectedly, the use of these medicines was shown to be associated with
a better outcome when used in later pregnancy. While this finding may be an artefact of multiple testing, it could also be
explained by use for pregnancy rhinitis, which may in turn be a marker for healthy placental function.
REFERENCE:
Glare J. Oral decongestant use during pregnancy not associated with increased malformation risk.
Am J Obs Gynecol 2006;194:480-485.
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SA Pharmaceutical Journal – May 2006