Transcript Treatment of Hypertension in Children

Treatment of Hypertension
in Pediatrics
Kelsey R. Green, Pharm.D.
Pediatric Clinical Pharmacist
LSU-HSC in Shreveport, LA
Objectives
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Define hypertension in children
Identify when blood pressure should
be taken
Practice determining BP percentile and
interpreting how to use this
information to best treat the patient
Discuss treatment options used in
pediatrics to treat hypertension
Definitions2
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Hypertension: average SBP and/or
DBP >95th percentile for gender, age,
and height on > 3 occasions
Prehypertension: average SBP or DBP
>90th percentile but <the 95th
percentile
– Adolescents with BP levels >120/80 mm
Hg should be considered prehypertensive
Measurement of Blood
2
Pressure
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Children >3 years old should have
their BP measured when seen in a
medical setting
Preferred method: Auscultation
– Requires a cuff that is appropriate for the
child’s arm
– Right arm preferred
Blood Pressure Cuff2
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Equipment needed to
measure BP in children
(3-adolescents):
– Child cuffs of different
sizes
– Standard adult cuff
– Large adult cuff
– Thigh cuff
Measurement of BP in
2
children < 3 years old
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History of prematurity, VLBW, or other neonatal
complications
Congenital heart disease
Recurrent UTI, hematuria, or proteinuria
Known renal disease or urologic malformations
Family history of congenital renal disease
Solid-organ transplant
Malignancy or bone marrow transplant
Treatment with drugs known to raise BP
Systemic illnesses associated with hypertension
Evidence of elevated ICP (intracranial pressure)
Using the Blood Pressure
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Tables
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Use the standard height charts to determine the
height percentile.
Measure and record the child’s SBP and DBP.
Use the correct gender table for SBP and DBP.
Find the child’s age on the left side of the table.
Follow the age row across the table to the
intersection of the line for the height percentile.
Find the 50th, 90th, 95th, and 99th percentiles for
SBP in the left columns and for DBP in the right
columns.
Let’s Practice
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AMF is a 5 yo female weighing 25 kg
in the 75th percentile of height. Her
BP is taken when she goes to the Dr.
for a routine visit. Her BP is 114/73.
What is her BP percentile?
What do we do with this information?
What does this percentile
2
mean?
Normal
<90th
Prehypertension
90-<95th or if >120-80
Stage 1 hypertension
95th-99th plus 5 mm
Hg
Stage 2 hypertension
>99th plus 5 mm Hg
Classification of
Hypertension & Therapy
Recommendations2
Classification of
Hypertension
Therapy Recommendations
Normal
Encourage healthy diet, sleep, & physical
activity
Prehypertension
Physical activity & diet management; No
medication unless compelling indications
such as chronic kidney disease, DM, HF or
LVH exist
Stage 1 Hypertension
Physical activity & diet management;
Initiate therapy
Stage 2 Hypertension
Physical activity & diet management;
Initiate therapy (more than 1 drug may be
required)
Management Algorithm2
Diagnostic Work-Up6
Urinalysis
Protein/Cr Ratio
Renal Ultrasound
EKG
CBC with differential
Electrolyetes, BUN,
Cr
Rule out infection, hematuria,
proteinuria
Kidney function
Rule out renal scarring,
congenital renal anomalies
Cardiomegaly
Rule out anemia, consistent
with chronic renal disease
Rule out renal disease,
pyelonephritis
Possible Etiologies
2
Causing Hypertension
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Chronic Renal Failure
Cushing Syndrome
Turner Syndrome
Hyperthyroidism
Systemic Lupus
Coarctation of the aorta
Wilms tumor
Treatment Strategies
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Therapeutic lifestyle changes
Drug therapy
Lifestyle changes
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Weight reduction
Regular physical activity
Restriction of sedentary activity
Dietary modification
Family-based intervention
Indications for
Antihypertensive Drug
Therapy2
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Symptomatic hypertension
Secondary hypertension
Hypertensive target-organ damage
Diabetes (types 1 and 2)
Persistent hypertension despite
nonpharmacologic measures
Step-wise Approach to
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Therapy
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Start with a small dose of a single
anti-hypertensive drug
Increase dose of single antihypertensive drug (to max dose if
tolerated)
Add a small dose of a second drug
Increase dose of second antihypertensive medication
Antihypertensive
Medication
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Angiotensin Converting EnzymeInhibitors
Angiotensin Receptor Blockers
Calcium Channel Blockers
Diuretics
Beta-Blockers
Central alpha-agonists
Peripheral alpha-antagonist
Vasodilators
Drug Options for Initial
1
Therapy
Class of
Patients’ Characteristics
Drugs
ACE-Is/ARBs First-line therapy
CCBs
First-line therapy
Diuretics
Adjunct second-line drug
β–Blocker
Avoid in athletes (controversial)
and people with diabetes
ACE-I1-3, 5
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Angiotensin Converting Enzyme Inhibitors
Benazepril*, Captopril, Enalapril*,
Fosinopril*, Lisinopril*, Quinapril
Mechanism of Action: prevents conversion of
angiotensin I to angiotensin II, a potent
vasoconstrictor; results in lower levels of
angiotensin II which causes an increase in plasma
renin activity and a reduction in aldosterone
secretion
ACE-I
www.medscape.com
ACE-I
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Patient’s Characteristics:
– High plasma renin activity
– Renal insufficiency (unilateral
renovascular hypertension, renal
parenchymal disease, renal proteinuria)
– Congestive heart failure
– Diabetes
– Hyperlipidemia
ACE-I
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Comments:
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Contraindicated in pregnancy
Monitor serum potassium and SCr
Cough and angioedema
May require a dosing adjustment in renal
impairment
– Fosinopril in children >50 kg
– Good data on compounding Captopril into a
suspension
ARB1-3, 5
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Angiotensin Receptor Blockers
Irbesartan*, Losartan*
Mechanism of Action: angiotensin II
receptor antagonist; blocks the
vasoconstrictor and aldosteronesecreting effects of anigotensin II
ARB
www.medscape.com
ARB
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Patient’s Characteristics: same as
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Comments:
ACE-I
– Less studied than ACE-I
– Dosing not available in Neofax or Pediatric
Dosing Handbook
– All are contraindicated in pregnancy
– Check serum potassium and SCr
– Not available currently on formulary
CCB1-3, 5
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Calcium Channel Blocker
Amlodipine*, Felodipine, Isradipine,
Extended-release Nifedipine
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Mechanism of Action: inhibits calcium
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ions from entering the “slow channels” or select
voltage-sensitive areas of vascular smooth muscle
and myocardium during depolarization; produces
a relaxation of coronary vascular smooth
muscle and coronary vasodilation
CCB
http://calcium.ion.ucl.ac.uk/images/contractionsmc.gif
CCB
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Patient’s Characteristics:
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Emergency hypertension (nifedipine)
Black race
Diabetes
Chronic obstructive lung disease
Broncho-pulmonary dysplasia
Gout
Hyperlipidemia
Peripheral Vascular Disease
Renal Transplant (cyclosporine-induced)
CCB
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Comments:
– ADR: edema, arrhythmias, headache,
fatigue, dizziness, flushing
– No adjustment in renal impairment
– May need adjustment in hepatic
impairment
– Good data for compounding Amlodipine
oral suspension
Diuretics1-3, 5
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Amiloride, Chlorothiazide, Chlorthalidone,
Triamterene, Furosemide, HCTZ*,
Spironolactone, Metolazone,
Bumetanide
Mechanisms of Action:
– Loop Diuretic: (Furosemide, Bumetanide) Inhibits
reabsorption of Na and Cl in the ascending loop of
Henle and distal tubule – causing increased excretion
of water, K, Na, Cl, Mg, & Ca
Diuretics
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Mechanism of Action: continued
– Thiazide Diuretic: (HCTZ, Chlorothiazide) Inhibits Na
reabsorption in the distal tubules causing increased
excretion of Na and water as well as K, Mg, Ca, hydrogen,
phosphate, & bicarb ions
– K Sparing Diuretic: (Spironolactone) Competes with
aldosterone for receptor sites in the distal renal
tubules, increasing NaCl and water excretion while
conserving K and hydrogen ions; may block the effect of
aldosterone on arteriolar smooth muscle as well
– Miscellaneous: (Metolazone) Inhibits sodium
reabsorption in the cortical diluting site and proximal
convoluted tubules
Diuretics
http://sprojects.mmi.mcgill.ca/nephrology/prese
ntation/images/86no2.gif
Diuretics
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Patient’s Characteristics:
– Volume dependent, low plasma renin
activity
– Black race
– Congestive heart failure
– Avoid in athletes
Diuretics
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Comments:
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ADR: Dizziness, Photosensitivity, Rash, Vomiting
Monitor Electrolytes
Adjust in renal impairment
Furosemide and Chlorothiazide available in
solutions
– Good data to compound Spironolactone,
Metolazone and HCTZ into oral suspensions
BB 1-3, 5
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Βeta-Blocker
Atenolol, Bisoprolol/HCTZ, Metoprolol,
Propranolol*
Mechanism of Action: Selective
inhibitor of beta1-adrenergic receptors
at lower doses; also inhibits beta2receptors at higher doses
BB
http://www.eaaknowledge.com/ojni/ni/602/strate1.jpg
BB
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Characteristics:
– High plasma renin activity
– Hyperdynamic circulation
– Anxiety
– Migraine
– Hyperthyroidism
– Neuroadrenergic tumors
BB
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Comments:
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Good data to compound Metoprolol and Atenolol
Propranolol available as a solution
Worried about higher doses in asthma patients
Contraindicated in sick sinus syndrome
Avoid in athletes and people with diabetes
Goals of Therapy2
Disease State
Desired Percentile for
Gender, Age, & Height
Uncomplicated primary HTN
with no target-organ damage
<95th Percentile
Chronic renal disease, diabetes, <90th Percentile
hypertensive target-organ
damage
Long-Term Management3
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Monitor therapy for efficacy and for
potential adverse effects
Measure blood pressure every 2-4
weeks until good control
Once controlled, monitor every 3-4
months
Step-Down Therapy2
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After blood pressure is stable,
gradually reduce medication
Goal: Discontinue medication
Best Candidates: Children with
uncomplicated HTN due to obesity
Continue to follow BP and continue
lifestyle changes
Our Patient
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AMF – BP was in 95th percentile
Repeated BP at 3 office visits (93rd
percentile)
Recommend Lifestyle Changes
Repeat BP in 6 months (95th percentile)
Patient work-up – unilateral renovascular
hypertension
Start an ACE-I
Conclusions
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Use patient’s BP Percentile to
determine if they have hypertension.
First-line agents to treat hypertension
are ACE-I/ARB or CCB.
Diuretics are usually used as second
line therapy.
References
1. Seikaly, Mouin G. Hypertension in children: an update on treatment
strategies. Curr Opin Pediatr 2007; 19:170-177.
2. National High Blood Pressure Education Program Working Group on
High Blood Pressure in Children and Adolescents. The fourth
report on the diagnosis, evaluation, and treatment of high blood
pressure in children and adolescents. Pediatrics 2004; 114:555576.
3. Flynn, JT. Pharmacologic Treatment of Hypertension in Children and
Adolescents. J Pediatr 2006; 149:746-54.
4. McNiece, Karen and Portman R. Ambulatory blood pressure
monitoring: what a pediatrician should know. Curr Opin Rediatr
19:178-182.
5. Pediatric Dosage Handbook, 14th ed. Hudson, OH: Lexi-Com, 2005.
6. Luma, GB and Spiotta, RT. Hypertension in Children and
Adolescents. AAFP 2006; 73: 1158-68.
Questions