2nd Joint Annual Meeting Club Phase I and AGAH Positioning Human Pharmacology for the Future Bad Hom

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2nd Joint Annual Meeting Club Phase I and
AGAHPositioning Human Pharmacology for the
FutureBad Homburg v.d.H., April 26 and 27, 2007

H. W. Seyberth Department of Pediatrics Philipps
University, Marburg/Germany
Workshop Designs of human pharmacology trials
for paediatric populations
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Physiology, Diseases and Developmental
Pharmacology
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Appreciation of at least five phases of
development
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Very Preterm Newborn Phase of survival born at lt
27 weeks of gestation
Physiology Large body surface
Increased skin permeability Reduced
surfactant synthesis Aortopulmonary
shunts Immaturity of the brain stem No
ciruclatory autoregulation Incomplete retinal
vascularisation
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Very Preterm Newborn Phase of survival born at lt
27 weeks of gestation
Pathophysiology Respiratory
distress Pulmonary hypertension Patent ductus
arteriosus Apnea Intraventricular
hemorrhage Retinopathy of prematurity
(ROP) Bronchopulmonary dysplasia
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Term Newborn Phase of Adaptation age birth up
to 1 month Physiology Large body
surface Increased skin permeability Increased
body water Decreased blood brain
barrier Incomplete neuronal maturation Increas
ed hemolysis
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Term Newborn Phase of Adaptation age birth up
to 1 month
Pathophysiology Sepsis Hyperbilirubinemia
Seizures Hypocalcemia Hypoglycemia Malformat
ions
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Infants and Toddler Phase of proliferation and
growth age 22 days to 24 months Physiology
Small airways Ongoing cerebral
myelination Naive (incompetent) immune
system Large liver and kidney (increased
clearances)
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Infants and Toddler Phase of proliferation and
growth age 22 days to 24 months
Pathophysiology Otitis media Bronchiolitis
Febrile seizures Rickets
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Children Phase of Differentiation and
Training age 2 to 11 years Physiology Slowe
r growth rate Increased independence Increased
school performance Shift to logical operations
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Children Phase of Differentiation and
Training age 2 to 11 years
Pathophysiology Accidence Dysfunctions of
the immune system Asthma/allergy Juvenile
rheumatoid arthritis Autoimmune
diseases Neoplasm Hyperkinesia Enuresis Or
gan transplantations Epileptic
syndromes Obesity Diabetes
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Adolescents Sexual Maturation age 12 to 17
years Physiology Rapid body
changes growth spurt gonadal
growth Emotional instability
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Adolescents Sexual Maturation age 12 to 17
years Pathophysiology Acne
vulgaris Endocrine dysfunctions Accidence Se
xual transmitted diseases Drug
addiction Doping
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Adolescent 12 - 17 years
Pre-term Infant lt 36 weeks of gestation
Term Newborn Infant 0-27 days
Infant/Toddler 28 days -23 months
Child 2 - 11 years
Adaptation
Growth
Survival
Training
Maturation

Seyberth, in Pädiatrie, eds Speer/Gahr, 2005
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Pharmacokinetic differences in the term and
preterm infants
Absorption ? Gastric HCI-production
? Bile flow ? Bacterial intestinal
growth ? Enterohepatic
circulation Distribution ? Body
water ? Body fat ? Muscular
mass ? Plasma protein binding Liver
metabolism ? Hydroxylation ?
Glucoronidation Renale excretion
? GFR ? Tubular function
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An important dosage-principle in the NICU

• Given
• Result
• Examples

• Vd ?
• Clearance ?
• Loading dose (LD) ?
• Maintenance dose (MD) ?
• Phenobarbital, Phenytoin, Methylxanthine,
  Digoxin, Aminoglykoside, Indometacin
  Chloramphenicol, Furosemide

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THEOPHYLLINE
Maintenance dose of drugs with renal elimination
Total body clearence
DIGOXIN
(ml/h/kg)
(µg/kg/day)
-
100
-
20
-
75
-
15
-
50
-
10
-
-
25
5
0
0
-
-
-
-
-
Preterm term neonates
Adults (gt 50 y)
Young children (lt 8 y)
Adults (lt 50 y)
(mg/kg/day)
Maintenance dose
GENTAMYCINE
(mg/kg/day)
-
30
-
10
-
20
-
5
-
10
0
0
Preterm term neonates
Young children (lt 8 y)
Adults (gt 50 y)
Adults (lt 50 y)
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PHARMACOKINETICS
PHARMACODYNAMICS
Resorption
Receptor
Distribution
Excretion
Signal transduction
Cellular reaction
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Medium analgesic dosage of morphine in children
with an age between 0 and 6 years
p lt 0.01
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dosis 0.05 mg/kg/min infusion rate until
painlessness
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Morphine plasma concentration µg/l at time
point of pain recovery
10
0
0 - ½ year n 5
6 year n 4
2 - 4 year n 5
(Olkkola et al., CPT 1988)
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Indomethacin induces GFR reduction in young
adults with volume depletion and in preterm
infants with sPDA
2 mg/kg/d
without indo
100
with indo
- 12
91
GFR ml/min/1.73m2
80
80
60
40
0.2 mg/kg/d
20
- 40
19.5
11.7
adults
infants
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Congenital salt losing tubulopathies
(SLTs) Different age at manifestation and
ontogeny of targets
(Jeck et al., AJ
P 2005)
Thiazid-SLT NCCT
Furosemid-SLT NKCC2

lt1 year 1/13 1-5 years 4/13
6-13 years 8/13
Age at first presentation
antenatal 12/12


polyuria hyponatremia hypotension (shock)
hypercalciuria nephrocalcinosis
hypokalemia carpopedal spasms hypomagnesemia hypo
calciuria growth retardation
Postnatal leading symptoms
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Adverse effects of geriatric heart failure
therapy applied to preterm infants with sPDA
fluid restriction
furosemide

digoxin
NSAIDs ACE- inhibitor
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Pre-renal failure in the preterm infant with sPDA
filtration
v. afferens
v. efferens
angiotensin II
prostaglandins
vasodilation
vasoconstriction
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Examples on long-term adverse effects of
medicines in early infancy and childhood
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There are marked differences in pediatric
patiants with respect to
- Pharmacokinetics
- Pharmacodynamics
- Drug toxicity
- Longterm safety