Pediatric
Pharmacology
Recommendations for children prescribing
Dept. Pharmacology & Therapeutic
School of Medicine
“Remember that is
“Remember that is
child is a child,
child is a child,
and
and
NOT
Faktor-faktor Individual Yang
Mempengaruhi Dosis Dan Tindakan Obat
• Umur dan berat badan
• Body surface area
• Jenis kelamin
• Waktu dan faktor tempat
• Faktor fisiologik
• Toleransi
– Toleransi kongenital – Toleransi perolehan – Toleransi silang
– Takifilaksi (toleransi akut)
• Kumulasi
• Faktor fisiologik
• Faktor patologik
• Faktor farmakogenetik
(idiosinkrasi)
• Faktor imunologik (alergi
obat)
• Faktor psikologik dan
lingkungan
• Kumulasi
• Faktor farmakokinetik:
Half-life
(1
1/2)
• Kombinasi obat:
– addisi – potensiasi – sinergisme – antagonisme – interaksi obatAnak vs Dewasa
Anak vs Dewasa
•
anak bukanlah miniatur dewasa
•
masih dalam proses tumbuh kembang, sehingga
fungsi organ dan keadaan fisiologis lainnya juga
masih berkembang
–
imaturitas fungsi organ-organ tubuh
•
respons anak terhadap pemberian obat
•
respons anak terhadap pemberian obat
–
kejadian efek samping lebih nyata
•
perlu penghitungan dosis
– Banyak obat yang digunakan pada orang dewasa
belum dikaji secara tuntas
•
formula obat,
Adverse drug reaction surveillance in pediatric
and adult patients in an emergency room
Munoz et al. Med Clin (Barc) 111(3):92-8,1998
Drugs
Children
Adults
NSAID
10.4%
28.2%
Dangerous Drugs
Dangerous Drugs
NSAID
10.4%
28.2%
CV drugs
?
15.9%
Antimicrobials
49.5%
14.5%
GIT drugs
?
11.1%
Respiratory drugs
19.9%
?
Vaccines
9.2%
?
NSAID ADR-related hospitalizations
Pediatric drug development
• Must include all aspects of general drug
development (usually referenced)
• Plus must evaluate:
– Differences in absorption, distribution,
– Differences in absorption, distribution,
metabolism, elimination
• PK profile for age
– Differences in side effect profile
– Differences in therapeutic effect
Efek umur, sex dan tipe tubuh terhadap komposis tubuh
Umur BB rata (kg) Air tubuh total Lemak
(th) (% BB) (% BB)
Bayi < dari 3 bulan 3,5-8,3 70
Balita 1 10 57 Pria 20-30 72 58 19 40-50 77 56 25 60-70 77 54 25 Wanita 16-30 58 52 29 40-50 62 49 35 60-70 64 42 45 Pria gemuk 31 100 49 33 Pria langsing 26 69 70 7
Ontogeny of Body Composition
Ontogeny of Body Composition
Kaufman, Pediatric Pharmacology (Yaffe & Aranda, eds) pp. 212-9, 1992
EC H2O IC H2O Protein Other Fat Premature Newborn 4 mo
% of Total Body Weight
0 20 40 60 80 100 4 mo 12 mo 24 mo 36 mo Adult
Pharmacokinetic
Oral Drug Absorption
Drug Absorpsion
Para Para--meter meter Neo Neo--natus natus InfantInfant ChildChild
Gastric Acid Secretion Reduce Decrease Reduce Normal Increased Normal Normal Increased Normal
Neonate vs. Older Children
Drug
Drug Oral AbsorptionOral Absorption
Acetaminophen Decreased Ampicillin Increased Diazepam Normal Secretion Gastric Emptying time Intestinal Motility Billiary Function Microbial Flora Reduce Reduce Acquiring Normal Normal Adult Pattern Normal Normal Adult Pattern Diazepam Normal Digoxin Normal Penicillin G Increased Phenobarbital Decreased Phenytoin Decreased Sulfonamides Normal
CYP3A Ontogeny
LaCroix D et al. Eur J Biochem 247:625, 1997
Fetus
Postnatal Age
CYP3A7
CYP3A7
CYP3A4
CYP3A4
1 1.5 0.1 0.15 < 3 0 w > 3 0 w < 2 4 h 1 -7 d 8 -2 8 d 1 -3 m o 3 -1 2 m o > 1 y r A d u lt
CYP3A7
CYP3A7
Activity
Activity
CYP3A4
CYP3A4
Activity
Activity
0 0.5 0 0.050.3
G:S
Acetaminophen Metabolism
Acetaminophen Metabolism
Miller et al., Clin Pharmacol Ther 19:284-94, 1976
0.15
k
el Newborn Acetaminophen Glucoronide Sulfate 0.75 1.6 1.8 0.17 0.19 0.18% of Dose
0 20 40 60 80 100 3-9 years 12 years AdultsWhy are children at greater risk of
Why are children at greater risk of
medication errors?
medication errors?
•
Drug doses calculated individually
– Based on age, weight, surface area
– More calculations
– Weights change rapidly (esp neonates)
– 10-fold errors
•
Inadequate information
•
Inadequate information
•
Incorrect use of dose information resources
•
Lack of suitable dosage forms and concentrations
•
Need for complex calculations & dilutions by
medics/nurses
•
Children can’t always tell us
– if we’re about to make a mistake
– if they suffer adverse effects
•
Children have less internal reserves with which to ‘buffer’
the effects of errors
Most common error type
Most common error type
Dosing errors
28 %
Route of administration
18 %
MAR transcription
14 %
& documentation
& documentation
Wrong date
9.9 %
Frequency
9.4 %
Calculation of Pediatric Drug Dosage
based on age
•
Young
:
– n / [n + 12] x dosis dewasa (n = umur tahun)
– berlaku untuk anak: 1 – 8 tahun, tidak cock untuk diatas 12 tahun
•
Dilling
:
– n / 20 x dosis dewasa (n = umur tahun)
– berlaku untuk anak : 8 – 20 tahun
•
Cowling
:
•
Cowling
:
– [n + 1] / 24 x dosis dewasa (n = umur tahun)
– di Indonesia rumus ini tidak banyak dipergunakan.
•
Rumus Ausberger
: rumus ini agak tepat untuk anak umur
– 2 – 12 bulan: (m + 13) % dari D – 1 – 11 tahun: (4n + 20) % dari D – 12 – 16 tahun: (5n + 10) % dari D
– m = umur dalam bulan; n = umur dalam tahun; D = dosis dewasa
•
Fried
:
– m / 150 x dosis dewasa ( m = umur bulan)
Calculation of Pediatric Drug Dosage
Calculation of Pediatric Drug Dosage
based on body weight
Clark’s rule Kg
weight (kg)
Ped. dose = ––––––––––––––––––––– X adult dose
70
pound Weight (pound)
Ped. dose = ––––––––––––––––––––– X adult dose
BSA Body surface area
neonate BSA
Ped. dose = ––––––––––––––––––––– X adult dose
adult BSA
150
•
Luas permukaan badan dari anak:
Calculation of Pediatric Drug
Calculation of Pediatric Drug
Dosage based on BSA
Dosage based on BSA
Weight
(kg)
Age
BSA
(m
2)
% adult
dose
3
Born
0,2
12
6
3 month
0,3
18
10
1 year
0,45
28
10
1 year
0,45
28
20
5,5 year
0,8
48
30
9 year
1
60
40
12 year
1,3
78
50
14 year
1,5
90
60
Adult
1,7
102
70
Adult
1,76
103
•
Luas permukaan badan dari anak:
Calculation of Pediatric Drug Dosage
Young’s rule:
dose = adult dose x (age in years)/(age
+ 12)
Clark’s rule:
dose = adult dose x weight (kg)/70
dose = adult dose x weight (lbs)/150
Body surface area
(neonate BSA/adult BSA) x 100 = % of adult
dose needed
Young’s Rule
(untuk anak-anak 2-12 tahun)
mg
100
12
3
500
x
3
thn
3
umur
untuk
mg)
500
:
oral
dewasa
(dosis
l
Parasetamo
:
Contoh
12
Umur
dewasa
dosis
x
(thn)
Umur
anak
-anak
Dosis
=
+
=
+
=
Contoh menghitung dosis PARASETAMOL untuk anak
12
3
+
Hamburger’s Rule (didasar kan pada berat badan dengan berat Badan de wasa 70 kg.
mg
100
70
500
x
14
dosis
mg);
500
:
oral
dewasa
(dosis
kg
14
berat
dengan
anak
-anak
untuk
l
parasetamo
dosis
menghitung
:
Contoh
70
dewasa
dosis
x
(kg)
Berat
Dosis
=
=
=
Body Surface Area Rule. Meski penentuan dosis berdasarkan berat bdan lebih akurat ketimbang umur, namun banyak variasi berat yang berkaitan dengan umur. Jadi untuk menentukan dosis yang paling tepat untuk anak-anak adalah dengan body surface area (BSA), formula: 7 , 1 M 1,7 dewasa dosis x anak) -anak (M BSA anak -anak Dosis 2 2 − = = = dewasa orang pada rata rata BSA BSA sangkar bujur meter mg 30 7 , 1 6 , 51 1,7 60 x 0,86 dosis ); M 0,86 : nomogram dari (BSA nomogram dari BSA tentukan mg, 60 dewasa dosis dan inci) 47 (tinggi pounds 50 berat dengan anak -anak untuk dosis menghitung : Contoh ) ( 7 , 1 2 = = − = dewasa dosis untuk digunakan sama yang formula dewasa orang pada rata rata BSA
Semua formula di atas hanya prakiraan saja, yang selanjutnya
Perlu disesuaikan secara individual pada pasien. Tidak ada formula yang betul-betul tepat untuk menghitung dosis untuk bayi prematur dan neonat <2 minggu.
Special Dosage Forms for
Pediatrics
•
Elixirs
•
Suspensions
–
Sweeteners
•
Induce infection
and dental carries
–
Alcohol
•
Chewable tablets
•
Patient
Compliance
•
Measured spoon
–
Teaspoon
–
1 Cth = 5 ml
–
1 C = 15 ml
Sendok
Sendok Makan
Makan &
& Sendok
Sendok Teh
Teh
di
di Hotel
Hotel -- Rumah
Rumah Tangga
Tangga
• Ukuran volume 1 sendok makan: tidak ada
ukuran 15 ml
• Ukuran volume 1 sendok teh (seharusnya 5 ml)
sangat bervariasi
KETEPATAN SENDOK TAKAR 5 (LIMA)
MILLILITER SEDIAAN CAIR (SYRUP) DARI
BERBAGAI PERUSAHAAN FARMASI
Sake Juli Martina, Aznan Lelo, Dayat S Hidayat (2007)
3 4 5 6 v o lu m e ( m l) 0 1 2 < cth cth > cth classification of "cth" v o lu m e ( m l)
•
Dari 70 sendok takar yang berbeda dari 38 Perusahaan
Farmasi didapatkan hasil bahwa :
– 4,3 % volume < 5 ml (4,4 ± 0,2 ml); – 75 % volume = 5 ml ;
Distribusi Volume (ml) sendok takar dari
Distribusi Volume (ml) sendok takar dari
berbagai perusahaan Farmasi
berbagai perusahaan Farmasi
Perusahaan
Farmasi
Jumlah
Sendok
Volume (ml)
terkecil terbesar
Ethica
1
4,2
Sampharindo perdana
1
4,4
Bufa Aneka
1
4,6
Kimia Farma
9
5
5
Mutifa
1
5,6
Nufarindo
1
5,6
Universal
3
5
5,8
Sanbe Farma
8
5
6
Phapros
2
5,2
5,4
Improving Medical Products for
Improving Medical Products for
Children
Children
• It’s important to use
the measuring device
that comes with a
that comes with a
child’s medicine.
Drug
Suggested dosages of some NSAIDs
Suggested dosages of some NSAIDs
for postoperative pain management
for postoperative pain management
NSAID
Dose
Route
Diclofenac
0.7 - 2 mg/kg
Oral, Rectal, IM
Ibuprofen
5 - 10 mg/kg
Oral
Flurbiprofen
1 mg/kg
Oral
Flurbiprofen
1 mg/kg
Oral
Ketorolac
0.3 – 0.5 mg/kg
IM, IV
Ketoprofen
1 – 2 mg/kg
IV
Naproxen
4 - 6 mg/kg
Oral
Nimesulide
1.5 mg/kg
Oral
Tenoxicam
0.75 mg/kg
IM
Kokki H. Nonsteroidal anti-inflammatory drugs for postoperative pain. A focus on children. Pediatr Drugs 5(2):103-23,2003
Bahan aktif yang ditambahkan
pada obat-obatan untuk anak
Obat racikan
–
Saccharum lactis
Obat jadi
•
Syrup
•
Alcohol, as a
solvent
•
Fluoride
•
Syrup
–
Flavors
–
Alkohol
•
Tablet kunyah
–
Flavors
–
Pemanis rasa
•
Fluoride
•
Thimerosal in
vaccinations
Anak
Anak: 4
: 4 tahun
tahun &
& berat
berat badan
badan 15 kg
15 kg
diclofenac
• Dosis per- hari adalah:
– (0,7 – 2) mg/kg x 15 kg = (10.5 - 30) mg
– dosis terbagi 3 kali sehari,
ibuprofen
• Dosis per- hari adalah:
– (5 – 10) mg/kg x 15 kg = (75 – 150) mg
– dosis terbagi 3 kali sehari, – dosis terbagi 3 kali sehari,
(3.5 – 10) mg per-kali
R/ Diclofenac
mg 5
Saccharum lactis qs
m f pulv dtd
No X
S 3 dd pulv I
– dosis terbagi 3 kali sehari, (25 – 50) mg per-kali
R/ Ibuprofen
mg 50
Saccharum lactis qs
m f pulv dtd
No X
CATAFLAM DROPS
CATAFLAM DROPS
((Diclofenac
Diclofenac resinate
resinate))
Children are at greater risk of medication errors
Several aspects that need attention in children’s drug
administration are physiological development, pharmacokinetic, pharmacodynamic, desired therapy result
Pharmacokinetic and pharmacodynamic affect the drug dosage, route and frequency of administration, and duration of treatment Newborn babies need special attention in drug administration due Newborn babies need special attention in drug administration due
to their immature physiological function
Accurate Dosage calculation is essential in children drug therapy. It can be acquired from three formulas : based on body weight,body surface area, and age
Several drug administrations are via oral route, rectal route and parenteral route
Improving medical products for children is needed
Convenience in calculating doses for children, such as one drop/kg body weight/administration