3. • Children are not small adults.
• Patient details such as age, weight and surface
area need to be accurate to ensure appropriate
dosing of medicines.
• Weight and surface area may change in a relatively
short time period and necessitate dose adjustment.
• Pharmacokinetic changes in childhood are
important and have a significant influence on drug
handling and need to be considered when
choosing an appropriate dosing regimen for a child.
• The use of an unlicensed medicine in children is
not illegal, although it must be ensured that the
choice of drug and dose is appropriate.
KEY POINTS
3
7. Pediatric population
• Children are not just little adults
– Although most marketed drugs are used in
pediatric patients, only one of fourth of the
drugs approved by U.S. FDA
– Lack of data on important PK and PD
differences has led to several disastrous
situations in pediatric care.
7
8. 8
Pharmacokinetic- Absorption
Oral
absorption
Gastric and intestinal transit time ≒adult: 6 months of age
Gastric and intestinal pH ≒adult: second year of life
Intramuscular
absorption
Muscular blood flow Unpredictable
Muscle mass Unpredictable
Topical
absorption
Stratum corneum Inverse related
Skin hydration Direct related
Rectal
absorption
Similar to GI tract
Erratically absorbed
Rapid onset
10. 10
Extracellular fluid volume and total body water
as a percentage of BW at different life stages
Clinical Pharmacy and Therapeutics
Pharmacokinetic- Distribution
13. Pharmacokinetic- Distribution
• The amount of body fat is lower in
neonates than in adults
– Highly lipid-soluble drugs are distributed
less widely in infants than in adults
13
15. Pharmacokinetic- Metabolism
• Drug metabolism is substantially slower
in infants than in older children and
adults.
• There are important differences in the
maturation of various pathways of
metabolism within a premature infant
15
16. • Reduced capacity for metabolic degradation
at birth is followed by a dramatic increase in
the older infant and young child.
16
Pharmacokinetic- Metabolism
Clinical Pharmacy and Therapeutics
22. • Dosage regimens cannot be based simply on
body weight or surface area of a pediatric
patient extrapolated from adult data.
– Bioavailability, PK, PD, efficacy, and safety
information can differ markedly between pediatric
and adult patients, and among in pediatric patient
– Differences in age, organ function, and disease
state
– Few such studies have correlated pharmacokinetics
with the outcomes of efficacy, adverse effects, or
quality of life.
22
Dosage
40. • Concordance and adherence of parents or
caregivers must be considered.
• Non-adherence
• General principles to improve adherence
– Fewer medicines
– Formulation (taste, appearance, ease of
administration)
– Simple regimen
– Be involved in choosing suitable preparation if
possible.
40
Medicines optimization
41. Medication Adherence
• Factor affect adherence
– Poor communication between the physician and
patient or parent
– Insufficient prescribing information
– PRN處方應該要把「適應症」、「使用劑量」、「每日最多使用
量」標示清楚
– Lack of understanding about the severity of illness by
the patient or parent
– Lack of interest (eg, among adolescents)
– Fear of side effects
– Failure of the patient or parent to remember to
administer the drugs
– Inconvenient dosage forms or dosing schedules
involving administration of three or more doses daily
– Unpalatability of drug products 41
42. • Policies and guidance of medicines in
schools.
– No legal or contractual duty on school staff to
administer medicine or supervise a pupil
taking it.--→voluntary role
– Policies and procedures are required to ensure
that prescribed medicines are labels, stored
and administered safely and appropriately.
– Teachers and care assistants are adequately
trained and understand their responsibilities.
42
Medicines optimization
43. THANK YOU
謝 謝 聆 聽
高雄醫學大學附設中和紀念醫院
Kaohsiung Medical University Chung-Ho Memorial Hospital
43