Zusammenfassung
Kinder sind in der Anästhesie eine seltene Patientengruppe. Um Medikamentenfehldosierungen
zu vermeiden, sind genaue Kenntnisse über Aufnahme, Verteilung, Verstoffwechselung
und Ausscheidung der verwendeten Wirkstoffe wesentlich. Auch bedarf es ausreichender
Erfahrung mit pharmakokinetischen Variationen oder Komedikationen innerhalb der verschiedenen
Altersklassen, um patientenadaptiert eine korrekte Dosisapplikation zu ermöglichen.
Abstract
Under- or overdosage of medication can lead to severe side effects in children. To
avoid this, precise knowledge of age-specific liberation, absorption, distribution,
metabolism and excretion – LADME for short – is necessary. Absorption can take place
intravenously, orally, rectally, intranasally, transdermally or epidurally/caudally
and is associated with numerous special features in children, depending on age and
route of application. The distribution in children is faster due to more permeable
organ barriers between individual organs and must be adapted for hydrophilic and lipophilic
drugs to the patientʼs age as well as their fat and fat-free body parts. Drug biotransformation
takes place through Phase I and Phase II reactions, predominantly in the liver and
kidneys. The cytochrome P450 (CYP450) enzyme system is the most important system for
this and requires dose adjustment for numerous drugs in the first phase of life. Due
to immature kidney function, all drugs with high renal clearance have a prolonged
duration of action in the first months of life. Biliary excretion is particularly
important for substances with a molecular weight of > 500 g/mol and is of limited
functionality during the first months of life. The amount of substrate that is eliminated
by the liver and kidneys within a defined period of time is known as clearance and
is strongly dependent on the substance and age of the child. Reciprocal to this is
the elimination half-life, which has to be considered especially with repetitive administration.
Only with sufficient experience with pharmacokinetic variations or comedications within
the different age groups, a patient-adapted, individually correct dose application
is possible. The knowledge of the age-specific pharmacokinetics together with the
knowledge of patient-specific peculiarities and comedications allow an individual
drug application characterized by heuristics.
Schlüsselwörter
Kinderanästhesie - Medikamentendosierung - Pharmakokinetik - Verstoffwechselung
Key words
pediatric anesthesia - drug dosage - pharmacokinetics - metabolism
