Pharmacology Flashcards
What are unlicensed/ off label medications?
- Formulation administered via a route not intended
- Medicines used for an indication not intended
- Medicines used at a different dose to that recommended
- Children below stated recommended age limit
- Medicines without a licence, including those being used in clinical trials
How often are unlicensed drugs used in children?
In hospitals
- 60-90% are off-label
- 10-50% are off label
Consequences of using unlicensed drugs?
- Altered pharmacodynamic responses
- Effects on growth ad development
- Pharmacokinetic response different between adults and children
Considerations
- Neonates are more sensitive to drugs than adults
- Neonates are at increased risk for ADRs
- younger patients show greater individual variation
Pharmacology in the early post-natal period?
- Rapid growth
- Variable alteration in metabolism and elimination
- Lower tolerance to ADRs
- Difficulty in efficacy and toxicity
What is one of the main problems with pharmacology in toddlers?
COMPLICANCE
What affects absorption in neonates
Decrease gastric emptying and motility
What affects distrubution in neonates
Body composition:
- Higher Extracellular fluid
- Total body weight
- Fat content is low
Plasma protein binding is reduced so more unbound active drug
BBB- not fully developed at birth so more chance of CNS toxicity
What affects drug metabolism
Hepatic function
- Liver metabolism is immature
- Immaturity of drug metabolism
- Oxidation and glucorinidation are reduced
What affects drug elimination
- Renal excretion
- Less glomerular filtration
- Less tubular function
At what age is adult renal/ tubular function acquire in children?
Renal: 3-6 months
Tubular: 12 months
What happens for most drugs at 12 months
T1/2 is increased
At what stage does child presentation begin to appear like child presentation?
In children: 2 yrs to 11 yrs
