Prescribing Flashcards
What does pharmacokinetics look at?
Drug disposition - absorption, distribution, metabolism and excretion
7 ways absorption from GI tract is effected in infants?
gastric pH is elevated till around 3 months, peristalsis is slower, enzyme activity effected, mucosal membrane permeability, flora, biliary function, dietary components
What happens to basic and acidic drug absorption in infants?
Increased basic absorption due to increase gastric ph and decreased acidic absorption
What is the main factor effecting distribution in neonates and how does this change over time?
Body composition, initially 85% pre term, 75% full term, 55% age 12
How does ECF volume change over time?
Premature 50%, full term 45%, adult 25%
Difference in metabolism of drugs in infants? which 2 drugs are unique to this rule?
Less mature liver enzymes therefore slower metabolism although theophylline and AEDs are metabolised quicker
Excretion differences in neonates? examples of drugs that are effected by a changed excretion time?
Increased excretion time due to decreased maturity of renal tracts, ampicillin, furosemide, gentamicin
How do you calculate dose in overweight children?
height and age, not weight
What do you need to know about a drug before you prescribe it safely to a neonate?
What is the drug, what is it used for, what formulation will it be given in, what concentration and volume is required, does the neonate have any preexisting conditions that may contraindicate its use, any medications that will interact
What do you need to prescribe liquids in terms of?
Their strength not their ml
What should you write instead of 0.1mg
100micrograms
When medicine is prescribed as required, what must be specified?
Minimal dose interval
What factors can effect whether a child takes a medication?
Look, taste, ease of administration, frequency, do they have to take it to school
