Advanced Principles Of Science Flashcards
What are the different stages of life
Neonate 37-42 weeks
Infant 4 weeks - 12 months
Child 1-12 years
Adolescent 12-17 years
Young adults 18- mid 20’s
Middle Ages 40-60
Older people >65
Differentiate between IV bolus and IV infusion
Bolus - drug administrated into vein over a short period of time 1-2 minutes
IV - infusion fluid administered over a long period of time >30 mins
Why might you need to change the formulation of a drug
Oral route causes too many side effects
Dysphagia
Nil by mouth
What are serious ADRs classified by the MHRA
Death
Life threatening
Hospitalisation
In capability or disability
What are the 5 types of ADR
A- augmented, exaggerations at normal dose (dose dependent)
B - bizarre reactions, not expected (e.g., anaphylaxis with penicillin)
C - continuing reactions - persistent for a long time ( oesreonecrosis of the jay with bisphosphonates)
D - delayed reactions
E- end of use, associated with withdrawal
What is NTRO
N - nature of symptoms
T - timing of symptoms and period from when treatment was started
R- relationship of dose
O - other medication, could manifest due to underlying medication
Drug absorption in neonates
Erratic absorption in newborns and unavailable in I’ll babies as they’re stomach doesn’t empty fully. IV or rectal are the best routes
Drug distribution in neonates
Hydrophilic distribute in water and lipophilic distribute into fat
Increases percentage body water and ratio of intra to extracellular fluid
Amount of albumin compared to free drug conc
Less albumin so more free drug in the plasma
Drug metabolism is neonates
Not too different from children
Hyperbilirubinaemia in newborns affect metabolism
Immature metabolic pathway
Drug elimination in neonates
Immature hepatic and renal function
Low elimination
Drug absorption in children
Same as healthy adults
IM is faster because they have increased muscle flow
Drug distribution in children
Larger doses are required as % body weight, body water and extracellular fluid decrease with age
Drug metabolism in children
Between 1 and 9 drug metabolism is higher than adults
Higher doses are given
Drug excretion in children
Maturity of glomerulus is 12-18 months
After 18 months renal excretion is that of an adults
Drug absorption in elderly
Delay of gastric emptying
Reduction in splanchnic output and gastric acid output
Slower digoxin absorption but rest is the same as an adult
Drug distribution in elderly
Reduced lean muscle mass
Total body water
Total body fat
Serum albumin level
Increased Vd for fat soluble compounds but reduced Vd for water soluble compounds
Drug metabolism in elderly
Impaired first pass metabolism
Hypotension effects of nifedipine is increased
Drug excretion in elderly
Glomerular filtration declines as does renal plasma flow
Lower doses of drugs with lower therapeutic index
What is a pharmacokinetic interaction
Patient taking one drug alters the pharmacokinetic of another
Increases / reduces amount of drug available
What are pharmacodynamic interactions
Different drugs having similar or antagonistic pharmacology
Could be competition at receptor sites
What are the 3 mechanisms for absorption interactions
Changes in GI pH
Absorption and chelation (TCAs chelating with metallic ions - poor absorption)
Changes in GI motility
What are the 2 main mechanisms for metabolism reactions
Phase 1 reactions - oxidation, reduction or hydrolysis
Phase 2 reactions - drugs / phase 1 metabolite are conjugated with another substance to make metabolites
What are the 2 most important isoenzymes of CYP
CYP3A4
CYP2D6
