Drug Absorption Flashcards
Pharmaceutical process
get the drug into the patient
Pharmacokinetic process
get the drug to the site action
Pharmacodynamic process
produce the correct pharmacological effect
Therapeutic process
produce the correct therapeutic effect
What are the 4 basic factors that determine drug pharmacokinetics?
- absorption
- distribution
- metabolism
- elimination
What does ADME enable us to understand?
- dosage
- drug administration
- drug handling
- patient variability
- potential for harm
Absorption
- the process of movement of unchanged drug from the site of administration to the systemic circulation
- there is always a correlation between plasma concentration of a drug and the therapeutic response
How can drugs be absorbed?
- oral
- IV
- IM
- other GI- sublingual, rectal
- inhalation
- nasal
- transdermal
What are important issues to consider with oral absorption?
- amount of drug which enters the systemic circulation
- speed at which this happens
What is Tmax?
- the time to peak concentration
- the more rapid the rate of absorption, the earlier the drug concentration peak
What is Cmax?
- peak concentration
- increasing dose does not affect the time at which peak concentration is reached but does increase peak concentration
What is AUC?
-are under the drug concentration time curve represents the amount of drug which reaches the systemic circulation
Therapeutic range
a drug is active over a range of concentrations
What happens outwith the therapeutic range?
- below this there will insufficient or no pharmacological action
- above this toxicity occurs
Therapeutic index
a measure of the range at which a drug is safe and active