Pharmacokinetics Flashcards
Define therapeutic range
The concentration of drug in blood plasma which lies betweeen the minimum [toxic] and minimum [therapeutic]
Define Pro-drug
A drug which is activated by first-pass metablism
What is bioavailability?
% of drug that reaches systemic circulation unaltered compared with the total dose administered
What is bioequivalency?
S2 drugs with the same active ingredient with similar rates and extent of effect
What are the 8 routes of administration?
Intravenous Oral Subcutaneous Intramuscular Sub-lingual Intrathecal Transdermal Rectal
Define Volume of distribution
Volume of plasma required to contain the same concentration of drug as that present in the plasma
What is the Vol(dist) for lipid-insoluble and lipid-suluble drugs?
Insoluble - 3.5-14L/kg
Soluble - >40L/kg
Which group of enzymes performs first-pass metabolism?
Cytochrome P450s
What happens in phase 2 metabolism?
Addition of a bulky polar group to the drug to enable renal elimination
How does renal elimination occur?
Blood is filtered in the glomerulus
Nutrients (no-polar) are filtered back into the blood
Urine produced moves to bladder
How many half-lives does it take to contain 10% and 1% of the original dose?
10% - 3 and a bit
1% - 6 and a bit
What is clearance?
Rate of elimination/[plasma] (mg/h)/(mg/l) = L/h
