Pharma

Question 1

IV: barriers to absorption

Answer 1

none (absorption bypassed)

Question 2

IM: barriers to absorption

Answer 2

capillary wall

Question 3

sub Q: barriers to absorption

Answer 3

capillary wall

Question 4

PO: barriers to absorption

Answer 4

epithelial lining of GI tract: capillary wall

Question 5

disadvantages to IV

Answer 5

• irreversible
• expensive
• inconvenient
• difficult
• risk of: fluid overload, infection, embolism
• drug must be water soluble

Question 6

disadvantages to IM and subQ

Answer 6

• discomfort
• inconvenient
• potential injury

Question 7

disadvantages to PO

Answer 7

• variability
• inactivation by gastric acid and digestive enzymes
• possible n+v from local irritation
• patient must be conscious + cooperative

Question 8

factors affecting absorption

Answer 8

• rate of dissolution
• surface area
• blood flow
• lipid solubility
• pH partitioning

Question 9

factors affecting distribution

Answer 9

• blood flow to tissue
• ability of drug to enter vascular tissue
• ability of drug to enter cells

Question 10

define drug distribution

Answer 10

drug movement from the blood to the interstitial space and then into the cells

Question 11

factors affecting metabolism

Answer 11

• age
• induction & inhibition of drug metabolizing enzymes (increase rate of metabolism, accelerate metabolism of other drugs)
• first-pass effect
• nutritional status (ex. malnourished)
• competition between drugs

Question 12

3 steps for excretion

Answer 12

• glomerular filtration
• passive reabsorption
• active secretion

Question 13

factors that affect excretion

Answer 13

• pH dependent ionization
• competition for active tubular transport
• age

Question 14

minimum effective concentration

Answer 14

a level a drug must be at or above to be effective

Question 15

toxic concentration

Answer 15

too much drug is in the system

Question 16

peak concentration

Answer 16

time for the drug to reach it’s maximum response

Question 17

trough concentration

Answer 17

lowest level of concentration: must be kept above this to have a therapeutic effect

Question 18

loading dose

Answer 18

a high amount of the drug given once or twice to “prime” the blood stream with a level sufficient to induce a therapeutic response

Question 19

maintenance dose

Answer 19

dose given before plasma levels drop back towards zero in order to keep the plasma drug levels in a therapeutic range

Question 20

maximal efficacy

Answer 20

the largest effect a drug can produce

Question 21

relative potency

Answer 21

the amount of the drug we must give to elicit an effect

Question 22

agonists

Answer 22

bind and activate receptors - mimic the bodies own endogenous regulatory molecules

Question 23

antagonists

Answer 23

prevent receptor activation (turns it off)

ex. narcan

Question 24

ED50

Answer 24

average effective dose - standard dose

dose required to produce a defined response in 50% of the population

Question 25

therapeutic index

Answer 25

measurement of drug safety - ration between lethal dose and effective dose larger therapeutic index is safer

Question 26

what are the possible consequences of drug-drug interactions

Answer 26

- intensify therapeutic/adverse affects - reduce therapeutic/adverse affects - create a unique response

Question 27

what is the role of the CYP450 enzymes

Answer 27

they catalyze drug metabolism