week 12 pharmacokinetics

Question 1

how does the body deal with drugs

Answer 1

1. absorption - how a drug gets into the body
2. distribution - how a drug moves around the body
3. metabolism - how the drug is changed in the body
4. excretion - how the drug is removed from the body

Question 2

what are enteral routes of administration of drugs

Answer 2

oral or rectal

- absorption through GI tract

Question 3

what are 2 advantages and disadvantages of oral meds

Answer 3

A
- convenient
- 75% absorbed in 1-3 hrs
D
- food can delay the effect  of absorption 
much slower absorption

Question 4

what are 2 advantages and disadvantages of RECTAL meds

Answer 4

A
- reduces vomiting and nausea 
good when the patient is unconscious and/ seizures
D
- inconvenient 
absorption often incomplete

Question 5

what are 2 advantages and disadvantages of needing meds

Answer 5

A
- rapid onset
- drugs are not broken down by acid/enzymes as in gut
D
- less convenient (skilled person Required)
- risk of infection

Question 6

why does the liver effect digestion of metabolising drugs

Answer 6

drugs that are absorbed from the gut reach the liver via the hepatic portal vein
some drugs have poor bioavailability/distribution due to first pass effect, therefore, can effect metabolisation of certain drugs

Question 7

what are 4 advantages and disadvantages of sub-lingual meds

Answer 7

A

• good vascularisation
• rapid absorption into blood stream
• absorb rapidly
• straight to heart

Question 8

what are 3 advantages and disadvantages of topical meds

Answer 8

A

• skin patches
• local effect
• direct application to the injured site

Question 9

what are the sites of absorption

Answer 9

lungs
GI tract
skin

Question 10

what is the purpose of metabolism

Answer 10

• increase the rate of excretion
• reduce its toxicity
• more polar
• less pharmacological activity

Question 11

how does the body enzymes process drug molecules

Answer 11

• they enzymatically process the drug molecules using the same pathway as natural compounds
• with this, the drug may have its action increased or decreased during metabolism

Question 12

what are the two major enzymatic reactions and categories

Answer 12

phase 1 reactions 
- oxidations (cytochrome P450)
- reduction (reductases)
- hydrolysis (esterases)
phase 2 reactions - add the water-soluble product to drug
- glucuronide
- glutathione 
- sulphate
- acetate

Question 13

what are the 4 factors affecting drug metabolism

Answer 13

genetics
age
gender
other drugs that are being taken

Question 14

how can it be an issue if you are taking many drugs that are processed and metabolised by the same enzyme?

Answer 14

this can decrease the rate of metabolism as the drug is relying on the same enzyme to break the drug

Question 15

is an intramuscluar injection of a drug faster for patient than intravenous injection

Answer 15

no

Question 16

are active transport mechanism is responsible for most aspects of drugs distribution in the body

Answer 16

no, passive diffusion is

Question 17

is oxidation of drugs in the body usually carried out by hepatic microsomal enzymes

Answer 17

true cytochrome P450

Question 18

does drug metabolism occur predominately in the liver

Answer 18

true

Question 19

does Phase 1 include hydrolysis and oxidation

Answer 19

true plus reduction

Question 20

it is important to know when adding more drugs to the treatment of a patient?

Answer 20

true

Question 21

how might patients modify their drug dosage if they have problems with there liver and why

Answer 21

not going to metabolise drugs normally in drugs in phase 1 and 2, therefore, they are at toxicity meaning they need to lower the dosage