consolidation

Question 1

Which of the following processes are part of pharmacokinetics?

a. Absorption
b. Distribution
c. Metabolism
d. Excretion
e. All of the above

Answer 1

e. all of the above

Question 2

A patient who sustained a fracture of the proximal humerus is in severe pain. As the attending doctor, you want to prescribe a most appropriate drug alleviate her pain as fast as possible. Which of the following elements of pharmacokinetics do you think are most relevant to consider related to this goal?

a. Absorption and distribution
b. metabolism and excretion
c. absorption and excretion
d. metabolism only

Answer 2

a. absorption and distribution

Question 3

Which of the following is likely to be the best ‘measure’ of when the patient attains effective pain relief?

a. when the drug is first detectable in the plasma
b. when the drug reaches therapeutic levels in the plasma
c. When the drug exceeds therapeutic levels in the plasma
d. when metabolites of the drug are detected in the urine

Answer 3

b. when the drug reaches therapeutic levels in the plasma

Question 4

What be the route of administration that would reach peak plasma concentrations the fastest?

Answer 4

Intravenous

• no absorption, straight goes into the blood vessels

intramuscular , has to go through the muscle

Question 5

Why not all medication are given through Intravenous?

Answer 5

puncture of vein high possibility without canular

• not easy to cannulate
• usually in hospital or under care of a medical professional

Question 6

Ibuprofen, a commonly used NSAID, is rapidly and completely absorbed following oral administration. It has a half life of about 2 hours and unbound concentrations show linear pharmacokinetics at commonly used doses. Assuming it is given at regular intervals, approximately how long would it take for ibuprofen to reach a steady state?

a) 8-10 hrs
b) 2-3 hrs
c) 12-15 hrs

Answer 6

a) 8-10 hrs

4-5 half lifes to take a drug to reach a steady state concentration.

Xo + 1/2Xo , “”+ 1

every time a drug is added

not a desperate rush to reach the therapeutic rate

loading dose, straight away get to the therapeutic levels,
loading dose = Vd x target Cp

Question 7

Which of the following is FALSE regarding factors influencing clearance of a drug?

a. hepatic function
b. renal function
c. vol of distribution
d. allergic reaction to the drug

Answer 7

d. allergic reaction to the drug

vol of distribution , if distributed easier to clear from the kidney

free drug
protein bound

Question 8

Is there a disadvantage or adverse effects of giving loading dose instead of interval doses for chronic diseases?

Answer 8

IV, you do not want to do that unnecessarily
must be careful when using high dose
high risk of human error occurs

only used for

• pain
• seizures etc.

not commonly done , usually allow body to get used to the therapeutic state

Question 9

Many drugs are cleared via a renal route. Which do you think would be TRUE if a patient with renal failure is given a drug that is cleared via the renal system?

a. the half life would be reduced
b. the drug would be cleared more rapidly
c. the patient should be given more frequent dosing of the drug
d. the risk of reaching toxic levels of the drug is increased

Answer 9

d. the risk of reaching toxic levels of the drug is increased

nothing to do with half life, more towards clearance point of view

• ability of renal system is compromised , the clearance will be affected
• different method to monitoring drug for renal failure
  more towards what dose or how much and understand how metabolism is taking place in patient

must adjust dose
- will not give same dose as a normal patient

Question 10

You are a medical student doing an attachment in a GP clinic. A patient comes to the clinic complaining of pain following a fall. You ask several questions about the mechanism of the injury. Why is this important?

Answer 10

it gives valuable clues about the most likely injuries to look out for

Question 11

Mrs Chan, a 70 year old lady has a fall in the bathroom and lands on her outstretched right arm. Following this she has severe pain over the right shoulder and is unable to move the arm. Can you try to list some structures that could have been injured in this fall?

Answer 11

distal radius fracture 
midshaft of the humerus 
humerus neck 
scaphoid 
but shoulder pain 

so, it should be around the proximal humerus

Question 12

This is the X ray for Mrs Chan. What does this X ray show?

a. dislocation
b. fracture neck of the humerus
c. clavicle fracture
d. rotator cuff inflammation

Answer 12

b. fracture neck of the humerus

Question 13

If a patient with fracture neck of humerus is unable to abduct the arm, which muscle is most likely involved?

a. supraspinatus
b. infraspinatus
c. subscapularis
d. teres minor

Answer 13

a. supraspinatus
( abduction)

• deltoid muscles ( usually)
  axillary nerve

Question 14

On examination, Mrs Chan has loss of sensation over the right deltoid. Which nerve is most likely injured?

a. Axillary nerve
b. C5 root
c. Radial nerve
d. Musculocutaneous nerve

Answer 14

a. Axillary nerve
deltoid is the regimental badge - straight forward is axillary nerve

• do not got for dermatomes
  unlikely injure C5 roots because is up to the cervical cords.

Question 15

On examination, Mrs Chan has loss of sensation over the right deltoid. Which nerve is most likely injured?

Answer 15

Intravenous

• good dose and get her to therapeutic level asap

Question 16

Mrs Chan has been given oral Naproxen SR 1000mg and also a dose of IV morphine within the last 3 hours but she is still in pain. What could be your next option?

a. give a second dose of oral Naproxen
b. give additional Naproxen intravenously
c. give more IV morphine
d. give an interscalene block

Answer 16

d. give an interscalene block
( block nerves that transmit pain)

if given another dose, toxic
do not want to exceed therapeutic levels

too much morphine, very potent in the brain and affect breathing and die

Question 17

morphine , why is it not use frequently?

Answer 17

narcotic 
- addicting 
- only as a one off dose 
- terminally ill 
( to get them comfortable)

Question 18

interscalene blocks are at the root level. how will it be affected?

Answer 18

paralyse the hand and stop the sensory function of the whole upperlimb

Question 19

Following a motor vehicle accident, the patient is found fractures over the transverse process of 2 of the cervical vertebrae. His arm is noted to be hanging at his side, internally rotated and pronated. Which nerves supplying the upper limb are most likely to have been damaged?

a. C8-T1
b. C5 -C6
c. C7-C8
d. entire brachial plexus

Answer 19

b. C5 -C6

pronation is functioning , pronation is intact

there is loss of supination and lateral rotators
- radial nerve ( C5- T1, similar as brachial plexus and median nerve ) C8-T1 usually goes to ulnar nerve
there’s unopposed action of pronation and internal rotation

kings pronate beggers supination

supination

• biceps brachii (chief supinator, primer) musculocutaneous ( c5-c6,c7)
• supinator muscle ( secondary supinate forearm)

function of supinator
- supination  

pronation

• quadratus and pronator teres
• median nerve (c5-c8)