Pharmacology

Question 1

What is the calculation for loading dose?

Answer 1

Target concentration x Volume of Distribution

Question 2

What is the maintenance dose calculation for oral medication?

Answer 2

Target concentration x Clearance rate x Dosing interval amount (hours)
/
Bio-availability

Question 3

what is the half life calculation?

Answer 3

0.693 x Volume of Distribution

/

Clearance rate

Question 4

What does a PPI work on in the parietal cell?

Answer 4

H+/ K ATPase

Question 5

What is the CrCl equation?

Answer 5

1.2 x (140 - age) x weight

/

Plasma creatinine

Question 6

How does Gentamicin effect the body in renal impairment?

Answer 6

Reduced filtration - hangs around in body longer

High levels toxic to PCT - necrosis

Question 7

What is the risk in using Biguanides in renal impairment?

Answer 7

Risk of Lactic acid is higher when eGFR falls below <30

Question 8

What is the risk in using Sulphonylureas in renal impairment?

Answer 8

Hypoglyceamia - insulin is metabolised in PCT - so if renal impairment more insulin is already hanging about

Question 9

What is the maintenance dose calculation for oral intake?

Answer 9

Target concentration x Clearance Rate x Dose amount/ interval

/

bio-availability

Question 10

What is the measurement for the previous days deficit (PDD) of fluid?

Answer 10

Measured losses + Insensible losses (800ml) - oral intake

Question 11

How do you calculate the fluid required for the next 24 hours? and what is an important factor to keep in mind?

Answer 11

Measured losses + Insensible losses + Previous days Deficit.

that this doesn’t strictly have to be given over 24 hours in the presence of heart disease etc.

Question 12

When would you give dextrose?

Answer 12

When there has been no electrolyte loss

Question 13

When would you give 0.9% saline?

Answer 13

When there is Na2+ and water depletion

Question 14

What percentage of parietal cells are deactivated with the use of PPIs?

Answer 14

90%

Question 15

Whats the greatest risk of PPI?

Answer 15

Enteric Infection

Question 16

What is the definition of steady state?

Answer 16

When the amount of drug administered is equal to the amount excreted

Question 17

In comparison to enteric route, how much morphine should be given?

Answer 17

1/3rd of the enteric

Question 18

What type of dynamics does Phenytoin have?

Answer 18

Non-linear pharmokinetics

Question 19

Name two peripheral dopa decarboxylase inhibitors

Answer 19

Carbidopa

Benserazide

Question 20

How does methlypheniate work?

Answer 20

Dopamine re-uptake inhibitor - increasing dopamine across the striatum and prefrontal cortex

Question 21

What is Atomoextine’s mechanism of action?

Answer 21

Noradrenaline re-uptake inhibitor

Question 22

Name two Alpha 2 agonists used in ADHD treatment and outline their mechanisms of action

Answer 22

Clonidine

Gaunfaucine

Mimic noradrenaline in the prefrontal cortex by preventing hyper-polarisation allowing more neural firing

Question 23

How does amphetamine work?

Answer 23

Increases dopamine release from vesicles and also prevents re-uptake.

Question 24

What is the drug that blocks Raf kinase and is used in melonoma treatment?

Answer 24

Vemurafenib

Question 25

How much reabsorption does thiazides prevent? and where is this achieved?

Answer 25

5% in the early DCT

Question 26

What are the various receptors a drug can work on? and name some properties of them.

Answer 26

Enzyme linked - multiple actions Ion Channel Linked - speedy action G-protein linked - amplifier Nuclear/ Gene linked - long lasting

Question 27

What is the affinity of a drug?

Answer 27

The propensity to bind to the receptor

Question 28

Which direction will a more potent drug move on the graph?

Answer 28

To the left

Question 29

Which is more potent Morphine or hydromorphine?

Answer 29

Hydromorphine

Question 30

What antobiotic is statins most contraindicated with?

Answer 30

erythromycin

Question 31

In renal disease, what is the main effect on the pharmocokinetics of a drug? and how can this be managed?

Answer 31

Prolonged elimination time - increased half life. increase dosing interval

Question 32

In liver disease, what is the main effect on the pharmocokinetics of the drug? and how can this be managed?

Answer 32

Slower rate of metabolism - increased half life - increased bio- availability increase dosing interval reduce dosage

Question 33

In cystic fibrosis, what is the main effect on the pharmocokinetics of the drug? and how can this be managed?

Answer 33

Decreased elimination and metabolism time. increased volume of distribution increase dosage decrease dosing interval

Question 34

Name some effects renal disease has on drug effects to the body and why:

Answer 34

Pharmokinetics: Decreased elimination Decreased protein binding decreased hepatic metabolism Pharmodynamics: increased sensitivity Adverse effects

Question 35

What two classes of drugs should be avoided in renal impairment?

Answer 35

Metaformin NSAIDs extreme caution with ACE inhibitors

Question 36

In hepatic disease what consideration need to be considered with drug use?

Answer 36

Increased bio-availability reduced albumin binding Increased half life reduced elimination **also important to remember pro-drugs won't work as well.