Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Alan's lecture - Pharmacology > Dose adjustment > Flashcards

Dose adjustment Flashcards

1
Q

Where do recommended dose of drugs derive from?

A

Clinical trial data of patient population

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is pharmacogenetics?

A

It is the effect of genetic factors on reactions to drugs.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

The genetic differences affect the pharmacokinetics of a drug in a particular patient. TRUE OR FALSE?

A

TRUE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are the factors that can lead to a change in dose?

A
  1. Age
  2. Hepatic disease
  3. Renal impairment
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

In terms of age, how does absorption compare to children and the elderly?

A

Children

  • Gastric emptying is slower
  • Peristalsis is less regular (affects transit time)

Elderly

  • Delayed gastric emptying
  • Elevated gastric pH
  • Reduced peristalsis
  • Active transport may be decreased
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Children can absorb drugs faster and more compared to adults. TRUE OR FALSE?

A

TRUE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

If active transport is decreased, does this also decrease the bio-availability of the drug? TRUE OR FALSE?

A

TRUE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

If pH is elevated the bioavailability of drug may increase. TRUE OR FALSE?

A

TRUE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Volume distribution does not increase with age. TRUE OR FALSE?

A

FALSE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Binding to plasma protein may be decreased in very young. TRUE OR FALSE?

A

TRUE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

In the elderly, altered body composition may change distribution i.e change in adipose tissue, muscle mass. TRUE OR FALSE?

A

TRUE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Change in distribution of drug may affect how much of the drug is available in the systemic circulation. TRUE OR FALSE?

A

TRUE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are the factors that can affect drug distribution in the elderly?

A
  • Altered body composition
  • Reduce cardiac output
  • Increased peripheral resistance
  • BBB permeability may increase
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Drug metabolic ability increases from birth to 6 months . TRUE OR FALSE?

A

TRUE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

P450 metabolism increases with age. TRUE OR FALSE?

A

FALSE, it decreases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

In the elderly there is a increased hepatic blood flow. TRUE OR FALSE?

A

FALSE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

GFR decreases with age but can be very variable, which can lead to higher exposure so increased chances of toxicity. TRUE OR FALSE?

A

TRUE

18
Q

In hepatic disease is there an increase or decrease in metabolism of CYP450 for example?

A

There is a reduction in metabolism, but it is not inevitable and depends on the nature of liver disease

19
Q

What is cirrhosis and viral hepatitis and their impacts on drug metabolism?

A

Cirrhosis - Part of the liver tissue is replaced by scar tissue, it is possible that metabolism may be reduced due to scar tissue

Viral hepatitis - Inflammation of the liver, with this it is less likely that metabolism will be reduced

20
Q

What is the major site where serum album is synthesised?

A

The liver

21
Q

Some drugs do not undergo extensive hepatic metabolism, so giving a patient with hepatic disease drugs that do not under go extensive hepatic metabolism should not really impact the therapeutic effect of the drug. TRUE PR FALSE?

A

TRUE

22
Q

In terms of hepatic disease; Half life may not decrease due to decreased albumin, which leads to an increase in volume distribution. TRUE OR FALSE?

A

TRUE

23
Q

Reduced first pass effect may increase bioavailability. TRUE OR FALSE?

A

TRUE

24
Q

How does protein binding affect drugs which are extensively bound to albumin?

A

Drugs which are extensively bound to albumin are more likely to be affected by hepatic disease

25
Q

A decrease in albumin would cause an increase in drug unbound, what effects may this cause?

A
  • Increase therapeutic effect
  • Increased toxicity
  • Change in distribution Vd which may cause unexpected toxicity
26
Q

What is hepatic encephalopathy and which drugs are a major concern for this, give example?

A

This is impaired brain function which is particular concern with drugs known to have effect on the CNS
e.g sedatives, opioids

27
Q

Which types of drugs cause fluid retention?

A

NSAIDS

28
Q

What is hepatoxicity and which drugs are a major concern for this?

A

Liver toxicity is particular concern with drugs that are intrinsically hepatoxic (self perpetuating)

29
Q

What are the consequences of having reduced renal function?

A
  • decreased GFR
  • Reduced clearance - higher plasma levels are possible
  • Longer half life/ time to reach constant steady state is increased
30
Q

Hoe can renal function be estimated?

A

By measuring creatine clearance as surrogate to estimate GFR

31
Q

Where is creatinine produce?

A

In the muscles

32
Q

How is Creatinine eliminated?

A

Eliminated largely by Glomerular Filtration

33
Q

Creatinine clearance is aprox GFR. TRUE PR FALSE?

A

TRUE

34
Q

Creatinine serum can be used to estimate GFR and results obtained is creatinine clearance. TRUE OR FALSE?

A

TRUE

35
Q

Creatinine is not produced at a constant rate by muscles. TRUE OR FALSE?

A

FALSE

36
Q

Which two equations can be used to estimate GFR?

A
  • Cockroft gault equation

- MDRD method

37
Q

Which of the equations is considered to be more accurate? Cockroft gault equation
-MDRD method

A

MDRD method - normalized to body surface area

38
Q

What are the limitations to estimating GFR using these two equations/

A
  • Average muscle mass appropriate to patient’s age, height and age
  • May be inaccurate if poor nutrional state, highly muscular, obese and extremes i.e GFR too high or too low, limb amputation, extremes of age
39
Q

Some creatinine is excreted by tubular secretion so creatinine clearance may be slightly greater than GFR . TRUE OR FALSE?

A

TRUE

40
Q

What is a more accurate way of measuring creatinine clearance and give its disadvantages?

A

By measuring creatinine excreted in urine over 24hr
Disds:
-more accurate than inconvenient
-need to collect urine over 24hr and measure volume
-Incomplete collection
-need to measure creatinine in serum and urine

41
Q

As patients get older renal function decreases, so creatinine clearance decreases and varies between men and women. TRUE OR FALSE?

A

TRUE

Alan's lecture - Pharmacology (16 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions