Brainscape's Knowledge GenomeTM

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


See full index

Manchester Year 1 > Pharmacology Lecture 2 > Flashcards

Pharmacology Lecture 2 Flashcards

Metabolism and Excretion

1
Q

Define Clearance (Cl)

A

The volume of plasma completely cleared of drug per unit time.

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

What does Cp represent?

A

The concentration of drug plasma

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

Rate of Elimination equation

A

Rate of elimination = Cl x Cp

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

Where can metabolism occur in the body?

A
  • The liver is the main organ for drug metabolism

- Metabolism also occurs in the gut, lungs, skin, blood and kidney

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

Describe the general process of metabolism?

A

Metabolism changes one chemical compound into another

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are the 2 phases of metabolism?

A

Phase 1: catalysed by cytochrome P450 enzymes. Often still chemically active.

Phase 2: Conjugation by adding a glutathione, methyl or acetyl group. More water soluble and easier to excrete. Less active or inactive.

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

What are hepatocytes?

A

Hepatocytes are the chief functional cells of the liver that contain enzymes essential for metabolism.

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

Define Metabolite

A

A drug metabolite is a byproduct of the body breaking down, or “metabolizing,” a drug into a different substance.

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

Define first pass metabolism

A 
If a drug is extensively metabolised in the liver we say it undergoes first pass metabolism – 
Very little (active) drug may end up in the systemic circulation.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Pathway of absorption of oral drugs

A

GI Tract
Liver
Heart
Systematic Circulation

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

Name 2 routes that avoid first pass metabolism

A

Sublingual
Buccal
(Because blood supply from the mouth goes to the heart first - avoids the liver)

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

What are the 2 classes of tests for hepatic (liver) function in pracice?

A

Serum tests

Urine tests

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

What is LFT an abbrev for?

A

Liver Function Tests

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Define excretion

A

The process by which waste products are removed from body.

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

Where can excretion occur in the body?

A

Predominantly by kidney via urine

Also via bile, sweat, faeces, breath, and tears.

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

Are all drugs metabolised before exrcretion?

A

No.

e.g. aminoglycoside antibiotics

17
Q

Name the 3 processes by which the kidney excretes drugs.

A
  1. Glomerular filtration
  2. Tubular secretion
  3. Tubular reabsorption
18
Q

Define/describe a nephron

A

A functional unit of the kidney, the structure that actually produces urine in the process of removing waste and excess substances from the blood. There are about 1,000,000 nephrons in each human kidney.

19
Q

Describe Glomerular filtration

A 
Small drugs pass easily from blood through glomeruli.
Large drugs (e.g. Heparins and protein bound drugs) cannot pass through.
20
Q

Describe Tubular Secretion

A

An active process against a chemical gradient. There are

2 Carrier transport systems; basic drugs (amiloride) and acidic drugs (furosemide)

21
Q

Describe Tubular reabsorption

A

Transported back into the blood along with water to maintain fluid volume.
(Some of the small molecules will pass back into the blood stream)

22
Q

Define renal clearance

A

The renal clearance of any substance is the volume of plasma containing that amount of the substance that is removed by the kidney in unit time

It is the amount of drug removed by kidney over specific time. Varies for different drugs.

23
Q

Name a (estimated) measure of renal function

A

Creatinine clearance
or
E-GFR

24
Q

State the Cockcroft and Gault equation used for calculating creatinine clearance.

A 
CrCl (ml/min) = 
F x (140-age) (weight kg)  / serum creatinine (micromol/L)

Where F = 1.23 (males) and (1.04 females)

NB that CC is an ESTIMATION of renal function.

25
Q

What does E-GFR stand for and what is it for?

A

Estimated glomerular filtration rate

Another (better/more accurate) means of estimating renal function, and uses race.

26
Q

What is the biliary system? What process is it a part of: Metabolism or excretion?

A

The biliary system consists of the organs and ducts (bile ducts, gallbladder, and associated structures) that are involved in the production and transportation of bile.

Excretion

27
Q

Examples of some processes that can occur in Phase 1 of metabolism?

A

Oxidation
Hydrolysis
Reduction

28
Q

Can drugs undergo Phase 2 only of metabolism (i.e. without phase 1)?

A

Yes

I don’t think Phase 2 and then Phase 1 can happen though

29
Q

What is a pro-drug?

A

a biologically inactive compound which can be metabolized in the body to produce a drug.

30
Q

What does hepatic function mean?

A

Liver function

31
Q

What makes a drug more likely to just be excreted and not metabolised?

A

If it is highly soluble

32
Q

What is creatinine?

A

Creatinine is a chemical waste product of creatine (normal breakdown product), released from muscle breakdown, and undergoes glomerular filtration. Creatinine is removed by the body entirely by the kidneys

33
Q

What does renal function mean?

A

Kidney function

Manchester Year 1 (9 decks)

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