Pharmacokinetics/Dynamics EXAM REVIEW Flashcards

1
Q

What is the definition of oxidation?

A

Loss of electrons; phase I reaction

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

What is reduction?

A

Gain of electrons: Phase I reaction

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

What is Hoffman degradation?

A

Example of non-organ metabolism

Site of metabolism is PLASMA

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

What is Hydrolysis ?

A

Splitting molecule with the addition of water/ PHASE I

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

What is the relationship between ph and pKa.

A

When pH=pKa, 50% of the drug is ionized and 50% in non- ionized.
Lower pKa stronger acid, Higher pKa stronger base.

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

How does ph and pKa relationship affect weak bases and weak acids?

A
  • A general rule with weak bases states when the pKa minus pH < 0, then most of the drug will be in the non-ionized form.
  • With weak acids the opposite is true. pKa minus pH < 0 then most of the drug will be in the ionized form.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What percentage of cardiac output is distributed to each tissue compartment?

A

HIGHLY PERFUSED (lungs, heart, brain, kidneys, liver) ~ 75%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q
  1. Explain when protein binding becomes a concern to the clinician?
  2. Protein binding and Vd
  3. Protein binding and metabolism
  4. Protein binding and lipid solubility
  5. when is alteration important
A
  1. Protein binding effects Vd because only
    unbound drug can cross cell membranes.
    Therefore the Vd is inversely related to
    protein binding.
  2. Only unbound drug can undergo
    metabolism and glomerular filtration
  3. Extent of protein binding directly related to
    the lipid solubility
  4. Alterations in protein binding are only
    important for drugs that are highly
    protein bound.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q
  1. What are methods of metabolism? What are considered to be phase 1? What are considered to be phase 2
A

Phase 1 (ORH)
Oxidation, reduction and hydrolysis are
Phase II reaction –> CONJUGATION

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

6.Which routes of drug administration undergo hepatic first pass effect? Which do not?

A

1.Drugs that undergo large first pass hepatic
effect (lidocaine, propranolol) PO and IV doses very different
2. AVOID first pass effect
Include sublingual, buccal and nasal route, IV
3. Drugs administered into to LOWER RECTUM avoid the first pass effect

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q
  1. What drug characteristics will affect Vd?
A

Lipid solubility, protein binding, molecular
size.
• Drug with LOW LIPID SOLUBILITY and HIGH PROTEIN BINDING will have a LOW Vd

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

Vd is _______to protein binding

A

Inversely proportional

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q
  1. Define zero order kinetics?
    Definition
    When does it occur?
    Result of
A

A constant amount of drug in cleared per unit of time regardless of plasma concentration
Occurs when the plasma concentration of
drug exceeds the capacity of metabolizing
enzymes.
• Result of saturating the available enzymes
at high drug concentrations of some
compounds.

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

What drugs undergo zero order kinetics?

A

Alcohol, Aspirin, and Phenytoin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q
  1. Define first order kinetics? What drugs undergo first order kinetics?
A

Most drugs will follow linear of first-order
kinetics.
• Constant fraction of drug is metabolized
per unit of time.

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

In first order kinetics the metabolism of a drug is highest when?

A

when the drug concentration is greatest.

17
Q

In first order kinetic; The fraction of drug eliminated is_________

A

independent of the drug concentration

18
Q

For first order kinetic, It will take 1 half-life for the plasma________
At 5 half-lives the drug plasma
concentration declines by_______

A

concentration to decline by 50%.

96.9 %

19
Q
  1. What are the mechanism for renal excretion of drugs? (3)
A

Glomerular filtration.
Passive tubular secretion.
Passive tubular reabsorption.

20
Q
  1. What organ is responsible for drug metabolism
A

Liver

plasma for hoffman degradation

21
Q
  1. Why do the elderly respond to drugs differently than younger patients? (DED-DI)
    They all lead to ________and _________
A

Decreased cardiac output
Enlarged fat content
Decreased protein binding
Decreased renal function

all lead to drug accumulation and increased risk of toxicity

22
Q
  1. What is the principal effect of metabolism?
A

The role of metabolism is to convert
pharmacologically active, lipid-soluble drugs
into water soluble inactive compounds that
can be easily excreted.

23
Q

14a Define Enantiomer?

A

A pair of molecules existing in two forms
that are mirror images of one another but
cannot be superimposed. All contain a chiral carbon

24
Q

Define stereoisomer

A

are a particular kind of isomer that are different from each other only in the way the atoms are oriented in space (but are like one another with respect to which atoms are joined to which other atoms)

25
Q

Define Chiral Carbon

A

Chiral is a term used to describe a molecule

that has a center (or centers) of threedimensional asymmetry

26
Q

Enzyme inducers drugs RPPCAC

A
Rifampin
Phenobarbital
Phenytoin,
cigarette smoking
Alcohol Chronic
carbamazepine.
27
Q

Enzyme Inhibitors drugs are

ProDiVE - CANVA

A
Protease inhibitors
DI- ltiazem
Verapamil
Erythromycin
Cimetidine
Acute alcohol ingestion
Nefazodone
Valproic acid
Amiodarone
28
Q
  1. What affect will ionization, molecular size, lipid solubility, protein binding have on Vd?
A

the NON-IONIZED portion of the drug is more lipid soluble and therefore crosses the cell membrane better (higher Vd)
HIGHER IONIZED –> Lower Vd
Molecular size: higher molecular weight, low Vd
Lower molecular size: HIGH Vd
Therefore the Vd is INVERSELY related to
protein binding.
Low lipid solubility + high protein binding–>low Vd(locked in vessels)
High lipid solubility + low protein binding –> High Vd (distributes easily)

29
Q
  1. Define pharmacokinetic.
A

The quantitative study of absorption, distribution, metabolism, and excretion of drugs and their metabolites
The movement of a drug through the body
over time.
“What the body does to a drug

30
Q

Define pharmacodynamics.

A

The study of the intrinsic sensitivity of
responsiveness of receptors to a drug and
the mechanism by which these effects
occur.
“What the drug does to the body”

31
Q
  1. Weak BASE given pKa and ph when will non-ionized or ionized from (general rule)
A

A general rule with WEAK BASES states when the pKa - pH < 0, then most of the drug will be in the NON-IONIZED form.

32
Q

Weak ACID given pKa and ph when will non-ionized or ionized from (general rule)

A

With weak acids the opposite is true. pKa minus pH < 0 then most of the drug will be in the ionized form

33
Q
  1. Understand the principles behind calculating a creatinine clearance.
A

•{140 - age ) x IBW /72 x Serum creatinine} x (0.85 for females.)
Formula used to calculate estimated creatinine clearance.
• IBW male 50 +(2.3 x each inch
>60) IBW in Kg
• IBW female 45.5 + (2.3 x each
inch >60) = IBW in Kg

34
Q

Define drug clearance.

A

The volume of plasma cleared of drug by renal excretion and/or metabolism by the liver or other organs

35
Q

Anaphylaxis

A

antigen-antibody interaction,

immune mediated and REQUIRES PRIOR EXPOSURE

36
Q

Anaphylactoid

A

no previous exposure or sensitization, not a true allergic reaction but results in histamine release, vasodilation, wheals, and welts