Pharmacokinetics in Chronic Kidney Disease Patients Flashcards Preview

Renal and Urinary 3 > Pharmacokinetics in Chronic Kidney Disease Patients > Flashcards

Flashcards in Pharmacokinetics in Chronic Kidney Disease Patients Deck (14)
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1
Q

Renal
Hepatic
Absorption
Distribution

A

Almost all slowed
Slowed of some
Increased of certain
Volume of distribution and plasma protein binding sometimes altered

2
Q

CKD renal drug elimination effects

A

Decreases elimination if undergoes GFR or tubular secretion

If mixed, then extra caution if kidnyes 30-40

3
Q

Most common used parameter to measure drug clearance

A

GFR

Renal elimination - scale linearly with GFR

If both - then scales linearly with changes in GFR and hepatic compoentn when GFR=0

4
Q

Hepatic effects

A

Largest decreases - CYP2C19, CYP3A4, N-acetyltransferares

Moderate - CYP2d6, glucuronyltransferases

Hepatic effects of accumulating uremic toxins may be involved

5
Q

Separate CKD effect

A

Hepatic metabolism converts a hydrophobic drug to hydrophilic metabolite…CKD allows it to accumulate and toxicity occurs

6
Q

CKD and oral bioailability

A

Most likely to occur when enzymatic activity decreases oral drug’s first pass effect…parenteral administration can bypass

7
Q

PLasma protein binding effects

A

Acidic drugs displaced from albumin by acids that accumulate

Highly bound weak acids with low therparutic index likely to be clinically significant (valproic acid)

More free drug so more pharm effect

Normal value for total drug but more free drug

8
Q

Chronic kidney dz and volume of distribution

A

Expansion of ECV - increased Vd…hydrophilic drugs that stay EC

Decreased binding to plasma proteins…increase…highly bound acidic drugs

Altered binding of drug to tissues…increase or decrease…digoxins tissue binding decreases in CKD

9
Q

Adjustment of maintenance doses in CKD

A

Adjust dosage amount, interval, or both

Trying to maintain same average plasma drug concentration

10
Q

Adjusting dosage amount

A

Dose decreased in proportion to renal function

Avwrage drug concentration stays same but max is lower than normal and min is higher than normal

11
Q

Adjusting interval

A

Interval scaled to proportion to renal function

Max, min and average are same as normal but drug concentration may be sub therapeutic or near toxic level for long periods

12
Q

Combination adjustment

A

Average same as normla

Max and min are closer than with dosage

Subtherapeutic or near toxic are shorter than with interval

13
Q

Adjustment of loading doseases

A

More drugs need loading doses in CKD

During IV infusion, drug undergoes exponential rise to SS concentraiton

CKD slows this so it takes longer

T1/2 becomes longer

14
Q

Loading dose calculation and when is it unaffected

A

Therapetuci plasma concentration=loading dose/Vd

Unaffected if therpatuic conenctration unchanceg and Vd unchanged