Vercaigne's Stuff (Renal Dosing & Hemodialysis)

Question 1

Formula for creatinine clearance?

Answer 1

CrCl = [(140-age)(80)(0.85 if female)]/Scr

Question 2

CrCl: 60-89

Answer 2

mildly decreased renal fcn

Question 3

CrCl: 45-59

Answer 3

mildly to moderately decreased renal fcn

Question 4

CrCl: 30-44

Answer 4

moderately to severely decreased fcn

Question 5

CrCl: 15-29

Answer 5

severely decreased renal fcn

Question 6

CrCl: < 15

Answer 6

kidney failure

Question 7

What CrCl do you have to have to be on hemodialysis?

Answer 7

< 10

Question 8

CrCl: >90

Answer 8

normal or high kidney fcn

Question 9

In what situations is the CrCl equation not valid?

Answer 9

• ppl under 18
• renal function is not stable
• extremely obese, paralyzed patients, amputees, pregnancy
• ppl who have vegetarian diets, taking creatine supplements, or ppl taking medications that inhibit the tubular secretion of creatinine (trimethoprim, fenofibrate)

Question 10

Is linagliptin removed by the kidneys?

Answer 10

Only 5% unchanged excreted in urine.

80% excreted in feces.

Question 11

Would you need to change the dose of linagliptin in someone with decreased renal fcn?

Answer 11

No

Question 12

Is metformin excreted by the kidneys?

Answer 12

Yes-90% excreted as unchanged drug

Question 13

Would you need to change the dose of metformin in someone with decreased renal fcn?

Answer 13

YES - never give to anyone with CrCL < 30 mL/min

**it will accumulate and cause lactic acidosis and WILL KILL YOU

Question 14

Is Candesartan excreted by the kidneys?

Answer 14

33% excreted in urine (26% as unchanged drug)

67% in feces

Question 15

Would you need to change the dose of candesartan in someone with decreased renal fcn?

Answer 15

Maybe.
You would check BP, K+ levels and make sure SCr is stable.
If all is good, do not need to change.

*For moderate-severe renal impairment: Consider initial dose of 4 mg once daily in pts with hypertension

Question 16

Is ASA excreted by the kidneys?

Answer 16

Excreted in the urine 85% as active metabolites

Question 17

Would you need to change the dose of ASA in someone with decreased renal fcn?

Answer 17

No

• But it is important to know that 81 mg of ASA will not affect prostaglandin effect
• The benefit of using low-dose aspirin outweighs any risk associated with nephropathy or other adverse effects even in the setting of severe renal impairment.

Question 18

Is Varenicline excreted by the kidneys?

Answer 18

92% excreted unchanged in the urine

Question 19

Would you need to change the dose of Varenicline in someone with decreased renal fcn?

Answer 19

YES.

Initiate 0.5 mg once daily and then get up to 0.5 mg BID.

Question 20

Is Gabapentin excreted by the kidneys?

Answer 20

YES - 100% RENALLY ELIMINATED

*accumulation will soon cause CNS toxicity

Question 21

Would you need to change the dose of gabapentin in someone with decreased renal fcn?

Answer 21

ABSOLUTELY.

For janice, she had a CrCl 15-29 so we would recommend 200-700 mg once daily.

From Lexi:
CrCl ≥60 mL/minute: 300 to 1,200 mg 3 times daily

CrCl >30 to 59 mL/minute: 200 to 700 mg twice daily

CrCl >15 to 29 mL/minute: 200 to 700 mg once daily

CrCl 15 mL/minute: 100 to 300 mg once daily

CrCl <15 mL/minute: Reduce daily dose in proportion to creatinine clearance based on dose for creatinine clearance of 15 mL/minute (eg, reduce dose by one-half [range: 50 to 150 mg/day] for CrCl 7.5 mL/minute)

Question 22

Is naproxen excreted by kidneys?

Answer 22

yes - 95% excreted as metabolites

Question 23

Would you need to change the dose of naproxen in someone with decreased renal fcn?

Answer 23

Yes.
CrCl > 30 = use naproxen with caution; consider dose reduction

CrCl < 30 = naproxen is contraindicated

Question 24

Is colchicine excreted by the kidneys?

Answer 24

excreted in the urine (40-65% as unchanged drug)

Question 25

Would you need to change the dose of colchicine 0.6mg daily in someone with decreased renal fcn?

Answer 25

Maybe.

CrCl < 30 = dose decrease not required but may be considered. Treatment course should not be repeated more frequently than every 14 days.

OR

0.3 mg daily, use with caution if dose is titrated

Question 26

Is allopurinol excreted by the kidneys?

Answer 26

Yes.

Excreted in urine 76% as oxypurinol (active metabolite)

Question 27

What is a typical uric acid level?

Answer 27

357 micro mol/L

*Remember 357 chevy ????

Question 28

Should allopurinol be decreased in ppl with renal impairment?

Answer 28

Yes

From Lexi:
CrCl 10 to 20 mL/minute: 200 mg/day

CrCl 3 to 10 mL/minute: Do not exceed 100 mg/day.

CrCl <3 mL/minute: The dosing interval may need to be extended; do not exceed 100 mg/day.

Initiate therapy with 50 to 100 mg daily, and gradually increase to a maintenance dose to achieve a serum uric acid level of ≤6 mg/dL

initiate therapy at 50 mg/day, increasing the dose every 2 to 5 weeks to achieve desired uric acid levels of <6 mg/dL

Question 29

Properties affecting if a drug will be removed during hemodialysis:

Molecular weight

Answer 29

Small MW molecules (< 5000 Da) will be removed

Large MW molecules (>5000 Da) will not be easily removed

Question 30

Properties affecting if a drug will be removed during hemodialysis:

Protein binding

Answer 30

Highly protein bound (>90-95%) are typically not easily removed

Question 31

Properties affecting if a drug will be removed during hemodialysis:

Volume of distribution

Answer 31

Drugs with large Vd (>1L/kg) are typically widespread and will not be as easily removed by dialysis

Drugs with small Vd (<1L/kg) are not as widely distributed and will be removed

Question 32

Is Venlafaxine excreted by kidneys?

Answer 32

Yes.

87% removed from urine as active metabolic ODV

Question 33

What 3 drugs have active metabolites that we went over in class?

Answer 33

• allopurinol
• venlafaxine
• famciclovir

Question 34

Should a pt on hemodialysis receive a dose decrease of venlafaxine?

Answer 34

Yes

Reduce total daily dose by 50% or more

Question 35

Is famciclovir excreted by the kidneys?

Answer 35

Yes

Excreted in Urine (73% primarily as penciclovir)
*active metabolite

Question 36

Should a pt on hemodialysis receive a dose decrease of famciclovir?

Answer 36

Yes

Administer 250 mg after each dialysis session.