Renal Disease And Dosing Considerations

Question 0

Factors affecting drug removal during dialysis

Answer 0

Molecular size, protein binding, volume of distribution, plasma clearance, and dialysis membrane

Drugs that are highly protein-bound such as warfarin are not usually removed during dialysis

Large drugs such as vancomycin are generally not removed unless a higher flux membrane with a large pore size is used

Question 1

Most common cause of CKD

Answer 1

Hypertension and diabetes

Question 2

A few examples of drugs not removed by hemodialysis

Answer 2

Amiodarone, ceftriaxone, insulin, vancomycin, and warfarin

Amiodarone is generally not removed due to its high volume of distribution

Question 3

Glomerulus

Answer 3

serves as a filter (if this filter is damaged protein can pass through) the level of albumin in the urine generally gauges the severity of kidney damage. Serum creatinine is also a determinate

Question 4

Proximal tubule

Answer 4

Large amounts of water sodium and chloride are absorbed here

Osmotic diuretics work in this area

Question 5

Loop of Henle

Answer 5

In the descending limb water is reabsorb but sodium chloride are not

In the ascending limb sodium and chloride are reabsorbed but water is not

Diuretics inhibit the sodium potassium pump in the ascending limb of the Loop of Henle

Question 6

Distal convoluted tubule

Answer 6

Regulates potassium, sodium, calcium, and pH

Dyazide diuretics work here by inhibiting the sodium chloride pump in the distal tubule

Thiazides also increase calcium absorption and have a long-term protective effect on bone

Question 7

Collecting duct

Answer 7

Aldosterone antagonist work here by blocking aldosterone, potassium increases

Question 8

Common drugs that require dose reductions or increased dosing intervals with decreased renal function

Answer 8

Acyclovir, allopurinol, amphotericin, aminoglycosides, Azole antifungal’s, antiarrhythmics, aztreonam, beta-lactam, colchicine, cyclosporine, dabigatran, famotidine, ranitidine, gabapentin, pregabalin, and Noxapater in, macrolides, metoclopramide, morphine and codeine, penicillin’s, quinolones, statins, Septra, vancomycin, venlafaxine

Question 9

Drugs that should not be used in severe renal impairment

Answer 9

Bisphosphonates, chlorpropamide, dabigatran, dofetilide, duloxetine, fondaparinux, foscarnet, glyburide lithium, my pyridine, metformin, nitrofurantoin, NSAIDs, potassium sparing diuretics, ribavirin, rivaroxaban, sotalol, tenofovir, tramadol, voriconazole

Question 10

Stages of CKD

Answer 10

Stage 1: >90 ml/min
Stage 2: 60 to 89
Stage 3: 30 to 59
Stage 4: 15 to 29
Stage 5: < 15 or dialysis dependent

Question 11

Gabapentin and metoclopramide

Answer 11

When used in severe renal impairment will have increased sedation drowsiness fatigue and with metoclopramide could have extrapyramidal symptoms

Question 12

Ace inhibitors and ARBs

Answer 12

Have been shown to prevent the progression of neuropathy in diabetic and nondiabetic patients with proteinuria

Goal blood pressure is less than 130/80

Note that when starting these agents you could notice a 30% rise in serum creatinine; do not need to stop unless greater than 30%

Question 13

What should you monitor and patients with kidney disease?

Answer 13

Serum creatinine, Albumin, phosphorus, calcium, vitamin D, and parathyroid hormone

Question 14

Phosphorus: phosphate binders

Answer 14

Agents used for hyperphosphatemia: aluminum-based agents, calcium-based agents, and aluminum free/calcium free agents

Aluminum-based agents: aluminum hydroxide (ALternaGEL, Amphogel)
Calcium-based agents: calcium acetate or PhosLo and calcium carbonate or tums
Aluminum free/calcium free agent: Sevelamer or renvela

Question 15

Common side effects associated with phosphate binders

Answer 15

Constipation, nausea, abdominal pain, diarrhea

Question 16

Contraindications for the use of renvela

Answer 16

Bowel obstruction

Question 17

Calcium binders

Answer 17

Cinacalcet (Sensipar)

Contraindication for use is hypocalcemia

Question 18

Treatment of vitamin D deficiency

Answer 18

30: normal

Question 19

Treatment of hyperkalemia

Answer 19

Normal potassium level is 3.5–5mEq/L

Drugs that raise potassium include potassium sparing diuretics, Ace inhibitors, ARBs, NSAIDs, oral contraceptives that contains drospirinone (yaz), cyclosporine, tacrolimus, heparin, invokana, potassium supplements, Septra

Treatment: next slide

Question 20

Treatment of hyperkalemia

Answer 20

1. Remove sources of potassium
2. Enhance potassium uptake via glucose administration and insulin administration
3. If metabolic acidosis give sodium bicarb: initiate if bicarb is <22 mEq/l
4. Consider beta agonist such as nebulized albuterol
5. Increase excretion with a loop diuretic such as furosemide
6. Kayexalate (SPS)
7. Dialysis
8. Calcium is almost always given to stabilize the cardiac tissue