Nephrology Flashcards
(207 cards)
1
Q
Definition: Passive transport from plasma into the renal tubule
A
Filtration
2
Q
Definition: when substances in tubule move to plasma
A
Reabsorption
3
Q
Definition: active transport of substances from plasma into renal tubule
A
Secretion
4
Q
Main process in glomerulus?
A
filtration
5
Q
Drugs that work on glomerulus?
A
NONE
6
Q
What is the first stop in the nephron?
A
glomerulus
7
Q
What controls filtrate formation in the glomerulus?
A
BP
8
Q
What is being formed in the glomerulus?
A
ultrafiltrate
9
Q
What is contained in the ultrafiltrate at the level of the glomerulus?
A
- Ions, small particles
- NOT proteins and RBCs
10
Q
Main process in PCT?
A
reabsorption; some secretion
11
Q
What is reabsorbed in the PCT/ percentages?
A
65% NaCl, K, Mg
85% nahco3
100% glu, AAs
12
Q
What is secreted in the PCT?
A
organic acids and bases
13
Q
Which meds work on the PCT?
A
CAIs
Adenosine antagonists
14
Q
First site of reabsorption?
A
PCT
15
Q
What is being reabsorbed and secreted in the LOH?
A
Reabsorption: 15-25% NaCl, K
-Ca, Mg
Secretion: Some K
16
Q
Which meds work on the LOH?
A
Loop diuretics
17
Q
What exact spot on the LOH do loops work?
A
thick ascending limb of LOH
18
Q
What is being reabs and secreted in the DCT?
A
Reabs: 4-8% Na, Cl
Sec: Ca (parathyroid control)
19
Q
What meds work on the DCT?
A
Thiazide diuretics
20
Q
What is being reabs and secreted in the cortical collecting tubule?
A
Reabs: 2-5% Na
Sec: K* and H+
21
Q
What meds work on the collecting tubule?
A
K sparing diuretics, adenosine antagonists
22
Q
What is being reabs and secreted in the medullary collecting duct?
A
Reabs: water
Sec: NOTHING
**collecting duct= final conc of urine
23
Q
What meds work on the collecting duct?
A
ADH antagonists
24
Q
List the drugs that are carbonic anhydrase inhibitors
A
Acetazolamide (oral), dorzolamide, brinzolamide (topical)
25
MC CAI?
Acetazolamide
26
the oral CAI is?
Acetazolamide
27
Topical CAI is?
dorzolamide, brinzolamide
28
The topical CAIs are used in which body part?
eyes (ophthalmic drops)
29
CAIs MOA?
Inhibits carbonic anhydrase, which is responsible for dehydrating H2CO3; reduces aqueous humor production
30
Bicarb buffer system
H2CO3-->
31
CAIs main effect on the body?
reduce aqueous humor production
32
CAIs and acid/base concs in body?
- H2CO3 (carbonic acid) which is a weak acid, is retained
- Urine contains less H+
- Blood contains more acid
33
CAIs ___ the pH of the urine
increase (more alkaline)
34
Indications of CAIs
*Glaucoma (main), urinary acidosis, metabolic alkalosis, acute mtn sickness, inc IOP post op cataract surgery, aspirin overdose
35
Absorption of CAIs?
absorbs well (oral and ocular)
36
Why are CAIs given in aspirin overdose?
aspirin is a weak acid and therefore will be excreted more quickly in alkaline urine
37
CAIs: onset, duration, peak
30 min, 12 hr, 2 hr
38
CAIs work on the... (part of nephron)
PCT
39
CAI ADRs
*drowsiness (MC), renal stones, K wasting, hypersensitivity rxn
40
CAI CIs
hepatic cirrhosis
41
Which dosage form of CAIs decreases systemic absorption, decreasing side effects?
ocular/topical (dorzolamide, brinzolamide)
42
What technique can be done to decrease systemic absorption of CAIs?
nasolacrimal duct block
43
How do you do the nasolacrimal duct block?
put drops in, close eyes, apply pressure to nasolacrimal ducts for 1-2 mins
-not guaranteed to completely prevent systemic absorption
44
Are CAIs usu used single or in combo?
BOTH! (combo w/ b-blockers)
45
What is H2CO3s conjugate base?
HCO3- (bicarbonate ion)
46
H2CO3 is a... (acid or base)
weak acid
47
Adenosine antagonists work on which parts of the nephron?
PCT, collecting tubule
48
Adenosine affects which parts of the nephron?
glomerulus, PCT, asc limb of LOH, collecting duct
49
Adenosine antagonists work how?
diuretic effects, work on coll tubule and PCT, work like caffeine
50
Name the Loop diuretics (4)
furosemide, torsemide, bumetanide, ethacrynic acid
51
MC loop used?
furosemide
52
MOA of loop diuretics?
```
Inhibits Na 2Cl K transporter;inhibits their active transport
Stop ions (Na, K, Cl) from being reabsorbed, more are excreted into the urine along with H2O
```
53
Loops work on what part of nephron?
thick ascending limb of LOH
54
Indications of Loops?
- *Edema (MC, very effective)- CHF
- HTN (less used for this)
- Hypercalcemia, hyperkalemia (gets rid of excess ions in the plasma)
- Anion overdose (fluoride, bromide, iodide)
55
T or F, Loops are a high ceiling effect med?
True. (ceiling effect- near max diuretic effect; if you go over max, won't be beneficial)
56
Loops in combo with what have bet combined effect/highest amount of Na blocking over time?
thiazides
57
Loops absorption
orally well absorbed
58
Loops available in these routes of administration:
oral, IV
59
What are the best drugs to diurese pts?
loops
60
Torsemide vs furosemide onset and duration?
T: o- 1 hr, d- 4-6 hrs (short onset, long duration)
F: o- 2-3 hrs, d: 2-3 hrs (longer onset, shorter duration)
61
Loops ADRs
- hypo- mg, ca, k, na, cl
- hyperuricemia
- ototoxicity (if given w/ other ototoxic meds)
- allergic rxn
- increase Scr
62
Loops CIs
- overuse in hepatic cirrhosis, renal failure (nephrotoxic, heart failure
- sulfa allergies
63
best loop to give in sulfa allergic pt?
ethacrynic acid (no sulfa group)
64
Loop diuretic drug-drug interactions
NSAIDs- will decrease effectiveness of loops. Don't stop NSAIDs, just find a balance
65
Furosemide PO:IV conversion
2:1 (ex 40 mg PO= 20 mg IV)
66
Torsemide PO:IV conversion
1:1
67
Bumetanide PO:IV conversion
1:1
68
Conversion btw loops (F:T:B)
40 mg furosemide= 20 mg torsemide= 1 mg bumetanide
69
most potent loop?
bumetanide
70
Are diff loops interchangeable?
yes, can switch from one to another at any time
71
List the thiazide diuretics
HCTZ, chlorothiazide
72
List the thiazide-like diuretics
metolazone, indapamide, chlorthalidone
73
Which drug class has a ceiling effect?
loop diuretics
74
MOA of thiazides?
Inhibit NaCl transporter, enhance Ca reabsorption; NaCl and water are excreted
75
Which part of nephron do thiazides work?
DCT
76
Thiazides indications
*HTN (MC), heart failure, nephrogenic DI, nephrolithiasis
77
Thiazides absorption
Slowly
78
Which thizide or thiazide like diuretic absorbs the slowest but has the longest duration of action?
chlorthalidone (thiazide-like)
79
MC used thiazide in practice?
HCTZ
80
Thiazides are weak or strong diuretics?
weak
81
Thiazides ADRs
- hypo- Na, Cl, K,
- hyper- uric acid, Ca, glucose, lipids
- allergic rxn (sulfa)
- photosensitivity
- orthostatic hypotension (minimal)
82
Thiazides CIs
-Overuse in: hep cirrhosis, renal failure, CHF (dont give high doses)
83
Thiazides caution in pts with which allergy?
sulfa
84
Thiazides may be ineffective in these pts
pts w/ CrCl less than 20 ml/min, EXCEPT metolazone (thiazide like)
85
Only thiazide that is effective in pts w/ low CrCl?
metolazone (thiazide-like)
86
Which thiazide diuretic is the only one that is available in IV form?
chlorothiazide (thiazide)
87
What routes of admin are thiazides available in?
oral (most) and IV (chlorthiazide)
88
What drug class are not structurally like thiazides, but contain a sulfonamide group and have the same MOA as thiazides?
thiazide-like diuretics
89
List the K- sparing (aldosterone receptor blocker) diuretics
Spironolactone, eplerenone
90
List the other K- sparing agents
Triamterene, amiloride
91
K- sparing (aldosterone receptor blocker) diuretics MOA
block aldosterone receptors (antagonize mineralcorticoid receptors) in the collecting tubules, preventing aldosterone from binding; More K and H stays in plasma
92
Where in the nephron do K- sparing (aldosterone receptor blocker) diuretics work?
cortical collecting tubule
93
Indications for K- sparing (aldosterone receptor blocker) diuretics
- hypokalemia prevention and tx
| - Spironolactone: hyperaldosteronism, PCOS, hirsutism
94
T or F? Spironolactone has a slow onset, duration, and peak?
True
95
Does spironolactone take a while to reach therapeutic levels?
Yes- several days
96
K sparing diuretics ADRs (all types)
hyperkalemia
97
Spironolactone ADRs
gynecomastia, impotence, tumorogenic (animals)
98
K sparing diuretics CIs (all types)
hyperkalemia, renal impairment, hepatic impairment
99
Spironolactone CIs
Addison's dz
100
Eplerenone drug-drug interactions
-strong CYP3A4 agents- grapefruit, fluconazole, diltiazem (EPLERENONE ONLY)
101
K sparing diuretics (other) MOA
inhibits JUST the Na ion channels in the collecting tubules
102
Triamterene onset and duration
o- 2-3 hrs
| d- 7-9 hrs
103
Triamterene ADRs
kidney stones
104
Which is more effective, triamterene or spironolactone?
spiro
105
List the INDIRECT ADH antagonists
Lithium, demeclocycline
106
List the DIRECT ADH antagonists
conivaptan, tolvaptan
107
T or F? Li and Na are the same size
T
108
INDIRECT ADH antagonists MOA?
unknown; DO NOT work on ADH receptors
109
DIRECT ADH antagonists MOA?
inhibit vasopressin (ADH) receptors; ADH blocked and H2) is not retained
110
ADH antagonists work on which part of the nephron?
collecting duct
111
Are ADH antagonists used often?
No
112
ADH antagonists (direct and indirect) indications
CHF, SIADH
113
Direct ADH antagonists onset/peak/duration?
o- 2-4 hrs
p- 4-8 hrs
d- 24 hrs
114
How often are direct ADH antagonists taken per day?
1x/day (bc they last 24 hrs)
115
Direct ADH antagonists ADRs?
Nausea, dry mouth, thirst
116
Direct ADH antagonists CIs?
hypovolemia, hyponatremia
117
Direct ADH antagonists drug-drug interactions?
-strong CYP3A4 agents- grapefruit juice, fluconazole, diltiazem
118
List the osmotic diuretics
Glycerol, mannitol
119
Mannitol available forms?
PO, inhalation, IV
120
Osmotic diuretics MOA?
increase osmotic pressure in the glomerulus, decreasing water and electrolyte reabsorption
121
Osmotic diuretics indications?
- cerebral edema (head injury)
- acute glaucoma
- bronchial hyperresponsiveness
122
Describe the absorption, excretion, duration of osmotic diuretics?
poorly absorbed, quickly excreted, don't last long
123
Osmotic diuretics ADRs?
- Glycerol (oral form)- N/V/Diarrhea
- Mannitol- excess volume expansion, can cause HF, edema, pulm congestion (pulling water out of bloodstream into the tissues)
124
Osmotic diuretics CIs
hypersensitivity
125
How should you take oral osmotic diuretics?
mix w/ small amount of juice (OJ preferred), add ice, sip SLOWLY, small sips
126
How should IV mannitol be infused?
SLOWLY
127
Mannitol IV is indicated for what pt population?
inpts, esp head injury, edema
128
Sulfonamide chemical structure?
SO2NH2
129
How many chemical arrangements of sulfonamides are there?
3
130
Can pts w/ sulfa abx allergy receive loop diuretics?
yes. caution. best=ethacrynic acid
131
No cross sensitivity for sulfonamide allergic pts taking loops:
abx, other sulfonamide containing meds
132
3 questions to ask pt when they say they have a med allergy?
- what allergies?
- what happens?
- how long ago?
133
Definition: Volume of plasma filtered across the glomerulus per unit of time
glomerular filtration rate (GFR)
134
MC method for measuring kidney fn?
GFR
135
The GFR reflects the number of..
functioning nephrons in the kidney
136
GFR normal range
90-120 ml/min
137
T or F? GFR is easy to measure directly
F
138
Definition: endogenous byproduct of musc metabolism
serum creatinine
139
how much of Cr is cleared by the kidneys? (%)
100%
140
__% of Cr is cleared by glomerular filtration, and __% through tubular secretion
90%, 10%
141
Scr is ____ (lower/higher) in elderly and paraplegics?
lower (less musc tone/mass)
142
How do you DIRECTLY measure renal fn/creat?
24 hr urine collection
143
How do you INDIRECTLY measure renal fn/creat?
calculation based on SCr
144
Definition: rate at which the kidneys clear Cr from the blood
CrCl
145
Name of the formula used to calculate CrCl
cockroft-gault formula
146
when calculating crcl on females, what do you have to add to your calc?
multiply by 0.85
147
If pts body weight is less than IBW, use the ___
actual body weight
148
If pts body weight is 20% more than IBW, use the ____
adjusted body weight
149
If pts weight is more than IBW, but less than 20% above it, use the ____
ideal body weight
150
AKI clinical presentation
-inc Scr, dec GFR, accumulation of nitrogenous wastes, inability to regulate fluids/electrolytes/acid base balance, weight gain (edema), foamy urine, changes in urinary habits
151
3 categories of AKI
Prerenal, intrinsic, postrenal (also functional?)
152
AKI from hemodynamic changes without hypotension or structural damage
functional
153
Decrease in renal perfusion
prerenal azotemia
154
Structural damage inside the kidney
intrinsic
155
obstruction of urine flow
postrenal
156
Prerenal: urine sediment
normal
157
Prerenal: urine RBCs
none
158
Prerenal: urine WBCs
none
159
Prerenal: urine Na
Less than 20
160
Prerenal: urine/serum osmolarity
>1.5 (highest of the 3)
161
Prerenal: urine/scr
>40:1 (highest)
162
Prerenal: BUN/Scr
>20 (highest)
163
Intrinsic: urine sediment
casts, cellular debris
164
Intrinsic: urine RBCs
2-4+ (most)
165
Intrinsic: urine WBCs
2-4+ (most)
166
Intrinsic: urine Na
>40
167
Intrinsic: urine/serum osmo
Less than 1.3
168
Intrinsic: urine/Scr
Less than 20:1
169
Intrinsic: BUN/Scr
15
170
Postrenal: urine sediment
cellular debris
171
Postrenal: urine RBCs
variable
172
Postrenal: urine WBCs
1+ (middle)
173
Postrenal: urine Na
>40
174
Postrenal: urine/serum osmo
Less than 1.5
175
Postrenal: urine/Scr
Less than 20:1
176
Postrenal: BUN/Scr
15
177
Name the type of AKI caused by: hypovolemia
prerenal
178
Name the type of AKI caused by: obstruction (upper-kidney, lower-bladder, prostate, catheter)
postrenal
179
Name the type of AKI caused by: decreased cardiac output
prerenal
180
Name the type of AKI caused by: radiocontrast dyes, APAP, cisplatin
intrinsic (acute tubular necrosis)
181
Name the type of AKI caused by: rhabdomyolysis
intrinsic (acute tubular necrosis)
182
Name the type of AKI caused by: decreased blood volume
prerenal
183
Name the type of AKI caused by: infection
intrinsic
184
Name the type of AKI caused by: ACE-I, NSAIDS
prerenal (impair renal perfusion)
185
Name the type of AKI caused by: PCN, cephalosporins, sulfonamides, rifampin, phenytoin, furosemide, PPIs, NSAIDs
intrinsic (nephritis)
186
How many stages of AKI/ARF are there?
3
187
How are the stages classified (what are they based on?)
Scr and urine output
188
Normal Scr value (men)
0.7-1.3 mg/dL
189
Normal Scr value (women)
0.6-1.1 mg/dL
190
What is used as the reference Scr?
lowest Scr recorded in the last 3 months
191
What are the 3 urine output classifications?
non-oliguria (normal), oliguria, anuria
192
non-oliguria numbers
adults >400 ml/day or >.5 ml/kg/hr
| peds >1ml/kg/hr
193
peds UO classified based on___
weight
194
oliguria #s (adults)
A-less than 400 ml/ day or less than 0.5 ml/kg/hr for >6hrs
195
Anuria #s (BOTH adults and peds)
Less than 50 mls/day
196
Medication induced AKI: Which meds change renal hemodynamics by vasoconstricting the afferent arteriole?
NSAIDs, cyclosporine, tacrolimus, amphotericin B, radiocontrast agents, vasopressores
197
Medication induced AKI: Which meds change renal hemodynamics by vasodilating the efferent arteriole?
ACEIs, ARBs, diltiazem, verapamil
198
Medication induced AKI: Which meds cause direct toxicity to the renal tubules?
aminoglycosides, amphotericin B, radiocontrast agents, cisplatin/carboplatin (platinum chemotherapy agents)
199
5 things that place pt at higher risk for AKI
- hx CKD
- increased age
- comorbid conditions (DM)
- dehydration
- pt on AKI inducing medication
200
Most important way to prevent AKI, esp when giving direct tubular toxic agents
adequate hydration, dilute toxic agents
201
What steps do you need to take before giving a pt a radiocontrast agent?
- administer oral or IV hydration for 6-12 hrs prior
- Give NAC (N-acetylcysteine)- 4 doses PO
- Use low or iso-osmolar agent
202
Steps for tx of AKI (4)
- Evaluate pt fluid status (hyper or hypovolemic)
- ID cause of AKI (meds?)
- Review meds for renal dose adjustments
- Supportive therapy
203
If AKI pt is hypervolemic, how would you tx?
diuretic or renal replacement therapy (dialysis)
204
If AKI pt is hypovolemic, how would you tx?
fluids (crystalloid, colloid)
205
If cause of AKI is medication elated, what do you do?
- stop offending med
| - start steroids (prednisone or methylprednisolone)
206
What is included in supportive therapy for AKI pts?
- dialysis
| - adequate hydration
207
T or F, there is a drug that has been proven to accelerate the recovery of renal failure
F- NONE; protection/prevention is key
