E. Excretion

Proverbs 16:3

excretion

• metabolism = initial pathway for elimination

Final pathway for elimination.

a. Metabolism

b. Excretion

c. Distribution

d. Absorption

d. Kidney

Other sites:

• body fluids (breast milk, feces, saliva, sweat)

• enterohepatic circulation

The primary site of drug excretion

a. Breast milk
b. Feces
c. Sweat
d. Kidney

• Body fluids (breast milk, feces, saliva, sweat)

• Enterohepatic circulation

Other sites of drug excretion [2]

• Hydrophilic

• Ionized

• Polar

• Excreted

📌Mnemonic: “HIPE”

The goal of drug excretion

a. Hydrolysis, Ionization, Precipitation, Excretion
b. Hepatic, Intestinal, Pulmonary, Elimination
c. Hydrophilic, Ionized, Polar, Excreted
d. Hepatic, Intestinal, Peripheral, Elimination

b. Zero order kinetics

The kinetics where the:

• amount and rate are fixed

• concentration independent

a. First order kinetics
b. Zero order kinetics

b. Zero order kinetics

Amount excreted is fixed

a. First order kinetics
b. Zero order kinetics

b. Zero order kinetics

Rate is fixed

a. First order kinetics
b. Zero order kinetics

a. First order kinetics

% excreted is fixed

a. First order kinetics
b. Zero order kinetics

a. First order kinetics

The concentration dependent kinetics
a. First order kinetics
b. Zero order kinetics

a. First order kinetics

Increase concentration = increase elimination
a. First order kinetics
b. Zero order kinetics

• Aspirin

• Morphine

• Phenytoin

• Warfarin

• Heparin

• Ethanol

• Theophylline

• Tolbutamide

📌Mnemonic: “AMPWHETT”

Drugs following Zero Order kinetics [6]

(IPS to)

First order kinetics vs Zero order kinetics:

(IPS to)

First order kinetics vs Zero order kinetics:

c. T½ = ln2 × Vd / Cl

• time it takes to reduce the initial concentration by half

The half-life formula

a. T½ = ln2 × Cl / Vd
b. T½ = ln2 / (Cl × Vd)
c. T½ = ln2 × Vd / Cl
d. T½ = Vd / (ln2 × Cl)

• Intracellular

• Extravascular

• Longer T½

• Longer stay in body

The characteristics of Low Volume of Distribution (Vd)

a. Extracellular, intravascular, shorter T½, shorter stay in body
b. Intracellular, extravascular, longer T½, longer stay in body
c. Intravascular, shorter T½, shorter stay in body
d. Extracellular, shorter T½, not available for elimination

b. Shorter T½ and shorter stay in body

The characteristics of High Clearance

a. Longer T½ and longer stay in body
b. Shorter T½ and shorter stay in body
c. Longer T½ and shorter stay in body
d. Shorter T½ and longer stay in body

• Extracellular

• Intravascular

• Shorter T½

• Shorter stay in body

The characteristics of Low Volume of Distribution (Vd)

a. Extracellular, intravascular, shorter T½, shorter stay in body
b. Intracellular, extravascular, longer T½, longer stay in body
c. Intravascular, shorter T½, shorter stay in body
d. Extracellular, shorter T½, not available for elimination

a. Longer T½ and longer stay in body

The characteristics of Low Clearance

a. Longer T½ and longer stay in body
b. Shorter T½ and shorter stay in body
c. Longer T½ and shorter stay in body
d. Shorter T½ and longer stay in body

d. Nephron

The functional unit of the kidney

a. Glomerulus
b. Collecting duct
c. Loop of Henle
d. Nephron

d. Glomerular Filtration Rate

The primary measure of renal function that cannot be measured directly

a. Creatinine clearance
b. Cystatin C
c. Serum creatinine
d. Glomerular Filtration Rate

d. Creatinine

The normal waste product of muscle metabolism used to approximate GFR

a. Urea
b. Uric acid
c. Cystatin C
d. Creatinine

d. Cockcroft-Gault equation

The equation used to calculate Creatinine Clearance

a. CKD-EPI formula
b. Henderson-Hasselbalch equation
c. Arrhenius equation
d. Cockcroft-Gault equation

$$CrCl = \frac{(140 - \text{age}) \times (\text{weight in kg}) \times 0.85}{72 \times \text{serum creatinine}}$$

🧠NOTE: Male has higher muscle mass

The Cockcroft-Gault equation for female patients

$$CrCl\ (mL/min)=\frac{(140-\text{age in years})\times(\text{weight in kg})}{72\times\text{serum creatinine in mg/dL}}$$

The Cockcroft-Gault equation for male patients:

• Age

• Serum creatinine

• African-American ethnicity

The variables used in the CKD-EPI formula [3]

a. Age, serum creatinine, and African-American ethnicity
b. Age, weight, and genetic Polymorphism
c. Age, sex, and serum albumin
d. Age, weight, and body surface area

• ↑ creatinine = ↓ CrCl = ↓ eGFR ❌

• ↓ creatinine = ↑ CrCl = ↑ eGFR ✅

Relationship of creatinine, CrCl and eGFR:

d. Cystatin C

The alternative marker used to assess GFR in elderly patients with decreased muscle mass where creatinine clearance is not accurate

a. Serum albumin
b. Uric acid
c. Blood urea nitrogen
d. Cystatin C

Explain mo nalang Please 🧠

Nephrotoxic MOT of ARBS, ACEIs, and NSAIDs

a. Probenecid inhibits tubular secretion of penicillin → increase levels of penicillin

How does the combination of probenecid + penicillin increase levels of penicillin?

a. Probenecid inhibits tubular secretion of penicillin → increase levels of penicillin

b. Probenecid inhibits hepatic glucuronidation of penicillin → increase levels of penicillin

c. Probenecid displaces penicillin from plasma albumin → increase free levels of penicillin

d. Probenecid decreases the volume of distribution of penicillin → increase plasma levels of penicillin

d. Proximal convoluted tubule

The primary site of tubular reabsorption

a. Distal convoluted tubule
b. Loop of Henle
c. Collecting duct
d. Proximal convoluted tubule

Explain mo nalang Please 🧠

Apply the LUNA and HIPE

Effects of pH in drug elimination:

d. Urinary alkalinizer

• Sodium bicarbonate

The treatment for ASA (aspirin) overdose to enhance excretion

a. Urinary acidifier
b. Dialysis
c. Activated charcoal
d. Urinary alkalinizer

a. Urinary acidifier

• Vitamin C

• Ammonium chloride

The treatment for Amphetamine overdose to enhance excretion

a. Urinary acidifier
b. Dialysis
c. Activated charcoal
d. Urinary alkalinizer

b. Creatinine increase by ≥ 0.3 within 48 hours

The diagnostic criterion for Acute Kidney Injury

a. eGFR < 60 for ≥ 3 months
b. Creatinine increase by ≥ 0.3 within 48 hours
c. eGFR < 15 (end stage renal disease)
d. Creatinine increase by ≥ 0.5 within 24 hours

a. eGFR < 60 for ≥ 3 months

The diagnostic criterion for CKD

a. eGFR < 60 for ≥ 3 months
b. Creatinine increase by ≥ 0.3 within 48 hours
c. eGFR < 15 (end stage renal disease)
d. Creatinine increase by ≥ 0.5 within 24 hours

• Dehydration

• Infection

• Drug-induced

Causes of Acute Kidney Injury include ______ [3]

a. T2 DM, HTN, and Glomerulonephritis
b. Dehydration, infection, and drug-induced
c. Lupus and chronic hypertension
d. Glomerulonephritis and T2 DM only

• Type 2 DM

• Hypertension (HTN)

• Glomerulonephritis

Causes of Acute Kidney Injury include _____

a. Type 2 DM, Hypertension (HTN), and Glomerulonephritis
b. Dehydration, infection, and drug-induced
c. Lupus and chronic hypertension
d. Glomerulonephritis and T2 DM only

c. Address the underlying cause

• dehydration → hydration

• infection → antibiotic

• drug induced → discontinue drug use

Management of Acute Kidney Injury include _____

a. Dialysis and kidney transplant
b. Renal replacement therapy only
c. Address the underlying cause
d. Kidney transplant

• Dialysis / Renal replacement therapy

• Kidney transplant

Management of Chronic Kidney Disease (CKD) include _______

a. Hydrate, antibiotics, and discontinue drug use
b. Address the underlying cause only
c. Dialysis/renal replacement therapy and kidney transplant
d. Antibiotics and hydration o

d. > 90

eGFR range for CKD Stage 1

a. 60–89
b. <15
c. 30–44
d. > 90

a. 60–89

eGFR range for CKD Stage 2

a. 60–89
b. <15
c. 30–44
d. > 90

d. 45–59

eGFR range for CKD Stage 3a

a. 30–44
b. 60–89
c. 15–29
d. 45–59

a. 30–44

eGFR range for CKD Stage 3b

a. 30–44
b. 60–89
c. 15–29
d. 45–59

d. 15–29

eGFR range for CKD Stage 4

a. 30–44
b. < 15
c. 45–59
d. 15–29

d. < 15

eGFR value indicating CKD Stage 5 (End Stage Renal Disease)

a. > 90
b. < 10
c. > 100
d. < 15