Metabolism and Excretion

Which statement is true regarding first-pass metabolism?

• Metabolism that occurs before absorption

• Metabolism that occurs before distribution

• Metabolism that occurs after distribution

• Metabolism that occurs after excretion

• Metabolism that occurs before elimination

A prodrug is a drug formulation that is inactive, thus it can directly provide an effect after administration

• true

• false

Phase 1 metabolism is largely performed by CYP 450 enzymes.

• true

• false

If an active drug (A) is consumed together with another drug (B) that acts as an enzyme inducer of CYP 450, what will happen?

• drug A will accumulate in the blood

• drug A will have toxic effects

• many metabolites of drug B will be formed

• the effect of drug B will increase

• the amount of drug A at the site of action decreases

Paracetamol undergoes phase 1 metabolism and is converted to NAPQI, which is normally further metabolized in phase 2 by conjugation with GSH, resulting in a toxic metabolite.

• true

• false

Drugs will be filtered through the glomerulus using:

• passive diffusion

• facilitated diffusion

• active transport

• endocytosis

• pinocytosis

Weak acid drugs will be eliminated from the body when

• the urine pH is acidic, so many drugs are reabsorbed

• the urine pH is acidic, so many drugs are not ionized

• the urine pH is basic, so many drugs are ionized

• the urine pH is basic, so many drugs are non-polar

• the urine pH is acidic, so many drugs are trapped in the urine

Drugs that are polar will mostly reach the kidneys through

• glomerular filtration

• active secretion in the proximal tubule

• reabsorption in the distal tubule

The range of therapy is

• duration of drug effect

• the time required to produce an effect since the drug is given

• the amount and time the drug is in systemic circulation

• minimum effective concentration

• the distance between KEM and KTM

The drug that is excreted through feces is a drug that cannot be absorbed and a drug that binds with bile.

• true

• false