Types of Drug Passage: Simple Diffusion vs Facilitated Diffusion

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What type of passive transfer mechanism is characterized by the movement of drugs along a concentration gradient without the need for a carrier or energy?

Facilitated diffusion

Filtration

Simple diffusion (correct)

Active transport

Which of the following factors does NOT affect the rate of drug passage across the cell membrane via simple diffusion?

Solubility in water

Presence of a carrier protein (correct)

Molecular weight and size

Concentration gradient

What type of passive transport mechanism involves the movement of drugs through water-filled pores in the cell membrane?

Simple diffusion

Filtration (correct)

Facilitated diffusion

Active transport

Which of the following statements about simple diffusion is NOT correct?

It requires a carrier protein Signup and view all the answers

Which of the following factors can increase the rate of drug passage across the cell membrane via simple diffusion?

Increasing the concentration gradient Signup and view all the answers

In which medium are basic drugs ionized?

Alkaline medium Signup and view all the answers

What state are acidic drugs in when present in an acid medium?

Non-ionized Signup and view all the answers

What happens to basic drugs in an acidic medium?

They remain non-ionized Signup and view all the answers

Which type of drugs are ionized in an acidic medium?

Acidic drugs Signup and view all the answers

What type of medium turns basic drugs into ionized form?

Alkaline medium Signup and view all the answers

Which form of weak acid and base drugs is more lipid-soluble and easily absorbed?

The non-ionized (unionized) form Signup and view all the answers

Which of the following factors primarily determines the absorption of weak acid and base drugs?

The pH of the absorption site Signup and view all the answers

For a weak base drug, which form is more likely to be absorbed in the acidic environment of the stomach?

The non-ionized form Signup and view all the answers

Which form of a weak acid drug is more likely to undergo renal excretion?

The ionized form Signup and view all the answers

Which statement is correct regarding the effect of pH on drug absorption and excretion?

Increasing pH favors ionization and excretion of weak acids Signup and view all the answers

In which type of media are weak base drugs more unionized?

Alkaline Signup and view all the answers

In which type of media are weak base drugs more ionized?

Acidic Signup and view all the answers

What happens to the ionization state of weak base drugs in acidic media?

Increase Signup and view all the answers

What is the predominant form of weak base drugs in alkaline media?

Unionized Signup and view all the answers

How does the ionization of weak base drugs change in basic media?

Decreases Signup and view all the answers

What is the significance of the oil/water partition coefficient for a drug?

A higher partition coefficient indicates better lipid solubility and absorption. Signup and view all the answers

What is the relationship between ionization and lipid solubility of a drug?

Decreased ionization leads to higher lipid solubility. Signup and view all the answers

What is the significance of the pKa value for a drug?

It represents the pH at which the drug is 50% ionized and 50% unionized. Signup and view all the answers

Which statement is true regarding the relationship between pH and ionization of a drug?

Drugs are more ionized at pH values below their pKa. Signup and view all the answers

Which factor is NOT directly related to the absorption of a drug?

Molecular weight of the drug Signup and view all the answers