Drug Movement in ADME Mechanisms Quiz

Mechanisms of Drug Movement

• Active transport requires a carrier and energy.
• Passive transport does not require a carrier or energy.
• Facilitated diffusion is necessary for the transport of endogenous compounds with slow movement by simple diffusion.
• Passive transport is the main mechanism for the transport of the majority of drugs in the body.

Transport Mechanisms

• Endocytosis involves the transport of drugs by being engulfed within molecular vesicles.
• Simple diffusion involves the movement of a drug molecule according to its concentration gradient.

Drug Ionization

• A basic drug is less ionized in an acidic medium.
• The pKa is the pH at which a drug is 50% ionized and 50% non-ionized.

Barriers to Drug Movement

• Lipid-soluble drugs can cross the blood-brain barrier by simple diffusion.
• The blood-brain barrier mainly protects against the passage of hydrophilic substances.
• The extent of drug absorption through the placental barrier is determined by the drug's lipophilicity.
• The passage of a drug across a cell membrane is determined by its lipophilicity and the concentration gradient.
• The main function of the blood-brain barrier is to protect the central nervous system from toxic substances.
• An acidic drug is less ionized in an alkaline medium.

Test your knowledge on the mechanisms of drug movement during ADME (Absorption, Distribution, Metabolism, and Excretion). Learn about passive diffusion, active transport, facilitated diffusion, and pinocytosis as mechanisms for drug transport in the body.