Pharmacology Chapter: Drug Excretion

What best defines the process of drug excretion?

Which of the following types of elimination involves removing drugs via urine?

What role do ABC transporters play in drug secretion?

Which means of drug excretion involves the liver and bile?

What happens to drugs that are reabsorbed after filtration in the kidneys?

Which percentage of blood flow is typically associated with renal drug excretion?

What process describes the initial filtration of plasma in the kidneys?

What is the primary route of drug excretion through the lungs?

What occurs with drugs that enter the bile from the liver?

During drug excretion, what process allows for the passive return of drugs from the renal tubules to the blood?

Drug Excretion

Drug excretion is the irreversible transfer of drugs or metabolites from the internal environment to the external environment.
This can occur through renal or non-renal routes.

Types of Elimination

Cellular: This type of elimination involves ABC transporters, such as P-glycoprotein/MDR1.
Renal: Approximately 25% of blood flows through the kidneys, making this route a significant pathway for drug excretion in urine.
Hepatic: Drugs can be transported from the liver into bile, entering the duodenum and subsequently excreted in feces.

Renal Drug Excretion Phases

Filtration: Plasma is filtered through the glomerulus, allowing most molecules, including drugs, to enter the filtrate.
Active Tubular Secretion: ABC transporters actively move selected drugs into the filtrate.
Reabsorption: Some drugs passively diffuse back into the bloodstream from the filtrate.
Elimination: Remaining drugs in the filtrate are collected in the bladder and excreted in urine.

Other Means of Drug Excretion

Biliary Excretion: Drugs can be eliminated through bile, passing from the liver to the intestine and eventually excreted in feces.
Milk Excretion: Some drugs can be transferred into breast milk, potentially exposing infants to their effects.
Pulmonary Excretion: Gas-soluble drugs can be eliminated through respiration, exhaled from the lungs with breath.

This quiz explores the various aspects of drug excretion, focusing on renal and non-renal elimination routes. It covers mechanisms involved in drug transport, including cellular, renal, and hepatic pathways. Test your understanding of filtration, active tubular secretion, and reabsorption processes in pharmacology.