Podcast
Questions and Answers
Which type of drug is likely poorly absorbed when given orally?
Which type of drug is likely poorly absorbed when given orally?
What role does increased vascularity of the absorbing surface play in drug absorption?
What role does increased vascularity of the absorbing surface play in drug absorption?
Which formulation can be used to overcome the acid lability of certain drugs?
Which formulation can be used to overcome the acid lability of certain drugs?
What effect do P-glycoprotein (P-gp) inducers have on the bioavailability of certain drugs?
What effect do P-glycoprotein (P-gp) inducers have on the bioavailability of certain drugs?
Signup and view all the answers
How does the pH of the gastric environment affect drug absorption?
How does the pH of the gastric environment affect drug absorption?
Signup and view all the answers
Which of the following drugs is likely to have low oral bioavailability due to the efflux transporter P-gp?
Which of the following drugs is likely to have low oral bioavailability due to the efflux transporter P-gp?
Signup and view all the answers
What primarily determines the rate of passive diffusion of a drug across a membrane?
What primarily determines the rate of passive diffusion of a drug across a membrane?
Signup and view all the answers
What type of drugs are typically absorbed faster in the gastrointestinal tract?
What type of drugs are typically absorbed faster in the gastrointestinal tract?
Signup and view all the answers
What is pKa in relation to weak electrolytes?
What is pKa in relation to weak electrolytes?
Signup and view all the answers
What is the main mechanism through which insulin and neurotransmitters are released from cells?
What is the main mechanism through which insulin and neurotransmitters are released from cells?
Signup and view all the answers
Concurrent administration of which of the following could affect drug absorption in the gastrointestinal tract?
Concurrent administration of which of the following could affect drug absorption in the gastrointestinal tract?
Signup and view all the answers
Which statement is true regarding weak acids and their behavior in relation to pH?
Which statement is true regarding weak acids and their behavior in relation to pH?
Signup and view all the answers
Which factor significantly affects the rate of drug absorption after administration?
Which factor significantly affects the rate of drug absorption after administration?
Signup and view all the answers
Which scenario describes a situation where drug absorption is likely delayed?
Which scenario describes a situation where drug absorption is likely delayed?
Signup and view all the answers
What is the role of the membrane during passive diffusion of drugs?
What is the role of the membrane during passive diffusion of drugs?
Signup and view all the answers
What can influence the rate of diffusion through paracellular channels?
What can influence the rate of diffusion through paracellular channels?
Signup and view all the answers
What role does gastric acid play in the absorption of ketoconazole?
What role does gastric acid play in the absorption of ketoconazole?
Signup and view all the answers
In which scenario is absorption of most drugs generally improved?
In which scenario is absorption of most drugs generally improved?
Signup and view all the answers
What is the relationship between ionized and unionized forms of a weak acid at pH = pKa?
What is the relationship between ionized and unionized forms of a weak acid at pH = pKa?
Signup and view all the answers
What type of transport mechanism is least energy-dependent for drug movement across membranes?
What type of transport mechanism is least energy-dependent for drug movement across membranes?
Signup and view all the answers
What is the impact of poorly water-soluble drugs on absorption?
What is the impact of poorly water-soluble drugs on absorption?
Signup and view all the answers
Which type of drug transport mechanism primarily deals with foreign substances in the body?
Which type of drug transport mechanism primarily deals with foreign substances in the body?
Signup and view all the answers
Which drug complex formation hinders absorption when taken with food?
Which drug complex formation hinders absorption when taken with food?
Signup and view all the answers
How does concentration gradient affect passive diffusion of drugs?
How does concentration gradient affect passive diffusion of drugs?
Signup and view all the answers
What factors affect the rate of dissolution of a drug?
What factors affect the rate of dissolution of a drug?
Signup and view all the answers
What does the apparent volume of distribution (V) describe?
What does the apparent volume of distribution (V) describe?
Signup and view all the answers
Which statement is true regarding poorly soluble and slowly absorbed drugs?
Which statement is true regarding poorly soluble and slowly absorbed drugs?
Signup and view all the answers
How does reducing the particle size affect drug absorption?
How does reducing the particle size affect drug absorption?
Signup and view all the answers
What happens after the drug dissolves in the aqueous gastrointestinal contents?
What happens after the drug dissolves in the aqueous gastrointestinal contents?
Signup and view all the answers
What is a significant effect of the compression force used in tablet manufacture?
What is a significant effect of the compression force used in tablet manufacture?
Signup and view all the answers
Which drug's amount in the tablet can be halved by microfining its particle size?
Which drug's amount in the tablet can be halved by microfining its particle size?
Signup and view all the answers
Which factor does NOT contribute to differences in bioavailability?
Which factor does NOT contribute to differences in bioavailability?
Signup and view all the answers
What does pharmacokinetics primarily study?
What does pharmacokinetics primarily study?
Signup and view all the answers
Which component of biological membranes contributes to their impermeability?
Which component of biological membranes contributes to their impermeability?
Signup and view all the answers
What primarily determines the rate of transport for lipid-soluble drugs?
What primarily determines the rate of transport for lipid-soluble drugs?
Signup and view all the answers
Which of the following best describes the organization of biological membranes?
Which of the following best describes the organization of biological membranes?
Signup and view all the answers
What role do glycoproteins play in biological membranes?
What role do glycoproteins play in biological membranes?
Signup and view all the answers
What is the significance of the lipid : water partition coefficient for a drug?
What is the significance of the lipid : water partition coefficient for a drug?
Signup and view all the answers
What determines the pharmaceutical response intensity at a drug's site of action?
What determines the pharmaceutical response intensity at a drug's site of action?
Signup and view all the answers
Which of the following correctly describes the composition of a biological membrane?
Which of the following correctly describes the composition of a biological membrane?
Signup and view all the answers
Which statement accurately describes the nature of the blood-brain barrier (BBB)?
Which statement accurately describes the nature of the blood-brain barrier (BBB)?
Signup and view all the answers
Which transporters contribute to restricting drug passage across the placenta?
Which transporters contribute to restricting drug passage across the placenta?
Signup and view all the answers
What primarily affects the extent of plasma protein binding of drugs?
What primarily affects the extent of plasma protein binding of drugs?
Signup and view all the answers
Which of the following drugs is least likely to be bound to plasma proteins?
Which of the following drugs is least likely to be bound to plasma proteins?
Signup and view all the answers
How does the concentration of a drug influence plasma protein binding?
How does the concentration of a drug influence plasma protein binding?
Signup and view all the answers
What role does the flow of cerebrospinal fluid (CSF) play in drug exit from the brain?
What role does the flow of cerebrospinal fluid (CSF) play in drug exit from the brain?
Signup and view all the answers
Which type of drugs tends to bind to plasma albumin?
Which type of drugs tends to bind to plasma albumin?
Signup and view all the answers
What factor can significantly alter the protein binding percentages of drugs?
What factor can significantly alter the protein binding percentages of drugs?
Signup and view all the answers
Study Notes
Pharmacokinetics
- Pharmacokinetics is the quantitative study of drug movement in, through, and out of the body.
- The intensity of drug response is determined by drug concentration at the site of action.
- Pharmacokinetic properties influence administration route, dose, onset latency, peak action time, duration, and frequency.
- All pharmacokinetic processes involve drug transport across biological membranes.
Biological Membranes
- Biological membranes are bilayers (approximately 100 Å thick) of phospholipid and cholesterol molecules.
- Polar groups (e.g., glyceryl phosphate) are oriented at opposite membrane surfaces.
- Nonpolar hydrocarbon chains are embedded within the membrane core.
- This structure creates high electrical resistance and impermeability to many substances.
Absorption
- Absorption is the movement of a drug from its site of administration into the bloodstream.
- Drug form, concentration, surface area, blood flow, and other factors impact absorption rates.
- Lipid-soluble drugs are absorbed more efficiently than water-soluble ones.
Distribution and Storage
- Distribution involves drug movement from the blood to tissues.
- Drug concentration at the site of action is influenced by blood flow distribution and binding to proteins in the blood or tissues.
- Drug storage locations depend on drug characteristics and tissue properties.
Excretion
- Excretion is drug elimination from the body.
- Drug removal occurs via various routes including urine, bile, feces, sweat, and saliva.
- Drug metabolism (biotransformation) in the liver can alter drug structure and enhance excretion.
Biotransformation
- Biotransformation is metabolic modification of drugs in the body.
- This process usually occurs in the liver.
- It alters drug properties, increasing water solubility, facilitating excretion.
Influence of pH
- Weak electrolytes (e.g., weak acids and bases) exist in ionized and unionized forms.
- The proportion of ionized and unionized forms is influenced by pH.
- Drugs' ionization can impact their absorption and distribution.
- The degree of ionization affects how well a drug can cross a membrane.
Passive Diffusion
- Passive diffusion is the most common mechanism for drug transport across membranes.
- In this process, drugs move from high to low concentration. This movement requires no energy from the body.
Filtration
- Filtration involves drug passage through aqueous pores.
- This process is influenced by hydrostatic or osmotic pressure that determines the rate of filtration.
- Drugs with molecular weights larger than pore diameters are not filtered.
Specialized Transport
- Specialized transport mechanisms include carrier-mediated transport and vesicular transport.
- Carrier-mediated transport employs proteins (carriers or transporters).
- Vesicular transport involves endocytosis and exocytosis—processes that engulf or release substances via vesicle formation.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
This quiz explores the fundamental concepts of pharmacokinetics, including drug absorption and the role of biological membranes. Understand how drug movement is influenced by various factors and the structure of membranes. Test your knowledge on how these processes impact drug efficacy and administration.
