Pharmacokinetics is:
The study of biological and therapeutic effects of drugs
The study of absorption, distribution, metabolism and excretion of drugs
The study of mechanisms of drug action
The study of methods of new drug development
What does “pharmacokinetics” include?
Complications of drug therapy
Drug biotransformation in the organism
Influence of drugs on metabolism processes
Influence of drugs on genes
Pharmacological effects of drugs
Unwanted effects of drugs
Chemical structure of a medicinal agent
Distribution of drugs in the organism
The main mechanism of most drugs absorption in GI tract is:
Active transport (carrier-mediated diffusion)
Filtration (aqueous diffusion)
Endocytosis and exocytosis
Passive diffusion (lipid diffusion)
What kind of substances can’t permeate membranes by passive diffusion?
Lipid-soluble
Non-ionized substances
Hydrophobic substances
Hydrophilic substances
A hydrophilic medicinal agent has the following property:
Low ability to penetrate through the cell membrane lipids
Penetrate through membranes by means of endocytosis
Easy permeation through the blood-brain barrier
High reabsorption in renal tubules
What is implied by «active transport»?
Transport of drugs trough a membrane by means of diffusion
Transport without energy consumption
Engulf of drug by a cell membrane with a new vesicle formation
Transport against concentration gradient
What does the term “bioavailability” mean?
Plasma protein binding degree of substance
Permeability through the brain-blood barrier
Fraction of an uncharged drug reaching the systemic circulation following any route administration
Amount of a substance in urine relative to the initial doze
The reasons determining bioavailability are:
Rheological parameters of blood
Amount of a substance obtained orally and quantity of intakes
Extent of absorption and hepatic first-pass effect
Glomerular filtration rate
Pick out the appropriate alimentary route of administration when passage of drugs through liver is minimised:
Oral
Transdermal
Rectal
Intraduodenal
Which route of drug administration is most likely to lead to the first-pass effect?
Sublingual
Intravenous
Intramuscular
What is characteristic of the oral route?
Fast onset of effect
Absorption depends on GI tract secretion and motor function
A drug reaches the blood passing the liver
The sterilisation of medicinal forms is obligatory
Tick the feature of the sublingual route:
A drug has a pretty fast absorption
A drug is exposed to gastric secretion
A drug is exposed more prominent liver metabolism
A drug can be administrated in a variety of doses
Pick out the parenteral route of medicinal agent administration:
Inhalation
Parenteral administration:
Cannot be used with unconsciousness patients
Generally results in a less accurate dosage than oral administration
Usually produces a more rapid response than oral administration
Is too slow for emergency use
What is characteristic of the intramuscular route of drug administration?
Only water solutions can be injected
Oily solutions can be injected
Opportunity of hypertonic solution injections
The action develops slower, than at oral administration
Intravenous injections are more suitable for oily solutions:
Correct statements listing characteristics of a particular route of drug administration include all of the following EXCEPT:
Intravenous administration provides a rapid response
Intramuscular administration requires a sterile technique
Inhalation provides slow access to the general circulation
Subcutaneous administration may cause local irritation
Most of drugs are distributed homogeneously.
Biological barriers include all except:
Renal tubules
Cell membranes
Capillary walls
Placenta
What is the reason of complicated penetration of some drugs through brain-blood barrier?
High lipid solubility of a drug
Meningitis
Absence of pores in the brain capillary endothelium
High endocytosis degree in a brain capillary
The volume of distribution (Vd) relates:
Single to a daily dose of an administrated drug
An administrated dose to a body weight
An uncharged drug reaching the systemic circulation
The amount of a drug in the body to the concentration of a drug in plasma
For the calculation of the volume of distribution (Vd) one must take into account:
Concentration of a substance in plasma
Concentration of substance in urine
Therapeutical width of drug action
A daily dose of drug
A small amount of the volume of distribution is common for lipophylic substances easy penetrating through barriers and widely distributing in plasma, interstitial and cell fluids:
The term “biotransformation” includes the following:
Accumulation of substances in a fat tissue
Binding of substances with plasma proteins
Accumulation of substances in a tissue
Process of physicochemical and biochemical alteration of a drug in the body
Biotransformation of the drugs is to render them:
Less ionized
More pharmacologically active
More lipid soluble
Less lipid soluble
Tick the drug type for which microsomal oxidation is the most prominent:
Lipid soluble
Water soluble
Low molecular weight
High molecular weight
Pick out the right statement:
Microsomal oxidation always results in inactivation of a compound
Microsomal oxidation results in a decrease of compound toxicity
Microsomal oxidation results in an increase of ionization and water solubility of a drug
Microsomal oxidation results in an increase of lipid solubility of a drug thus its excretion from the organism is facilitated
Stimulation of liver microsomal enzymes can:
Require the dose increase of some drugs
Require the dose decrease of some drugs
Prolong the duration of the action of a drug
Intensify the unwanted reaction of a drug
Metabolic transformation (phase 1) is:
Acetylation and methylation of substances
Transformation of substances due to oxidation, reduction or hydrolysis
Glucuronide formation
Binding to plasma proteins
Biotransformation of a medicinal substance results in:
Faster urinary excretion
Slower urinary excretion
Easier distribution in organism
Higher binding to membranes
Conjugation is:
Process of drug reduction by special enzymes
Process of drug oxidation by special oxidases
Coupling of a drug with an endogenous substrate
Solubilization in lipids
Which of the following processes proceeds in the second phase of biotransformation?
Acetylation
Reduction
Oxidation
Hydrolysis
Metabolic transformation and conjugation usually results in an increase of a substance biological activity:
In case of liver disorders accompanied by a decline in microsomal enzyme activity the duration of action of some drugs is:
Decreased
Enlarged
Remained unchanged
Changed insignificantly
Half life (t ½) is the time required to:
Change the amount of a drug in plasma by half during elimination
Metabolize a half of an introduced drug into the active metabolite
Absorb a half of an introduced drug
Bind a half of an introduced drug to plasma proteins
Half life (t ½) doesn’t depend on:
Biotransformation
Time of drug absorption
Concentration of a drug in plasma
Rate of drug elimination
Elimination is expressed as follows:
Rate of renal tubular reabsorption
Clearance speed of some volume of blood from substance
Time required to decrease the amount of drug in plasma by one-half
Clearance of an organism from a xenobiotic
The most rapid eliminated drugs are those with high glomerular filtration rate and actively secreted but aren’t passively reabsorbed:
Systemic clearance (CLs) is related with:
Only the concentration of substances in plasma
Only the elimination rate constant
Volume of distribution, half life and elimination rate constant
Bioavailability and half life
