With repeated administration of drugs, their effect can either increase or decrease.
An increase in the effect may be associated with the accumulation of medicinal substances in the body or in individual organs - cumulation . It is material and functional.
Material cumulation- the medicinal substance is slowly excreted from the body and accumulates in it with repeated injections, reaching toxic amounts. To avoid, re-introduction should be administered after a significant part of the elimination or destruction of the previous dose. Functional cumulation- when the originally introduced substance is removed from the body, and the function of the organ or system, changed by it, has not yet been restored. If at this time to introduce a second dose of the drug, then its effect is much more pronounced and longer.
addictive- decrease in effect with repeated use of the drug. It may be associated with a decrease in the absorption of a substance, an increase in the rate of its excretion from the body, a decrease in the sensitivity of receptors.
addiction (addiction)) - an irresistible desire for re-admission. People have mental and physical. Mental - emotional discomfort without medication
Physical - when the drug is discontinued, a serious condition occurs associated with a disorder in the functions of organs and systems.
Idiosyncrasy- genetically determined hypersensitivity to any drug. It happens after the use of iodine preparations by pets,
Question 25 of the ticket: addiction to medicinal substances when they are re-introduced:
addictive(tolerance, lat. tolerantis - patience) is a decrease in sensitivity to the drug after its repeated administration, which requires an increase in dose in order to cause an effect of the same intensity that occurred after administration of a lower dose. addictive- this is a partial or complete loss of the therapeutic (therapeutic) effect with prolonged use of the drug without the phenomena of drug dependence, that is, the development of addiction. For example, with the introduction of herbal laxatives containing anthraglycosides (rhubarb root, buckthorn bark, hay leaves), the laxative effect decreases after a few weeks. Habituation is a general biological property that can also be observed in microorganisms after the use of small doses of chemotherapeutic drugs. It is possible to eliminate addiction both by increasing (within the available limits) the dose, and by replacing the drug or stopping its use for a while.
A rapid decrease in the effectiveness of a drug after repeated administration, which develops over a period of several minutes to one day, is called tachyphylaxis(from Greek tachys - fast and phylaxis - protection). An example of tachyphylaxis can be a decrease in the hypertensive effect of ephedrine. After the first injection of the drug, blood pressure rises; after repeated 2-3 injections with an interval of 20-30 minutes, the vasoconstrictive effect is significantly reduced. To a bowl accustoming to medicine develops slowly, within several weeks of constant reception. Sleeping pills (especially derivatives of barbituric acid), tranquilizers, narcotic analgesics, laxatives, etc. have the property of being addictive. Drugs similar in chemical structure can also be addictive (promedol, morphine). Mechanisms of tolerance are different . A widely known fact arsenophagy- the ability of "trained" animals to ingest large amounts of arsenic oxide without detrimental effects. Habituation in this case is due to the development of inflammatory processes in the mucous membrane of the digestive canal and a decrease in the absorption of the poison as a result. If arsenic oxide is administered parenterally to such an animal, even the smallest dose is lethal.
The most common cause of addiction is the induction of microsomal liver enzymes by the drug and the acceleration of its own metabolism. This mechanism predominates in the development of addiction to barbiturates. Tolerance to organophosphorus compounds is due to a decrease in the sensitivity of cholinergic receptors to acetylcholine. The cause of habituation may also be the phenomenon of autoinhibition, similar to the well-known phenomenon in biochemistry of the inhibition of an enzyme by a substrate. The essence of the phenomenon lies in the fact that in the case of an excess in the body of the drug, not one, but several molecules bind to the receptor. The receptor is "overloaded" and the pharmacological effect is much less. Tolerance should not be equated with drug dependence.
Dependence on drugs and other substances (addiction). In accordance with the conclusions of the WHO Expert Committee, drug dependence is a mental condition, sometimes even a physical one, which is the result of an interaction between a living organism and a drug substance with certain behavioral and other reactions, when the desire to take the drug is constant or occurs periodically in order to avoid the discomfort that occurs without accepting it.
addiction- this is a strong, sometimes insurmountable requirement for the systematic use of certain drugs and other drugs that cause euphoria (Greek eu - pleasant and phero - endure), to improve mood, improve well-being, and also eliminate unpleasant sensations that arise after the withdrawal of these drugs.
Means that cause addiction can be divided into the following groups: alcohol-barbiturate (ethyl alcohol, phenobarbital); canabina (marijuana, hashish); cocaine; ethereal solvents (toluene, acetone, carbon tetrachloride); drugs that cause hallucinations (LSD, mescaline, psilocybin); drugs derived from opium (morphine, codeine, heroin) and their synthetic substitutes (promedol, fentanyl).
Dependence on several substances at the same time is possible.
Distinguish between mental and physical dependence on drugs. According to the WHO definition, mental dependence is "a condition in which a drug causes a feeling of satisfaction and mental exaltation - a state of euphoria that requires periodic or continuous administration of a drug in order to obtain a sense of satisfaction in order to avoid discomfort"; physical dependence - an adaptive state characterized by intense physical disturbances after the cessation of taking a particular drug. These disorders, i.e. withdrawal syndrome(Latin abstinentia - abstinence; synonymous with withdrawal syndrome, deprivation) - a complex of specific signs of mental and physical disorders characteristic of a certain narcotic analgesic.
The mechanism of this phenomenon is due to the fact that, as a result of systematic administration, the substance is included in the biochemical processes occurring in the body.
As a result, the metabolism and functioning of tissues are altered. The body gradually adapts to such a state, creating a new, different from the usual, metabolic homeostasis. If the drug intake is stopped, the balance of biochemical processes is disturbed. There is a serious condition (abstinence) - various, often severe somatic disorders (possible death), - which is eliminated only with the resumption of the introduction of the substance.
The cells of the brain are most sensitive to changing conditions, which is why drug dependence is caused by drugs that affect the central nervous system. The systematic use of narcotic analgesics with the development of dependence is called drug addiction. Changes in the functions of the brain lead to the sequential development of states of euphoric sleep and abstinence. With increasing dependence, the euphoric phase is reduced, the sleep phase almost disappears, the withdrawal phase changes and deepens. The most severe picture of drug dependence develops when physical, mental dependence and tolerance are combined.
Ticket question 26: drug addiction:
drug addiction- a syndrome that develops with repeated long-term use of drugs and is manifested by a sharp deterioration in health or well-being when the drug is discontinued. The most well-known dependence is on psychotropic drugs, often associated with withdrawal, for example, with the withdrawal of opiates or psychostimulants. However, dependence on many other drugs, such as glucocorticosteroids, is known. In persons with neurotic, somatoform and anxiety-depressive disorders, with persistent insomnia, after prescribing sedative and hypnotic drugs, addiction can form (in about 10% of cases) - an attempt to stop taking it leads to an exacerbation of symptoms. Drug dependence is widespread when taking benzodiazepines, primarily due to the unreasonable duration of their intake: with their short-term use, the risk of dependence is reduced.
The withdrawal syndrome of psychopharmacological drugs can be considered as a variant of the withdrawal syndrome in drug addiction, but it has a number of significant differences. Closest to the withdrawal syndrome is the syndrome of tranquilizer withdrawal: in this case, manifestations of physical and mental dependence are observed, although mental dependence in the form of craving for the drug rarely occurs - more often there is a so-called psychological attachment. With the abolition of antidepressants, only physical dependence is present: a characteristic vegetative symptom complex takes place, and with the abolition of antipsychotics, physical dependence is also observed (vegetative symptom complex and extrapyramidal disorders) without mental dependence. Long-term use of antipsychotics and antidepressants usually also does not cause changes in drug tolerance.
Drug dependence is overcome by abrupt (in the case of mental dependence) or gradual withdrawal of the drug or by replacing the drug with a less addictive one.( Addiction(English) addiction- dependence, addiction, addiction), in a broad sense, - an obsessive need felt by a person for a certain activity. The term is often used for phenomena such as drug addiction, drug addiction, but now it is more applied to non-chemical, but psychological addictions, for example, behavioral, examples of which are: Internet addiction, gambling, shopaholism, psychogenic overeating, fanaticism, etc. .
In a medical sense, addictiveness is obsessive the need to repeat certain actions, accompanied, in case of a violation of the patient's usual schedule, clearly expressed physiological and psychological abnormalities, non-trivial behavior and other mental disorders.
Ticket question 27: the phenomenon of synergism and antagonism of medicinal substances:
synergy is a type of interaction in which the effect of a combination exceeds the sum of the effects of each of the substances taken separately. i.e. 1+1=3 . Synergism can relate to both desired (therapeutic) and undesirable effects of drugs. The combined administration of the thiazide diuretic dichlothiazide and the ACE inhibitor enalapril leads to an increase in the hypotensive effect of each of the drugs, which is used in the treatment of hypertension. However, the simultaneous administration of aminoglycoside antibiotics (gentamicin) and the loop diuretic furosemide causes a sharp increase in the risk of ototoxicity and the development of deafness.
SYNERGISM OF MEDICINES (from the Greek synergia - cooperation, assistance), simultaneous action in one direction of two or more. substances that provide a higher overall effect than the action of each of them separately. Medicines. Substances can act on the same elements (direct S. l. s.) or on different ones (indirect S. l. s.). An example of direct S. l. With. can serve as a drug. the action of chloralhydrite and alcohol, indirect - the expansion of the pupil with atropine and adrenaline. As a result of the joint action of synergists pharmacological. the effect happens unequal force that depends on properties of substances, their doses and features patol. state of the body. S. l is most fully expressed. With. with a combination of substances in small doses, as well as with a combination of substances acting on different systems.
With a combination of certain drugs. substances, you can get an increase in the action of one of them (for example, an increase in the narcotic effect of chloral hydrate with chlorpromazine). Such a phenomenon is called potentiation. When both substances affect the same body systems and in the same direction (eg, potentiation of barbiturate anesthesia with chlorpromazine), potentiation of cash. true. In contrast, with false potentiation, it will help. substance has no active pharmacological. action, but only weakens the decay or slows down the release of the main. substances (eg, prolongation of barbiturate anesthesia with chloracizine). Therefore, false potentiation is one of the forms of prolongation (long-term action)
The effect of the summation of the action of drugs is used in practical medicine to reduce the possible manifestation of undesirable side effects, since the lower the dose, the less likely the development of adverse events.
Antagonism(from the Greek anti-against, agon- fight) of drugs in combinations manifests itself in the weakening or complete disappearance of their pharmacotherapeutic action. In medicine, antagonism as a type of pharmacological incompatibility can be conditionally divided into physicochemical and physiological. Physico-chemical include the so-called competitive, physical and chemical antagonisms (pharmaceutical incompatibility); to physiological - direct and indirect (pharmacological incompatibility).
Physical antagonism in pharmacology is possible between adsorbents (activated carbon, proteins, bentonite) and active medicinal substances, the effect of which is excluded due to their adsorption on adsorbents.
In practice, physical and chemical antagonists are more often used as antidotes, or antidotes (from the Greek antidotos - antidote). So, in case of barium chloride poisoning, sodium sulfate can be used as an antidote; heavy metals are strongly bound and rendered harmless by unithiol, etc.
With the simultaneous use of several medicinal substances, it is possible to completely turn off or weaken the action of some substances by others.
This phenomenon is called pharmacological antagonism. It is considered to be based on the presence of competitive relations or changes in the background for the action of substances.
Like synergy, antagonism can be direct or indirect. In the first case, medicinal substances have the same object of action, and in the second, the objects are different.
For example, a pupil constricted by arecoline can be dilated with atropine or epinephrine.
Atropine and arecoline act through the same object (cholinergic nerves) and hence their antagonism is direct.
The opposite effect of arecoline and adrenaline is obtained due to the impact on different objects (adrenergic and cholinergic nerves), but directly related to the same function (pupil size), so their antagonism is indirect. Antagonists can act to the same extent (two-way antagonism) or in different, when the influence of one of them prevails over the other (one-sided antagonism).
Since the limiting stage of the pharmacological action is paralysis, paralyzing substances are unilateral antagonists in any combination. Exciting and depressing substances can act antagonistically either bilaterally or unilaterally, depending on the properties of the antagonists.
28 ticket question:sources of drugs :
These include minerals, vegetable raw materials, raw materials of animal origin, waste products of microorganisms, synthetic compounds
Mineral springs- these are purified various chemical compounds: iron, copper, iodine, manganese, bismuth, cobalt, sodium, etc.
Animal origin- these are preparations obtained from organs and tissues of animals: adrenaline, insulin, hormonal preparations of the adrenal glands, pituitary gland, enzyme preparations, poisons of snakes, spiders, bees (antibiotics of animal origin).
Herbal medicinal substances Fruits, flowers, leaves, bark, roots, rhizomes of various plants can be sources of medicinal substances. According to the chemical structure, these are different compounds:
Alkaloids (alcalos - alkali). These are nitrogenous alkali-like substances that can contain oxygen and be oxygen-free - caffeine, nicotine, atropine, strychnine, etc.
Glycosides are ester-like substances, which include the non-sugar content of aglycone and the sugar glycone. Such drugs are obtained from various types of foxglove, lily of the valley, Montenegrin, strophanthus, etc.
Resins are compounds insoluble in water (soluble in organic solvents). With alkalis, they form soap-like compounds - sabur.
gums - These are mucus and mucus-like substances containing carbohydrates. Hydrolysis gives sugars. In water, mucus acts envelopingly.
Fixed oils- castor, sunflower, linseed, etc.
Essential oils- volatile aromatic compounds: dill, caraway, mustard, cloves, mint, etc. (expectorant, emetic).
Tannins- nitrogen-free compounds with local action (oak bark, blueberries, sage).
Ticket question 29: Medication dosing sources:
Age. The body's sensitivity to drugs changes with age. Children and the elderly over 60 are more sensitive to the effects of drugs than middle-aged people.
Body mass. Children are prescribed a lower dose than adults of the drug, due to the fact that they have less body weight. And the greater the body weight of a person, the greater the dosage they are prescribed.
individual sensitivity. The same l / n can act differently on different people, even if it is the same dosage. The action of l / n may vary depending on the pathological state of the body. Some pharmacological agents exert their effect only in pathological conditions (for example, acetylsalicylic acid lowers body temperature only if it rises, cardiac glycosides clearly stimulate the activity of the heart only in heart failure)
Ticket question 30: complications of drug therapy:
Complications of drug therapy are called drug-induced changes in the properties and functions of organs and systems of the body, accompanied by unpleasant subjective sensations or objectively threatening the health or life of the patient. They are caused by side, toxic or non-specific effects of drugs.
A side effect is considered to be the action of a drug that has the same mechanism of occurrence as the main one, but is not desirable from a therapeutic point of view. There are no drugs that do not have side effects. Thus, the appointment of an adrenomimetic adrenaline hydrochloride as a bronchodilator causes tachycardia, an increase in blood pressure. A frequent side effect of chemotherapeutic agents is the suppression of the vital activity of not only the causative agent of an infectious disease, but also commensal microorganisms. When the vital activity of microorganisms sensitive to the drug is suppressed, species insensitive to it (cocci, bacteria, fungi) multiply intensively (drug dysbacteriosis, candidiasis).
Phytoncides - antibiotics of plant origin (onion, garlic, wild garlic, bird cherry, nettle, etc.)
Microorganisms are the producers of many medicinal substances: antibiotics, enzyme preparations, etc. Preparations of fungal origin are also widely used - antibiotics.
Synthetic medicinal substances- these are drugs that are obtained in the laboratory by chemical reactions: FOS, HOS, carbamates, antibiotics, sulfonamides, hormonal, enzymatic, etc.
Side effects become complications if they cause complaints of the patient or pose a threat to health or life. For example, in the treatment of bronchial asthma with atropine, dry mouth caused by it can reach such an extent that swallowing and/or speech becomes difficult. Such a degree of side effect is assessed as a complication of drug therapy and requires the adoption of measures aimed at eliminating this complication, in particular, drug withdrawal. These complications are dose-dependent, easily predictable, and their manifestations, most often, are of little severity. In order to prevent them, it is necessary, firstly, to use drugs with maximum selectivity of action. For example, relief of bronchospasm with a mixed adrenomimetic adrenaline is accompanied by an increase in blood pressure and tachycardia, but the non-selective beta-agonist izadrin causes only tachycardia, and the selective beta 2-agonist fenoterol (berotec) does not cause either an increase in blood pressure or significant tachycardia.
Complications of a toxic nature, most often, have a different mechanism of occurrence than the main action. For example, the inhibition of hematopoiesis that occurs during treatment with butadione is not due to the blockade of COX. Toxic complications are often the result of an overdose of drugs, including those due to material or functional cumulation with prolonged use of even therapeutic doses (chronoconcentration effect.). In this case, a predominant toxic lesion of one or a group of organs (systems) is usually observed, in connection with which neurotoxic, cardiotoxic, etc. are distinguished. LV action.
Among the adverse reactions when using drugs, the most common effects are due to their pharmacological properties when using the drug at a therapeutic dose. For example, flushing of the skin with nicotinic acid is a common and normal reaction, although it is an adverse reaction, or tricyclic antidepressants and chlorpromazine not only affect the central nervous system, but also cause dry mouth and double vision.
For some drugs, toxic complications cannot be avoided at all. For example, cytostatics not only inhibit the growth of tumor cells, but also damage all rapidly dividing cells and inhibit the bone marrow. Therefore, in addition to their direct effect, they naturally lead to leukopenia.
With an increase in the dose of drugs, the risk of adverse reactions increases, for example, leukopenia develops from taking cytostatics, and the sedative effect of antihistamines increases.
Diseases of the cardiovascular system are the leading cause of death in people, and hypertension plays a primary role in this. Therefore, millions of people are being treated for hypertension and coronary heart disease. For therapy, beta-blockers and calcium channel blockers are primarily used. During therapy, there are several variants of clinical forms of adverse reactions associated with the pharmacological activity of the drug. Beta-blockers, reserpine, methyldopa, clonidine cause depression. Therefore, propranolol (Inderal), which is especially often accompanied by depression, should not be used by people suffering from depression or who have suffered from it in the past. Atenolol and nadolol are less likely to cause these side effects. Fatigue is often caused by beta-blockers, reserpine, methyldopa, and clonidine. Beta-blockers, methyldopa and a number of other drugs in the treatment of pathology of the cardiovascular system cause impotence and other types of sexual dysfunction. Often, when taking antihypertensive drugs, especially guanitidine, prazosin and methyldopa, dizziness is observed and, as a result, orthostatic hypotension with a sharp rise from a sitting or lying position. This can lead to falls and fractures. Among beta-blockers, labetalol most often causes dizziness, lowering blood pressure, which makes it a second-line drug in the treatment of uncomplicated hypertension. Beta-blockers can cause bronchospasm and provoke asthma attacks, so they should not be used in patients with bronchial asthma, chronic bronchitis, or emphysema.
With repeated use of drugs, their effect may change in the direction of both increasing and decreasing the effect.
The increase in the effect of a number of substances is associated with their ability to cumulation. Under material cumulation refers to the accumulation of a pharmacological substance in the body. This is typical for long-acting drugs that are slowly released or are persistently bound in the body (for example, some cardiac glycosides from the digitalis group). The accumulation of the substance during its repeated appointments can be the cause of toxic effects. In this regard, it is necessary to dose such drugs taking into account cumulation, gradually reducing the dose or increasing the intervals between doses of the drug.
There are known examples of the so-called functional cumulation , in which the effect, and not the substance, “accumulates”. So, with alcoholism, increasing changes in the function of the central nervous system can lead to the development of delirium tremens. In this case, the substance (ethyl alcohol) is rapidly oxidized and does not linger in the tissues. Only its neurotropic effects are summarized. Functional cumulation also occurs with the use of MAO inhibitors.
Reducing the effectiveness of substances when they are reused - tolerance (tolerance)) - observed when using a variety of drugs (analgesics, antihypertensives, laxatives, etc.). It may be associated with a decrease in the absorption of the substance, an increase in the rate of its inactivation and (or) an increase in the intensity of excretion. It is possible that addiction to a number of substances is due to a decrease in the sensitivity of receptor formations to them or a decrease in their density in tissues.
In case of addiction, to obtain the initial effect, the dose of the drug must be increased or one substance replaced with another. In the latter case, it should be taken into account that there is cross addiction to substances interacting with the same receptors (substrates).
A special kind of addiction is tachyphylaxis - addiction that occurs very quickly, sometimes after the 1st administration of the substance. Thus, ephedrine, when repeated with an interval of 10-20 minutes, causes a smaller rise in blood pressure than with the 1st injection.
To some substances (usually to neurotropic) with their repeated introduction, drug dependence develops. It is manifested by an irresistible desire to take a substance, usually in order to improve mood, improve well-being, eliminate unpleasant experiences and sensations, including those that occur during the abolition of substances that cause drug dependence. Distinguish between mental and physical drug dependence. When mental drug addiction stopping the administration of drugs (eg, cocaine, hallucinogens) causes only emotional discomfort. When taking certain substances (morphine, heroin) develops physical drug addiction . This is a more pronounced degree of dependence. Cancellation of the drug in this case causes a serious condition, which, in addition to sudden mental changes, manifests itself in various and often serious somatic disorders associated with the dysfunction of many body systems, up to death. This so-called withdrawal syndrome, or deprivation phenomena.
4. Interaction of drugs. Phenomena arising from the joint administration of two and / or more drugs.
Drug Interactions
Simultaneous administration of several drugs to a patient (polypharmacy) may be associated with the simultaneous treatment of several diseases. However, in the treatment of one disease, several drugs are often prescribed to increase the therapeutic effect.
There are pharmaceutical and pharmacological interactions of medicinal substances.
Pharmaceutical interaction is possible with the joint administration of drugs in one syringe, one system for drip administration. Pharmacological interactions are divided into pharmacokinetic and pharmacodynamic interactions.
With repeated use of L.V. there may be an increase or decrease in the pharmacological effect.
I. Cumulation - accumulation
1. Material cumulation - the accumulation of the substance itself. Happens
absolute cumulation- associated with the properties of L.V. occurs with prolonged use of substances that linger in the body for a long time and are very slowly excreted (barbature, SG, bromides, anticoagulants of an indirect type of action ...)
relative cumulation- occurs with liver or kidney disease, i.e. those organs that ensure the destruction and excretion of foreign substances. Correction of cumulation: - dose reduction, reduction in the number of doses
2. Functional cumulation – accumulation of “pharmacological effect”, i.e. the substance is excreted from the body quickly, but the changes that it caused in the body accumulate (anticoagulants of an indirect type of action, ethanol - "white tremens", sympatholytics, etc.)
II. addictive (tolerance = stability) - a decrease in the effect with prolonged use of L.V. (hypnotics, antihypertensives, analgesics, laxatives, NG, etc.). To obtain the effect of the necessary strength, an increase in the dose is required.
REASONS: a) decrease in the sensitivity of receptors; b) L.V. destruction acceleration; c) inclusion of compensatory reactions of the body d) depletion of endogenous metabolites involved in the pharmacodynamics of L.V. (NG, antidiabetic products of sulfonylurea).
To prevent addiction, it is rational to combine drugs with a different mechanism of action.
Tachyphylaxis - an acute form of addiction. Reducing the effect with repeated administration of L.V. at short intervals (ephedrine).
drug addiction - addiction, addiction. This irresistible desire to receive L.P. in order to eliminate physical or mental discomfort. Often characteristic of substances acting on the central nervous system (psychotropic drugs). Such drugs cause a feeling of mental comfort, good health and mood, euphoria, sometimes unusual mental reactions, hallucinations, a feeling of a surge of energy or a pleasant relaxation.
Allocate:
A) mental addiction – withdrawal of the drug causes emotional discomfort, mood deterioration, insomnia, the presence of unpleasant experiences and sensations;
B) physical addiction - cancellation is accompanied by disorders in the activity of various organs and systems, i.e. somatic disorders;
IN) abstinence - withdrawal syndrome, which develops as a result of a drop in the concentration of a narcotic substance in the blood. Accompanied by severe emotional and vegetative disorders up to death (anxiety, anxiety, sleep disturbance, nausea, vomiting, sweating, severe pain, lacrimation, diarrhea, fever and blood pressure, tachycardia, respiratory disorders, etc.)
Questions of computer tests on Pharmacology in lesson number 5 on the topic
Pharmacodynamics" - 2008
What is included in the concept of "pharmacodynamics"?
$Mechanisms of action.
The transformation of drugs in the body.
$Pharmacological effects.
distribution of drugs in the body.
$Localize the action.
$Action types.
The action of the medicinal substance that occurs at the site of application of the substance:
Resorptive.
$local.
The action of the drug substance that develops after its absorption:
Local.
$Resorptive.
When applied topically, the medicinal substance can have:
$local action.
$Direct action.
$Reflex action.
There are no correct answers.
A reflex action is an action that occurs when a drug stimulates receptors:
$ Afferent link of the reflex.
Central links of the reflex.
Efferent link of the reflex.
The main "targets" for the action of drugs:
structural proteins.
$ion channels.
$Specific receptors.
$Enzymes.
$Transport systems.
Specific receptors are:
Receptors that exist in the body for drugs.
$Receptors that exist in the body for endogenous ligands (mediators, hormones, etc.) with which medicinal substances can interact.
Internal activity is:
The ability of a substance to bind to specific receptors.
$The ability of a substance, when bound to specific receptors, to stimulate them and cause an effect.
The ability of a substance, when bound to specific receptors, to block them and cause an effect.
Affinity is:
$The ability of a substance to bind to specific receptors.
The ability of a substance to stimulate specific receptors.
The ability of a substance to produce an effect when interacting with specific receptors.
Substances with low internal activity are called:
Agonists-antagonists.
$Partial agonists.
Antagonists.
Full agonists.
Substances with high internal activity are called:
Agonists-antagonists.
partial agonists.
Antagonists.
$Full agonists.
Medicinal substances that excite some receptors and block others are designated as:
$Agonists-antagonists.
partial agonists.
Antagonists.
Full agonists.
The affinity (affinity) of a substance for receptors is characterized by:
elimination constant.
$Dissociation constant.
ionization constant.
Medicinal substances that have affinity and internal activity when interacting with specific receptors are called:
$Agonists.
Antagonists.
Agonists-antagonists.
Substances that have affinity for specific receptors, have no intrinsic activity, and interfere with the action of endogenous ligands and agonists on receptors are called:
$Antagonists.
partial agonists.
Agonists-antagonists.
Substances that, when interacting with specific receptors, cause maximum stimulation of receptors and a maximum response are called:
$Full agonists.
partial agonists.
Agonists-antagonists.
Antagonists.
Substances that, when stimulated by specific receptors, cause a reaction that is less than the maximum, are called:
full agonists.
$partial agonists.
Agonists-antagonists.
Antagonists.
The measure of drug activity is:
The amount of the half-maximal effect.
The magnitude of the maximum effect.
$The dose at which the substance produces half-maximal effect (ED50).
$Minimum effective dose of a substance.
$Average therapeutic dose of a substance.
$The dose at which the substance produces an effect equal to half of the maximum effect.
A dose equal to half the highest therapeutic dose of the substance.
$ is a measure of the activity of a substance.
It is a measure of the effectiveness of a substance.
The effectiveness of a medicinal substance can be judged:
The minimum effective dose.
$By maximum effect.
The dose at which the substance produces the maximum effect.
What term refers to unusual reactions to medicinal substances, usually associated with genetically determined enzymopathies and occurring during the first administration of substances?
Sensitization.
Tachyphylaxis.
$Idiosyncrasy.
Abstinence.
Addictive.
Idiosyncrasy is:
$ An unusual reaction of the body to the first administration of a medicinal substance.
Increasing the body's sensitivity to the drug.
Accumulation of the drug in the body.
Decreased effect with repeated administration of the drug.
What phenomena can occur with repeated administration of drugs?
$addictive.
$tachyphylaxis.
Potentiation.
$Drug addiction.
$cumulation.
Cumulation is:
Weakening of sensitivity to the medicinal substance with its repeated injections.
Increased sensitivity to the drug with repeated injections.
$ Strengthening of the action of a medicinal substance during its repeated administration, associated with the accumulation of a medicinal substance or its effect.
With repeated administration of medicinal substances, phenomena of addiction, drug dependence (addiction), cumulation, sensitization, followed by an allergic reaction, can be observed.
Addictive. The gradual weakening of the effect of a drug, forcing you to increase the dose of the drug or replace it with another one, is called addiction. Sometimes the cause of addiction can be explained by the accelerated metabolism of the drug in the body. To some medicinal substances addiction develops very quickly. For example, with repeated administration of ephedrine at short intervals (20-30 minutes), a significant decrease in the vasoconstrictor effect is observed after 2-3 injections. Such a phenomenon is called tachyphylaxis(from the Greek tachys - fast, phylax- is - protection). Addiction should not be equated with drug dependence (addiction). These are completely different concepts.
Drug addiction (addiction). This phenomenon is characterized by a strong, sometimes irresistible, desire for the systematic use of certain medicinal and other substances that cause euphoria (a kind of intoxication, a pleasant mood). Some substances that affect the psyche can cause euphoria: morphine, heroin, cocaine, alcohol, hashish, nicotine, phenamine, etc. Most of these substances are drugs, so their systematic use in connection with drug dependence is called addiction. Addiction is usually combined with addictive phenomena, so the euphoric dose of the drug is steadily increasing, which leads to chronic poisoning of the body. Patients with drug addiction are called drug addicts.
At present, the term "addiction" has been replaced by the concept "drug addiction ».
Such a definition shows that a drug (or other substance) in the process of its long-term use becomes a necessary component of the cells of the central nervous system, and the body becomes dependent on this substance. Indeed, prekratonne drug use leads to severe subjective sensations and dysfunction of the internal organs. These phenomena are called withdrawal symptoms(from Latin abstinentia - abstinence, deprivation), they quickly pass when the drug is resumed.
Distinguish between mental and physical drug dependence. Mental drug dependence is accompanied by unpleasant emotional phenomena, depressed mood, and sometimes aggressiveness. With physical dependence, the state of the drug addict is aggravated by dysfunctions of the cardiovascular system and other organs. Acute cardiovascular failure (collapse) may occur.
Cumulation. As a result of slow metabolism or excretion of drugs in the body, their cumulation may occur (lat. spilatio - accumulation). In such cases, repeated administration of drugs in therapeutic doses can lead to a significant increase in their concentration in the body (material cumulation) and poisoning.
There is also a functional cumulation, when the effect of the previous medication is preserved and enhanced with repeated doses. Cumulation can have a positive value, since it allows you to maintain the therapeutic effect of the drug for a long time with its rare introduction into the body.
For drugs that can cause cumulation, certain rules have been established for use (breaks in the treatment process, gradual dose reduction), and dispensing from pharmacies. Pharmacists should be aware of these rules and give appropriate explanations to patients, especially in cases where the medicine is dispensed without a prescription. Failure to follow the established rules can lead to severe poisoning.
Sensitization (increased sensitivity) of the body with repeated administration of drugs and the occurrence of allergic reactions are regarded as a pathological phenomenon and a complication of drug therapy.
Drug allergy is a peculiar reaction of the body to the repeated administration of the drug, regardless of its dose. And the basis of the allergic reaction are immune processes. There are allergic reactions of immediate (anaphylaxis) and delayed types, characterized by a variety of symptoms: urticaria and other skin rashes, impaired hematopoiesis, serum sickness, bronchial asthma, anaphylactic shock, etc.
The mutagenicity and carcinogenicity of some chemical compounds should be taken into account when creating new drugs. Mutagenicity - This is the ability of substances to cause permanent damage to the genetic apparatus of the germ cell, which is manifested in a change in the genotype of the offspring. Carcinogenicity is the ability of substances to cause the development of malignant tumors.