Ticket 19

1. The combined effect of drugs. Synergy. Antagonism. Antidote.

With the combined use of medicinal substances, their effect can be enhanced (synergism) or weakened (antagonism)

Synergy is the unidirectional action of two or more medicinal substances in which a pharmacological effect develops that exceeds the effects of each substance separately. Synergy occurs in two forms: summation and potentiation.

Antagonism is a decrease or complete elimination of the pharmacological effect of one drug by another when used together. Used in the treatment of poisoning and to eliminate unwanted reactions to a drug.

Types of antagonism: direct functional, indirect functional, physical, chemical.

Direct functional - Example: competitive antagonism of beta blockers, antimetabolites.

Indirect functional antagonism - develops in those cases when medicinal substances show the opposite effect on the work of an organ and, at the same time, their action is based on different mechanisms. Example: aceclidine, papaverine.

Physical - arises from the adsorption of one drug on the surface of another, resulting in the formation of inactive or poorly absorbed complexes. It is used to treat poisoning.

Chemical - occurs as a result of a chemical reaction between substances as a result of which inactive compounds are formed. These substances are called antidotes.

If, as a result of the combined use of drugs, a pronounced therapeutic effect is achieved, then the combination of drugs is considered rational and therapeutically appropriate, if undesirable effects develop, such combinations are considered irrational, therapeutically inexpedient (drug incompatibility)

2.Sleeping drugs. Classification by chemical structure. Mechanism of action. Side effects. Contraindications Comparative evaluation. Possibilities for the development of addiction.

Sleeping pills are medicinal substances that cause a person to experience a state close to natural sleep.

It is used for insomnia to facilitate falling asleep and to ensure a normal duration of sleep.

Classification:

I. hypnotics with a non-narcotic type of action:

1. Benzodiazepine receptor agonists:

1) Derivatives of benzodiazepine - short-acting triazolam,

medium duration of action-lorazepam, lorazepam, nitrazepam, long-acting-phenazepam, diazepam.

2) Preparations of different chemical structures: zopiclone, zolpidem, zaleplon.

2. Agonists of melatonin receptors (synthetic analogs of melatonin): ramelteon, melaxen.

3. Blockers of H1 - histamine receptors (ethanolamine derivative): doxylamine, donormil.

II.Sleeping drugs with a narcotic type of action:

1. Heterocyclic compounds (derivatives of barbituric acid): phenobarbital, sodium ethaminal.

2. Compounds of the aliphatic series: chloral hydrate, sodium oxybutyrate, bromized.

The mechanism of action of benzodiazepine derivatives and drugs of different chemical structure: They interact with benzodiazepine receptors, increase their sensitivity to GABA, melatonin receptor agonists are analogous to the hormone melatonin, the main function of which is the regulation of biological rhythms. The drugs stimulate melatonin receptors, histamine receptor blockers block these receptors and cholinergic receptors in the reticular formation and enhance inhibitory processes, aliphatic compounds are converted in the central nervous system into an inhibition mediator - GABA.

Indications: insomnia due to anxiety, stress; neuroses, removal of seizures, alcoholic obsession.

Side effects: drowsiness, lethargy, the phenomenon of recoil, hypoventilation, impaired coordination, decreased blood pressure, irritability, depression, allergic reactions.

Contraindications: drug addiction, myasthenia gravis, respiratory, renal failure, hepatitis, pregnancy, blood diseases. Long-term use of barbiturates causes mental and physical drug dependence.

Benzodiazepine derivatives have a sedative, hypnotic, anticonvulsant and muscle relaxant effect, in small doses they have an anti-anxiety and sedative effect, in high doses - hypnotic, anticonvulsant. shorten the phase of REM sleep, but to a lesser extent than derivatives of barbituric acid.

Preparations of different chemical structures have a selective hypnotic effect, do not cause recoil syndrome, and do not disrupt the physiological structure of sleep.

Agonists of melatonin receptors have an adaptogenic sedative hypnotic effect, normalize circadian rhythms, addiction and drug dependence do not develop, there is no recoil phenomenon, and do not disturb the physiology of sleep.

Blockers of H-histamine receptors in terms of effectiveness, the action is similar to benzodiazepine derivatives, has a daytime aftereffect, low toxicity.

Heterocyclic compounds in high doses cause anesthesia, induction of liver enzymes, material accumulation, post-somnic effect, with prolonged use - addiction, drug dependence.