Ticket 43

1. The combined action of medicinal substances. Synergy. Antagonism. Antidote.

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

Synergy - 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- reduction or complete elimination of the pharmacological effect of one medicinal substance 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 - occurs as a result of 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 - arises 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. Antiparkinsonian drugs. Classification. Mechanism of action. Indications for use. Side effects. Contraindications Comparative evaluation of drugs.

Antiparkinsonian drugs - drugs used in Parkinson's disease, tremor palsy in old age, and with complications of drug therapy.

Classification:

1. Drugs that activate dopaminergic effects

1.The precursor to dopamine is levodopa

2. Drugs that stimulate dopamine receptors (dopaminomimetics) - bromocriptine, ropinirole.

3 monoamine oxidase B inhibitors - selegiline

2. Means that inhibit glutamatergic effects - midantan.

3. Agents that inhibit the cholinergic effect - cyclodol.

Mechanism of action: in parkinsonism, the dopamine content in the basal ganglia is reduced, the interaction of acetylcholine and dopamine is shifted towards the predominance of cholinergic activity. Alignment of the interaction of 2 mediators is achieved by the use of central anticholinergics, or agents that activate the dopaminergic effect, or by the combined use of these drugs.

Indications: parkinsonism, spastic paralysis associated with damage to the extrapyramidal system.

Side effects: dyspepsia, orthostatic hypotension, mental disorders, movement disorders, arrhythmias.

Contraindications: glaucoma, atrial fibrillation, liver and kidney disease, hypertension.

Levodopa, a precursor of dopamine, penetrates the BBB, where it is converted into dopamine. It especially affects hypokinesia, decreases rigidity and tremor.

The most effective remedy. Action in a week. There are many side effects, they decrease with dose reduction.

Bromocriptine - a stimulant of dopamine receptors, reduces prolactin and growth hormone, side effects are often manifested.

Midantan - blocks glutamate receptors, has a beneficial effect on the substantia nigra (decreases in calcium in the cells); causes hypokinesia. The action develops in 1-2 days. There are fewer side effects.

Cyclodol - reduces movement disorders (damage to the extrapyramidal system), effectively reduces tremor.