Description of the medicine: Caffeine (Coffeinum)

COFFEE (Coffeinum). 1, 3, 7-Trimethylxanthine.

Synonyms: Caffeine, Guaranin, Theinum.

The alkaloid contained in the leaves of tea (about 2%), coffee seeds (1 - 2%), cola nuts. It is also obtained synthetically.

White silky needle-like crystals or white crystalline powder of bitter taste, odorless. Slowly soluble in water (1:60), easily - in hot (1: 2), hardly soluble in alcohol (1:50). Solutions have a neutral reaction; Sterilized at + 100 ° C for 30 minutes.

By its structure and pharmacological properties, caffeine is close to theobromine (see) and theophylline (see); All three alkaloids belong to the group of methylxanthines.

Of these alkaloids, the most powerful excitatory effect on the central nervous system is provided by caffeine. Less effect has theophylline, even less - theobromine; Theophylline strongly stimulates cardiac activity and diuresis, less theobromine, then caffeine. In connection with these differences in the effect of action, caffeine is used primarily as a stimulant of the central nervous system, and theophylline and theobromine are used as cardiovascular agents.

Physiological features of the effect of caffeine on the central nervous system were studied by IP Pavlov and his co-workers, who showed that caffeine enhances and regulates the processes of excitation in the cerebral cortex; In appropriate doses, it enhances the positive conditioned reflexes and increases the motor activity. Stimulating action leads to increased mental and physical performance, reducing fatigue and drowsiness. Large doses can, however, lead to the depletion of nerve cells. The effect of caffeine (as well as other psychostimulants) largely depends on the type of higher nervous activity; Dosing of caffeine should therefore be performed taking into account the individual characteristics of nervous activity. Caffeine weakens the effect of sleeping pills and narcotics, increases the reflex excitability of the spinal cord, excites the respiratory and vasomotor centers. Cardiac activity under the influence of caffeine increases, myocardial contractions become more intense and more frequent. In the case of collateral and shock states, blood pressure under the influence of caffeine increases, with normal arterial pressure, no significant changes are observed, since simultaneously with the excitation of the vasomotor center and the heart under the influence of caffeine, the blood vessels of skeletal muscles and other areas of the body expand (vessels of the brain, heart, kidneys ), But the vessels of the abdominal organs (except the kidneys) narrowed. Diuresis under the influence of caffeine is somewhat strengthened, mainly due to a decrease in the reabsorption of electrolytes in the renal tubules.

Caffeine lowers the aggregation of platelets.

Under the influence of caffeine, stimulation of the secretory activity of the stomach occurs.