THEOPHYLLINE (Theophyllinum; synonym: Asmafil, Theocin, Theofin etc.; GFH, joint venture. B) — vasodilating, broncholitic and diuretic; the alkaloid which is contained in tea leaves and seeds of a coffee tree. For the medical purposes T. receive from these vegetable sources and a synthetic way. 1,3 Dimethylxantine; With 7 H 8 N 4 O 2 - H 2 O:
Inodorous white crystal powder. We will dissolve in a cold water a little (1: 180), 95% alcohol, ether and chloroform, we will easily dissolve in hot water (1: 85) and hot 95% alcohol, we will dissolve in to-takh and alkalis; t°pl 271 — 274 °; pier. weight (weight) 198,18.
On pharmacological action it is close to to caffeine (see) and to other alkaloids from group of derivatives of purine. Increases contractility of a myocardium, increases cordial emission, speeds up a rhythm of cordial reductions. Due to strengthening of cardiac performance increases the need of a myocardium for oxygen. Increases a coronary and renal blood stream. Causes broncholitic effect by reduction of a tone of smooth muscles of bronchial tubes. Has diuretic effect of hl. obr. due to decrease in a reabsorption of ions of sodium and chlorine in renal tubules, and also partially — due to strengthening of a renal blood-groove. Stimulates c. N of page. On influence on heart, a tone of bronchial tubes and a mocheotdeleniye is more active, than caffeine and theobromine (see). On activity concerning c. the N of page concedes to caffeine.
Mechanism of action T. and other alkaloids of a purine row it is caused by inhibition of enzyme of the phosphodiesterase participating in transformation of cyclic AMF (tsAMF) into AMF. Owing to inhibition of phosphodiesterase connect the main effects with accumulation of tsAMF in cells of various fabrics (stimulation of cordial activity, relaxation of smooth muscles of vessels and bronchial tubes, excitement of c. N of page) T. and other puri-vovy alkaloids. It is established that sensitivity of phosphodiesterase in cells of different fabrics to separate purine alkaloids and including to T. it is not identical. It, apparently, caused unequal activity of T. and close to it on a structure of purine derivatives concerning various bodies.
T. it is well soaked up from went. - tshsh. path. After intake collects in blood in the maximum concentration within 1 hour. Level of therapeutic concentration of T. in blood — to 5 mkg/ml. At concentration of T. signs of its toxic action develop in blood of 20 mkg/ml and above. In blood T. for 50 — 60% communicates proteins of plasma. The period of his semi-life in blood at adults apprx. 3,5 hours, at children — apprx. 8 — 9 hours. At cirrhosis and a fluid lungs the period of circulation of T. in blood it is extended till 60 o'clock. T. the hl is metabolized. obr. in a liver. Its main metabolites are 1,3-dimethyl uric to - that, 3 methylxanthine and 1-methyl-uric to - that. One of metabolites of T. (3 methylxanthine) possesses the expressed broncholitic action and on activity in this respect concedes to T. only by 1,5 — 2 times, but T. Vyvoditsya from an organism of T circulates in blood much longer, than. preferential in the form of metabolites and only partially (to 10%) — in not changed look.
Apply T. hl. obr. as broncholitic cure for bronchial asthma and other diseases of the lungs proceeding with increase in a tone of bronchial tubes. For this purpose T. often appoint in a combination with other antispasmodics. Besides, T. sometimes apply as diuretic at the developments of stagnation caused by a heart and renal failure. However by efficiency of T. concedes to furosemide (see), to a dichlothiazide (see) and to other modern diuretics.
Appoint inside the adult on 0,1 — 0,2 g 3 — 4 times a day. At bad portability of T. it is possible to appoint rektalno (in the form of candles) in the same doses. To children at the age of 2 — 4 years of T. appoint 0,01 — 0,04 g, 5 — 6 years — on 0,04 — 0,06 g, 7 — 9 years — on 0,05 — 0,075 g, 10 — 14 years — on 0,05 — 0,1 g to reception. To children up to 2 years of T. do not appoint.
The highest doses for adults inside and rektalno: one-time 0,4 g, daily 1,2 g.
Side effect T. it is shown by heartburn, nausea, vomiting, ponosa, a headache. At overdose of T. can cause convulsive attacks.
Forms of release: powder, candles on 0,1 and 0,2 g Besides, T. is a part Euphyllinum (see), and also the combined tablets «Theophedrinum» and «Antastman». Store in well corked container protecting from effect of light.
Bibliography: Mashkovsky M. D. Pharmaceuticals, h, 1, with, 391, M., 1977; The pharmacological basis of therapeutics, ed. by A „G. Gilman a. o., N. Y., 1980.
V. K. Muratov.