FIZOSTIGMYN (Physostigminum; a synonym Eserinum) — anti-cholinesterases-noye means; the alkaloid received from so-called calabar beans — seeds of a plant of a fizostigm poisonous (Physostigma venenosum), the family of bean (Leguminosae) growing in rainforests Zap. Africa.
In medical practice apply physostigmine salicylate (Physostigmi-ni Salicylas; synonym: Physostigminum salicylicum, Eserini Salicylas, Phy-sostigmine Salicylate; GFH, cn. A). Trimetil - metilkarbamoiloksi-thetas-ra-gidropirrola salicylate;
Colourless brilliant prismatic crystals. From effect of light and air are painted in red color. Difficult rastvorima in water, are alcohol-soluble, a little ether-soluble; pier. weight (weight) 413,5; t°njl 184 — 187 °. Solutions of drug prepare ex tempore aseptically or subject tindallizations (see).
T. inhibits cholinesterase (see) by formation of a covalent bond between its carbamile group and a hydroxyl of serine in an active center of this enzyme. However activity of cholinesterase is easily recovered due to bystry hydrolysis of its complex with physostigmine. In this regard F. carry to reversible inhibitors of cholinesterase. At introduction F. in the dose which is completely inhibiting activity of cholinesterase, duration of its inactivation does not exceed the 6th hour.
Interfering with hydrolysis of acetylcholine (see), T. strengthens and prolongs its effects. M-holinomime-ticheskoye action F. it is shown by increase in a tone and sokratitelny activity of smooth muscles of eyes, bronchial tubes, went. - kish. path, bilious and uric ways, uterus. In therapeutic doses F. causes bradycardia, reduces contractility of a myocardium, slows down atrioventricular conductivity, lowers the ABP, facilitates transfer of excitement in neuromuscular sinap-
of Sakha and vegetative gangliya. However at introduction in high doses F. can cause tachycardia, hypertensia that is connected with excitement sympathetic gangliyev and strengthening of secretion of adrenaline (see) from adrenal glands (nicotinosimilar effect), and oppresses neuromuscular transmission up to development of the neuromuscular block.
Along with antikholinesterazny action in rather high doses F. can exert a direct impact on holinoretseptor. Affects as well the presynaptic cholinergic terminations, causing simplification of release of a ltsetilkholin from nervous the term leu. T. it is well soaked up at different ways of introduction. It is rather quickly metabolized in an organism and allocated with kidneys of hl. obr. in the form of metabolites. Duration of action F. at hypodermic introduction makes apprx. 2 hours.
Apply hl. obr. in eye practice as a miotoc (see) for decrease in intraocular pressure. Enter into a conjunctival sac on
1 — 2 drops 0,25 — 1% of solution of 1 — 4 time a day. The effect occurs usually in 5 — 15 min. and proceeds apprx. 2 — 3 hour. At glaucoma F. is more effective, than Pilocarpinum. However owing to sharp reduction of muscles of an iris F. sometimes causes pain in an eye. Drug is used also for stopping of an atropinic coma, at a myasthenia and paresis of intestines, appointing it according to these indications on 0,5 — 1 ml of 0,1% of solution under skin.
The highest doses for adults under skin: one-time 0,0005 g, daily 0,001 g.
At overdose or hypersensitivity to F. there can be hypersalivation, nausea, strengthening of a vermicular movement, diarrhea, a frequent urination, muscular fibrillations. In this case as antagonists use the atropine and other holinoblokiruyu-shchy means possessing the central and peripheral action.
It is contraindicated at hyperkinesias, bronchial asthma, stenocardia, arrhythmias of heart, atherosclerosis. T. strengthens action of stimulators of c. N of page, napr, strychnine, Corazolum, etc. It is necessary to avoid appointment F. at pregnancy.
Form of release: powder. Storage: in well corked banks of orange glass in the place protected from light. Solutions release in bottles of orange color.
See also Antikholinesterazny means.
Bibliogrgolikov S. N. and P about-zengart V. I. Cholinesterases and antikholinesterazny substances, page 76, etc.,
L., 1964; Prozorovsky V. B. and With and in and t of e e in N. V. Neantikholin-esteraznye mechanisms of action of antikholinesterazny means, page 86, etc., L., 1976; International encyclopedia of pharmacology and therapeutics, sect. 13, v. 1. Anticholinesterase agents, ed. by A. G. Karc-zmar, Oxford a. o., 1970. C.H. Golikov.