Physostigma venenosum – Physostigmine venenosum
Tropical evergreen leguminous (Fabaceae). It grows in Africa. For medical purposes use the seeds of plants (Calabar bean), of which emit physostigmine (ezerin).
Chemical composition physostigma venenosum
The seeds (ʙoʙax) plant contains alkaloids - eserine, ezeramin, ezeridin, genezerin, izofizostigmin and fizovenin, and fatty oils and, phytosterol and stigasterin.
Pharmacological properties physostigma venenosum
Ezerin (physostigmine) It is the main active ingredient of the plant, defining its pharmacological properties. It relates to alkaloid compounds anticholinesterase, the specificity of the pharmacological action of which is to inactivation or inhibition of cholinesterase activity, whereby acetylcholine is prevented from a full and rapid hydrolytic cleavage. Therefore acetylcholine, isolated in the cholinergic synapses, under normal physiological function is not destroyed, and, opposite, stored therein and provides pharmacological effects, characteristic of acetylcholine and cholinomimetic substances, excitatory cholinergic function systems.
Application fiziostigmina in laboratory animals is accompanied by stimulation of M-cholinergic system, which corresponds to the excitation of postganglionic fibers of the parasympathetic nerves, characterized by constriction of the pupil, ʙradikardiej, increased secretion of salivary and other glands, increased intestinal motility and contractility of the uterus. Besides, Physostigmine has a H-nicotinic properties, facilitating the transfer of excitation in the autonomic ganglia and skeletal muscle, as well as stimulating the functional activity of the cells of the adrenal medulla oblongata and centers.
The use of drugs in medicine physostigma venenosum
Anticholinesterase physostigmine salicylate properties are widely used in ophthalmic practice. Physostigmine is used mainly for pupil constriction and reduction of intraocular pressure in glaucoma.
Due to the fact that the effect of physostigmine on obscherezorbtivnoe pupil is expressed rather weakly, The drug is usually administered in the conjunctival sac of 1-2 drops 0.25-1 % solution 2-6 times a day. Constriction of the pupil after about 5-10 minutes and lasts for 2-3 hours or more. Since physostigmine sometimes causes pain in the eye due to the strong contraction of the iris, the drug is recommended for acute glaucoma only in cases, when pilocarpine not effective enough. Eye drops are best to cook on 2 % boric acid. Good results are obtained with a combination of pilocarpine fizostigmiia.
Physostigmine is used in various diseases of the neuromuscular system (paresis, Paralič, polio, siringomielija, multiple sclerosis and others.) as 0,1 % solution for injection under the skin.
Contraindications. Physostigmine Contraindications giperkinezah, epilepsy, asthma, hypertensive disease, atherosclerosis and heart disease.
Formulations, Dosage and administration of drugs physostigma venenosum
Physostigmine salicylate (Physostigmine salicylas)-bestsvetny crystalline powder, redden. Higher doses fizostigmiia for adults under the skin: single 0,0005 g, daily 0,001 g.
