synonym: Dibasin, Regitine, Rogitine, etc.; joint venture. B) — adrenceptor blocking agent. 2- \-/га/ш-Толил-1Ч-(л£б?/? gya-oxy-feiil) — aminomethyl) - imidazoline a hydrochloride; C17Ii19N30 • HC1:
Abroad is issued also in the form of Methansulfonas natricum (Phentolami-ni methansulfonas).
White or slightly cream crystal powder of bitter taste. Phentolamine we will dissolve a hydrochloride in water a little, it is difficult — in alcohol. Phentolamine we will easily dissolve Methansulfonas natricum in water and alcohol. Water solutions have subacidic reaction (pH 4,5 — 5,5). In a dry form F. it is stable, in solutions and under the influence of light slowly decays.
T. blocks ah - and a2-adrenore-tseptory, weakens pressor effect of noradrenaline and others and-adrenomimetikov (see Adrenomime-tichesky means), perverts vasoconstrictive effect of adrenaline (see). Besides, F. slows down effect of serotonin (see), has histamine-like activity and strengthens motive and secretory activity went. - kish. path. Pressor action of the endogenous and exogenous catecholamines coming to blood blocks is more expressed, than the vasoconstriction caused by excitement of a sympathetic nervous system. It is similar to others and - to adreno-blockers, T. expands peripheral vessels (hl. obr. arterioles and and rekapillyara) also eliminates their spasms that is followed by improvement of blood supply of muscles, skin and mucous membranes. Decrease in the ABP (causes also pitch swarm especially at a pheochromocytoma), expands vessels of a small circle of blood circulation. Hypotensive effect F. is followed by tachycardia.
since it blocks presynaptic and - adrenoceptors and by that facilitates allocation a hole a drain a linden from these terminations. On r-adrenore-tseptory heart and other bodies F. does not work.
From intestines F. it is soaked up not completely, in an organism is exposed to biotransformation with formation of metabolites, to-rye are removed by kidneys. Apprx. 10% of the entered dose F. it is allocated with urine in not changed look.
Apply at frustration of peripheric circulation (an obliterating endarteritis, a Raynaud's disease, thromboembolisms), at treatment of trophic ulcers of extremities, inertly healing wounds, decubituses, freezing injuries, to the prevention of a necrosis in case of hit under skin of noradrenaline during its intravenous administration, and also in complex therapy of hypertensive crises and shock. At a pheochromocytoma F. apply to conducting diagnostic test and during an operational oncotomy.
Phentolamine the hydrochloride is appointed inside after food on 0,05 g by 3 — 4 times a day. If necessary the dose is increased to 0,5 g a day. Phentolamine Methansulfonas natricum in the form of freshly cooked 0,1 — 0,5% of solution is entered intramusculary or intravenously on 1 ml of 1 — 2 time a day. Course of treatment of 3 — 4 weeks. At shock and for stopping of hypertensive crises, and also for conducting diagnostic test at a pheochromocytoma and its removal of 0,5% solution of phentolamine of Methansulfonas natricum is entered intramusculary or intravenously on 1 ml.
Side effect F. it is shown by tachycardia, dizzinesses, swelling of a mucous membrane of a nose, a hyperemia and an itch of skin, nausea, vomiting, a diarrhea. At hypersensitivity or overdose the orthostatic collapse is possible, for the prevention to-rogo stay of the patient in horizontal position to the current of i1/2 — 2 hours after an injection of drug is recommended.
It is contraindicated at coronary insufficiency and crushing organic lesions of cardiovascular system.
Forms of release: phentolamine a hydrochloride in tablets on 0,025 g; phentolamine Methansulfonas natricum in ampoules on 0,005 g. Storage: in the place protected from light.
See also Adrenolitichespy means, Antihypertensives, Vasodilators.
M. Ya. Melzobs.