NOVOKAINAMID (Novocainamidum; synonym: Amidoprocain, Cardiorytmin, Procainamidi Hydrochloridum, Pronestyl etc.; GFH, joint venture. B) — antiarrhythmic means. Beta Dietilaminoetilamida n-aminobenzoic to - you are a hydrochloride; With 13 H 21 N 3 O • HCl:
Inodorous crystal powder, white or white with creamy shade, we will very easily dissolve in water, it is easy — in alcohol, it is slightly soluble in chloroform, is almost insoluble on air. Like, weight (weight) 271,79; t ° pl 165 — 169 °. Water solutions are colourless, are stabilized by sodium metabisulphite (0,5%); pH of 10% of solution 3,8 — 5,0; solutions H. will sterilize at t ° 100 ° within 30 min.
On a chemical structure of N. it is close to to novocaine (see). Has antiarrhythmic and weak mestnoanesteziruyushchy properties. The mechanism of antiarrhythmic action is connected with membrane stabilizing action and the oppressing N.'s influence on energy balance of cells of a myocardium. Thereof N. reduces activity potassium-natriye-vogo of the pump, causing weakening of a flow of ions of Na + in a cell and increase in intracellular ion concentration of K+ in a myocardium that is followed by changes of its bioelectric activity — increase in an excitation threshold, increase in the effective refractory period and time of carrying out excitement. The N suppresses the ectopic centers of excitement in a cardiac muscle and exerts the direct oppressing impact on automatism of a sinus node owing to what there is an urezheniye of a cordial rhythm. Contractility of a myocardium under the influence of N. can decrease by 15 — 35%. The N is well soaked up in blood at different ways of introduction. The maximum level it in blood is noted in 1 — 1,5 hour after intake and in 15 — 60 min. after intramuscular introduction. N.'s concentration in blood decreases by 50% in
3 — 4 hours. Efficiency concentrations of N. in blood make 2 — 8 mkg/ml. At concentration more than 8 mkg! ml arise toxic effects. In N.'s organism turns in atsetilnovokainamid, and then in n-aminobenzoic to - that. During 8 — 12 hours to 81 — 90% of the entered dose of drug it is removed with urine and apprx. 6% — with a stake.
H. apply at treatment of ventrikulyarny and supraventricular arrhythmias. Drug is more effective at paroxysms of ventricular tachycardia and premature ventricular contraction, and also at paroxysms of blinking and an atrial flutter, than at paroxysms of supraventricular tachycardia and premature ventricular contraction. At a resistant ciliary arrhythmia and rare ekstrayenstola of N. it is inefficient. N use also preventively for the prevention of arrhythmias (e.g., at heart operations and the main vessels, after a countershock, etc.).
N appoint intravenously, intramusculary and inside. For stopping of a Bouveret's disease enter intravenously within 5 — 10 min. (under control of an ECG and the ABP) on 2 — 5 — 10 ml of 10% of solution H. into 5% solution of glucose or isotonic solution of sodium chloride. At recovery of a sinoatrial rate administration of drug is finished. In case of decrease in the ABP by 15 mm of mercury. and more introduction of N. should be stopped temporarily. Repeated intravenous administration of drug is possible not earlier than in 2 — 3 hours provided that on an ECG there are no signs of disturbance of conductivity of a myocardium. Inside N. is appointed on 0,5 — 1 g every 3 — 4 hour. Duration of treatment depends on efficiency and portability of drug. In the absence of effect during 48 — 72 hours of an initiation of treatment in a total dose to 6 — 8 g further administration of drug is inexpedient. The highest doses for adults: inside — one-time 1 g, daily 4 g; intramusculary and in a vein (kapelno) — one-time 1 g (10 ml of 10% of solution), daily 3 g (30 ml of 10% of solution).
Side effect of N. is shown by lack of appetite, nausea, vomiting, diarrhea, visual and auditory hallucinations are sometimes noted. At intravenous administration of N. can cause hypotension. Long administration of drug occasionally, hl. obr. at elderly people, leads to development of a syndrome, similar lupoid (skin rashes, polyserosites, a proteinuria); at the same time in blood find LE cells. With drug withdrawal the specified phenomena disappear.
At overdose there can be dangerous complications: atrioventricular blocks of various degree (up to total cross block with Adams-Stokes's attacks), polytopic ventricular extrasystoles, ventricular fibrillation, an asystolia. In case of emergence heart blocks (see) carry out temporary endocardial stimulation it, and at ventricular tachycardia resort to countershock (see). At sharp kollaptoidny reactions to N. stop administration of drug and appoint phenylephine hydrochloride (see) or noradrenaline (see)
N. it is contraindicated at hypersensitivity to it or to novocaine. It is not necessary to apply N. at disturbance of atrioventricular conductivity, the expressed heart failure, a renal failure, and also in the acute period of the myocardial infarction complicated by ventrikulyarny tachycardia or polytopic ventricular premature ventricular contraction. In the latter case appointment is reasonable xycain (see).
Forms of release: tablets on 0,25 g, bottles on 10 ml of 10% of solution, ampoules but 5 ml of 10% of solution. Store in the place protected from light, tablets — in tubes of orange glass.
See also Antiarrhythmic means .
Bibliography: Vinogradov A. V. About treatment of some disturbances of a cordial rhythm novokainamidy, Rubbed. arkh., t. 29, No. 12, page 20, 1957; Clinical pharmacology, under the editorship of V. V. Zakusov, M., 1978; Pa on and to G. and Poe sand E. tesk. Modern medicamentous therapy, the lane from Romanians., page 305, M., 1976; Chazov E. I. and Bogolyubov V. M. Disturbances of a heart rhythm, page 76, M., 1972; Arnsdo'rf M. F. E1e-ctrophysiologic properties of antidysrhyth-mic drugs as a rational basis for therapy, Med. Clin. N. Amer., v. 60, p. 213, 1976; D r e y f u s s J. o. Metabolism of procainamide in rhesus monkey and man, Clin. Pharmacol. Ther., v. 13, p. 366, 1972; Weily H. S. a. Gen ton E. Pharmacokinetics of procainamide, Arch, intern. Med., v. 130, p. 366, 1972.
D. D. Nechayev, V. V. Churyukanov.