Pharmacological action Norpace:
Norpace Class Ia antiarrhythmic drug, blocker “fast” Na +-channels. Has membrane-stabilizing, antiarrhythmic, hypotensive and m-anticholinergic action. With normally functioning sinus node causes the acceleration of sinus rhythm by M-anticholinergic effect. In patients with SSS has a depressing effect on the node, which dominates vagolytic effect. Lengthens the effective refractory period of atria. Facilitates in AV node effective refractory period of AV node is not changed. In patients with impaired AV conduction or bifastsikulyarnoy blockade may develop AV block II-III century. Increases the effective refractory period and duration of action potential in the ventricles. Inhibits impulse conduction in additional ways. Increases PR, without affecting heart rate and blood pressure. At iv administration causes a narrowing of the coronary vessels and increases myocardial oxygen demand.
Indications Norpace:
Treatment and prevention: supraventricular and ventricular premature beats (including the ineffectiveness of lidocaine), paroxysmal arrhythmia (supraventricular tachycardia, nodal tachycardia, atrial and / or atrial flutter, nodal reciprocating tachycardia syndrome WPW, ventricular paroxysmal tachycardia); maintenance of sinus rhythm after drug or electrical cardioversion, the restoration of sinus rhythm (after open-heart surgery in the blink or atrial flutter), prevention of arrhythmias during heart catheterization; HCM (in combination with atrial fibrillation).
Contra Norpace:
Hypersensitivity, CHF IIb-III century., Angle-closure glaucoma, hypotension, prostatic hyperplasia, elongation of the interval QT, AV block II-III century., Cardiogenic shock, SSS, and hepatic or renal nedostatochnost.C caution. Previous therapy drugs that cause bradycardia, AV block, pregnancy, lactation.
Side effects of Norpace:
Paresis of accommodation, dry mouth, nausea, vomiting, constipation and acute urinary retention, headache, dizziness, confusion, insomnia, depression, decreased blood pressure, intrahepatic cholestasis, myasthenia gravis, development or worsening heart failure, AV block I Art., Toning myometrium, peripheral neuropathy, eczema, photosensitivity, and allergic reactions. With prolonged use – agranulocytosis, hypoglycaemia, decrease potentsii.Peredozirovka. Symptoms: apnea, unconsciousness, heart failure, decreased blood pressure, AV block, bradycardia, arrhythmogenic effect.
Administration and Dosage Norpace:
Inside. “Loading dose – 300 mg. After receiving the “loading dose requires blood pressure control. Maintenance dose – 100-200 mg 4 times a day. It is not recommended to start treatment with long-acting forms. Prolonged forms – 300 mg 2 times a day. Patients with severe refractory ventricular tachyarrhythmias – up to 1600 mg / day. In the process of selection of an individual dose of the maintenance dose is gradually reduced to the minimum effective. Patients with atrial flutter or fibrillation before the appointment is held digitalization. In the transition from quinidine or procainamide to disopyramide loading dose is not indicated. In the transition from traditional forms to the prolonged first dose shall be appointed within 6 hours after taking the usual form. Children under 1 year of life – at 10-30 mg / kg / day, 1-4 years – 10-20 mg / kg / day, 4-12 years – 10-15 mg / kg / day, 12-18 years – 6 -15 mg / kg / day. For titration of the child must be hospitalized. In patients weighing less than 50 kg or CHF “loading dose of 200 mg, maintenance – 100 mg with further correction depending on the efficacy and tolerability. When CRF is recommended to adhere to the next interval between administration of maintenance doses: CC 30-40 ml / min – every 8 h, 15-30 mL / min – 12 h, less than 15 ml / min – 24 hours
Special instructions:
Should not be used for asymptomatic ventricular arrhythmia. Criteria for monitoring the effectiveness of treatment: antiarrhythmic efficacy in ventricular tachyarrhythmias assessed by intracardiac electrophysiological studies. When ventricular arrhythmia general rule is to reduce the number of extrasystoles by 70% from baseline (based on daily monitoring by Holter). Choosing the right dose should enhance the QRS complex or lengthen the QT interval by 25% from baseline. Methods and control regime of side effects: periodic determination of glucose, K +, activity of liver enzymes, control of blood pressure and electrocardiogram (an extension of the QRS complex or prolongation QT). With the development of AV block I Art. dose is reduced. If the blockage persists or progresses, the drug overturned. Requires control of intraocular pressure.
Interaction:
Narcotic analgesics, activated charcoal reduces the extent of absorption of the drug. Rifampicin accelerates the metabolism in the liver. Beta-blockers, verapamil, digoxin increase the risk of bradycardia and hypotension. Diuretics, tricyclic antidepressants, anti-arrhythmic drugs class III increase the risk of ventricular tachycardia of “pirouette”.
