Rythma Dosage/Direction for Use

Tablet: In patients with ventricular arrhythmias, adjustment to the antiarrhythmic requires careful cardiologic monitoring and may only be carried out if cardiologic emergency equipment is available and monitoring control possible. During treatment, check-tests should be made at regular intervals [eg, standard electrocardiogram (ECG) at intervals of 1 month or long-term ECG at intervals of 3 months and possibly exercise ECG].
Therapy should be reviewed if individual parameters deteriorate eg, prolongation of QRS time or QT time by >25% or PQ time by >50% or QT prolongation to >500 ms or increase in the number or severity of arrhythmias.
As saturation dose, 600 mg amiodarone HCl is given for 8-10 days (equivalent to 3 tablets of amiodarone 200 mg) per day. In some cases, dosages of up to 1200 mg amiodarone HCl (equivalent to 6 tablets of amiodarone HCl 200 mg) may become necessary per day. Afterwards, reduction to a maintenance dose, usually 200 mg amiodarone HCl (equivalent to 1 tablet of amiodarone HCl 200 mg) for 5 days per week may be initiated.
In some cases, higher dosages of 200-600 mg amiodarone HCl (equivalent to 1-3 tablets of amiodarone HCl 200 mg) per day are required during long-term therapy.
For the treatment of children, the dosage should be adjusted to the body surface area or to the body weight.
Special Note: As most of adverse reactions are dose-dependent, the lowest effective maintenance dose should be administered.
Injection: Amiodarone should only be used in a special care unit with continuous monitoring of blood pressure and ECG. Rythma should be administered only by physicians who are experienced in the treatment of fatal arrhythmias and are totally familiar with the risks and benefits of amiodarone therapy.
Carefully adjust dosage according to individual requirements and response, patient tolerance, and the patient's general condition and cardiovascular status.
The recommended IV amiodarone HCl starting dose over the first 24 hrs is approximately 1000 mg, administered by the infusion regimen as follows. (See Table 1.)

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After the first 24 hrs, continue a maintenance infusion rate of 0.5 mg/min (ie, 720 mg over 24 hrs).
In the event of breakthrough episodes of ventricular fibrillation or hemodynamically unstable ventricular tachycardia, supplemental amiodarone HCl infusions of 150 mg administered over 10 min at a rate of 15 mg/min may be given.
Clinical trials on amiodarone HCl IV reported that a maintenance infusion of up to 0.5 mg/min can be administered with caution for 2-3 weeks, regardless of patient's age, renal function or left ventricular function. There has been limited experience on the use of amiodarone HCl IV for >3 weeks.
Administration: Tablet: It should be taken unchewed during or after meals together with sufficient liquid. The attending physician decides on the duration of administration.
Injection: Amiodarone IV should never be administered via a peripheral vein. It should always be administered exclusively as an infusion through a central venous catheter. Injection via the peripheral venous route, even at a very slow rate can cause local effects eg, superficial phlebitis, and may aggravate hypotension, heart failure, myocardiopathy or severe respiratory insufficiency.
For infusions lasting >1 hr, the concentration should not exceed 2 mg/mL unless administered via a central venous catheter. Infusions lasting >2 hrs must be administered in polyolefin or glass bottles containing D₅W. Use of evacuated glass containers for admixing amiodarone is not recommended as incompatibility with a buffer in the container may cause precipitation.
Amiodarone injection should only be administered using a volumetric infusion pump. An in-line filter should be used during administration.
Polyvinyl chloride (PVC) tubing should be used during IV administration. The recommended dosing regimens have taken into account the amount of amiodarone adsorbed to PVC tubing.
Admixture Incompatibility: Amiodarone IV in D₅W, in a concentration of 4 mg/mL, is incompatible and forms a precipitate with the following drugs: Aminophylline, cefamandole, cefazolin, mezlocillin. A concentration of 3 mg/mL amiodarone IV in D₅W forms a precipitate with sodium bicarbonate. Amiodarone is likewise incompatible with heparin.
Conversion from IV to Oral Dosage: Use amiodarone IV for acute treatment until the patient's ventricular arrhythmias are stabilized. Patients whose arrhythmias have been successfully controlled with amiodarone IV may be transferred to oral therapy. The optimal dose for changing from IV to oral administration will depend on the IV dose already administered, as well as the bioavailability of oral amiodarone. When changing to oral therapy, clinical monitoring is recommended, particularly for elderly patients.
Table 2 as follows, provides suggested doses of oral amiodarone to be initiated after varying durations of IV administration. These recommendations are made on the basis of a comparable total body amount of amiodarone delivered by the IV and oral routes, based on 50% bioavailability of oral amiodarone. (See Table 2.)

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Stability: Amiodarone adsorbs to PVC tubing and the clinical trial dose administration schedule was designed to account for this adsorption. Clinical trials were conducted using PVC tubing; therefore its use is recommended.
Amiodarone has been found to leach out plasticizers, including di-ethylhexyl phthalate (DEHP) from IV tubing (including PVC tubing). The degree of leaching increases when infusing amiodarone IV at higher concentrations and lower flow rates than recommended.