Rythma

Life-threatening ventricular & supraventricular arrhythmias refractory to other antiarrhythmics. Inj: Severe rhythm disorders, especially supraventricular rhythm disorders, tachycardia associated w/ Wolff-Parkinson-White syndrome, ventricular rhythm disorder (recurrent ventricular fibrillation & recurrent hemodynamically unstable ventricular tachycardia in patients refractory to other therapy). Patients w/ rhythm disorders where rapid response is required or where PO is not possible.

Tab Saturation dose: 600 mg/day for 8-10 days, may be increased up to 1,200 mg/day. Maintenance dose: Reduce to 200 mg for 5 days/wk. Long-term therapy: 200-600 mg/day. Childn Adjust dose according to BSA or body wt. Inj Loading infusion: Initial rapid infusion phase: 150 mg (3 mL) over 10 min. Rate: 15 mg/min; Slow infusion phase: 360 mg over 6 hr. Rate: 1 mg/min. Maintenance infusion: 540 mg over 18 hr. Rate: 0.5 mg/min. After the 1st 24 hr, continue maintenance infusion rate of 0.5 mg/min (ie, 720 mg over 24 hr). In event of breakthrough episodes of ventricular fibrillation or hemodynamically unstable ventricular tachycardia, supplemental infusions of 150 mg over 10 min at rate of 15 mg/min may be given.

May be taken with or without food: Tab: Should be taken unchewed during or after meals together w/ sufficient liqd.

Hypersensitivity to amiodarone or iodine. Sinus bradycardia & SA heart block; sick sinus syndrome or sinus node disease (except when used w/ pacemaker); AV heart blocks, bi- or tri-fascicular conduction disorders when not used w/ pacemaker. Concomitant use w/ drugs which may induce torsades de pointes. Pregnancy & lactation. Tab: Preexisting QT prolongation; hypokalemia. Concomitant use w/ MAOI, >20 mg simvastatin daily. Inj: Evidence or history of thyroid dysfunction; circulatory collapse, severe arterial hypotension.

Risk of severe inflammatory pneumopathy (alveolar or interstitial, hypersensitivity pneumonitis). Increased risk of torsades de pointes in excessive QT prolongation. Possibility of syndrome of inappropriate secretion of antidiuretic hormone (SIADH) in patients experiencing asthenia during amiodarone therapy. Avoid exposure to sun or use protective measures during therapy. Examine thyroid function prior to onset of treatment, repeat at regular intervals during therapy & up to 1 yr after w/drawing from therapy, & examine patients for clinical symptoms of hyperthyroidism or hypothyroidism. Perform thoracic roentgenography & pulmonary function test prior to onset of treatment, repeat at intervals of approx 3-6 mth in further therapeutic course, & carry out if dyspnea occurs. Monitor liver values at regular intervals particularly at high dosage. Measure Na levels & osmolality in serum. May affect ability to drive or operate machinery. Childn. Elderly. Tab: Perform regular ophth exam including funduscopy & slit-lamp exam during treatment. Not to be taken by patients w/ galactose intolerance, Lapp lactase deficiency or glucose-galactose malabsorption. Increased risk of myopathy/rhabdomyolysis w/ simvastatin. Inj: Discontinue use in case of onset of 2nd & 3rd degree AV block, SA block, or bifascicular block. Not to be administered via peripheral vein. Intended for use only in patients w/ the indicated life-threatening arrhythmias. Dyspnea or non-productive cough may be related to pulmonary toxicity. May induce thyroid disorders particularly in patients w/ personal or family history of thyroid disorders. Contains iodine which may interfere w/ radioiodine uptake. Initially treat hypotension occurring w/ therapy by slowing infusion & possibly additional standard therapy including vasopressor drugs, +ve inotropic agents, & vol expansion. Perform ECG, usTSH assay & serum K measurement prior to initiation of treatment. Measure serum usTSH level when regular dysfunction is suspected.

Tab: Microdeposits at anterior surface of the cornea, optic neuritis; photosensitization w/ increased tendency to sunburns, pseudocyanosis (in long-term treatment), erythematous development on RT, erythema nodosum; thyroid dysfunctions (hyperthyroidism or hypothyroidism); atypical pneumonia, alveolar or interstitial pneumonitis or fibroses, pleuritis, bronchiolitis obliterans w/ pneumonia/BOOP, shock lung acute resp distress syndrome (mostly after surgery); nausea & vomiting, abdominal pain, sensation of repletion, constipation & anorexia, isolated increases in serum transaminases; sinus bradycardia, sinus node arrest, asystole, torsades de pointes & ventricular fibrillation/flutter; fatigue, headache, dyssomnia, nightmares, vertigo, diminished libido, myasthenia, tremor, impaired coordination, paresthesia, peripheral neuropathy or ataxia. Inj: Fever; bradycardia, CHF, heart arrest, hypotension (sometimes fatal), ventricular tachycardia, atrial & ventricular fibrillation, nodal arrhythmia, prolonged QT interval, shock, sinus bradycardia & arrest, angioedema; abnormal LFTs & kidney function, nausea, diarrhea, increased ALT & AST, vomiting, hepatitis, cirrhosis, pancreatitis; lung edema, resp disorder, bronchospasm, possibly fatal resp disorders (including distress, failure, arrest, & ARDS), bronchiolitis obliterans organizing pneumonia (possibly fatal), dyspnea, cough, hemoptysis, wheezing, hypoxia, pulmonary infiltrates &/or mass, pleuritis; nausea, vomiting, constipation, abdominal pain, abnormal salivation, anorexia, epigastric burning or fullness, & pancreatitis; SJS, TEN (sometimes fatal), erythema multiforme, exfoliative dermatitis, skin cancer, pruritus, inj site reactions (pain, erythema, edema, pigment changes, venous thrombosis, phlebitis, thrombophlebitis, cellulitis, necrosis & skin sloughing); hallucination, confusional state, disorientation, delirium; thrombocytopenia, hemolytic & aplastic anemia, pancytopenia, neutropenia, agranulocytosis; thyroid nodules/cancer; anaphylactic/anaphylactoid reaction (including shock), renal impairment & insufficiency, acute renal failure, pseudotumor cerebri, SIADH, vasculitis, granuloma, myopathy, muscle weakness, rhabdomyolysis, epididymitis & impotence.

Myopathy/rhabdomyolysis w/ HMG-CoA reductase inhibitors. Increased serum conc of digoxin. Tab: May lead to automatism disturbances (excessive bradycardia) & disturbances in AV conduction due to synergistic effect w/ cardiac glycosides. Intensified anticoagulant effect & hence increased bleeding risk of vit K antagonists eg, phenprocoumon & warfarin. May increase serum conc of phenytoin & precipitate symptoms of phenytoin overdose (eg, visual disturbances, tremor, vertigo). Increased serum conc & decreased clearance of ciclosporin. Increased plasma levels of other antiarrhythmics eg, quinidine, procainamide, flecainide. Risk of excessive QT prolongation combined w/ increased risk of ventricular arrhythmias including torsades de pointes w/ antiarrhythmics class I (especially quinidine-like substances) & other antiarrhythmics class III (eg, sotalol), other medicinal products prolonging QT time (eg, vincamine, sulpiride, pentamidine IV & erythromycin IV). Increased risk of occurrence of hypokalemically-induced arrhythmias (including torsades de pointes) w/ K-depleting diuretics (eg, hydrochlorothiazide, furosemide), laxatives, systemic corticosteroids, tetracosactide or amphotericin B IV. May lead to excessive bradycardia, higher grade AV conduction disturbances & to additive cardiodepressive effects w/ Ca antagonists of verapamil & diltiazem type or β-adrenergic blockers. Rare cases of atropine-resistant bradycardia, fall in BP, conduction disturbances & reduced cardiac output w/ general anesth. Inj: May result in unexpectedly high plasma conc of other drugs metabolized by CYP2D6, CYP1A2, CYP2C9, CYP3A4 & CYP2C8 isoenzymes. Concomitant use w/ HIV PIs; other antiarrhythmic agents eg, disopyramide, mexiletine, propafenone, flecainide, procainamide, quinidine, bepridil, sotalol, diphemanil. QT interval prolongation & torsades de pointes w/ loratadine; trazodone. Increased serum levels w/ cimetidine. Persistently elevated plasma conc resulting in elevated creatinine w/ cyclosporine. Possible potentiation of bradycardia, sinus arrest, & AV block w/ β-receptor blockers (eg, propranolol) or Ca channel antagonists (eg, verapamil, diltiazem). Potentiated anticoagulant response of warfarin; fluindione. Potential interaction resulting in ineffective inhibition of platelet aggregation w/ clopidogrel. Decreased serum conc w/ rifampin. May cause hypotension, bradycardia, & decreased cardiac output w/ fentanyl. Sinus bradycardia & seizure w/ lidocaine. Impaired metabolism of dextromethorphan; phenytoin & MTX (in chronic use >2 wk). Potentially reduced levels w/ St. John's wort. Increased AUC & C_max w/ grapefruit juice. Potentially serious cardiac arrhythmias including torsades de pointes w/ other drugs prolonging QT_c interval eg, cisapride, halofantrine, pimozide, disopyramide, fluoroquinolones, macrolides, azole antifungals. Increased enterohepatic elimination & potentially reduced serum levels & t_1/2 w/ cholestyramine. May increase risk of potentially lethal torsades de pointes w/ non-antiarrhythmic agents including vincamine, sultopride, sparfloxacin, erythromycin IV & pentamidine. May result in elevated risk of ventricular arrhythmias, including ventricular tachycardia & torsades de pointes w/ agents producing hypokalemia &/or hypomagnesemia eg, K-wasting diuretics, amphotericin B, cation exchange resins, stimulant laxatives. May decrease serum conc of amiodarone w/ rifamycin.

Cardiac Drugs

C01BD01 - amiodarone ; Belongs to class III antiarrhythmics.

Rx