CORDARONE

CORDARONE

GENERIC NAME:

Amiodarone HCI

Indication:

Ø  Atrial rhythm disorder  ( conversion of fibrillation of flutter, and maintaince of sinus rhythm following conversion)

Ø  Nodal rhythm disorder

Ø  Ventricular rhythm disorders ( life – threatening ventricular premature contractions , ventricular tachycardia salves, prevention of ventricular tachycardia attacks or ventricular fibrillation episodes).

Contraindication:

Ø  Sinus bradycardia & SA heart block.

Ø   Severe conduction disturbances (high grade AV block, bifascicular or trifascicular block) or sinus node disease, except when used in conjunction w/ a pacemaker.

Ø  Hyperthyroidism due to its possible exacerbation by amiodarone

Ø   Hypersensitivity to iodine or to amiodarone

Ø  The last 6 months of pregnancy

Ø  Use w/ drugs which may induce torsades de pointes

·         Class la antiarrhythmics ( quinidine,hydroquinidine,disopyramide,etc)

·         Class 111 antiarrthythmics ( sotatolo, dofetilide,ibutilide,etc)

·         Sultoppride

·         Other medication such as beprilid, cisapride, diphemenil,erythromycin iv,mizolastine,sparfloxacin,etc.

Dosage

Ø  Tablet Initially 200 mg tds for 1 wk, then 200 mg bd for another wk. Maintenance: 100-400 mg daily.

Ø   Amp IV infusion: Loading dose: 5 mg/kg in 250 mL dextrose 5% or normal saline 0.9% over a period of 20 min-2 hr. Further doses may be given up to a max of 1,200 mg (approx 15 mg/kg) in up to 500 mL of dextrose 5% or normal saline 0.9%  per 24 hr.

Ø   IV inj: In emergencies: 150-300 mg in 10-20 mL dextrose 5% over at least 3 min.

Dilution:

Ø   LOADING DOSE:

·         2 amp = 300mg dilute in 50 cc syringe of dextrose 5% or normal saline 0.9% over 30 minute or  1 hours

Ø  MAINTENANCE DOSE:

·         4 amp = 600mg dilute in 50 cc syringe of dextrose 5% or normal saline 0.9%

Over  24 hours.

(Drug dose depend on doctor order)

Special Precaution:

      Hypotension; decompensated cardiomyopathy; severe heart failure; elderly; renal impairment.

      Excessive dosage may lead to severe bradycardia & conduction disturbances (esp in elderly or during digitalis therapy)

      .Avoid concomitant use w/ β-blockers, heart rate-lowering Ca-channel blockers (verapamil, diltiazem), stimulant laxatives which may cause hypokalaemia.

      Monitor patient when used w/ flecainide. Amp Too rapid administration or overdosage may precipitate circulatory collapse.

Adverse Drug Reaction:

      Bradycardia

      hypothyroidism

      hyperthyroidism (sometimes fatal)

      reversible corneal microdeposits, benign GI disorders, moderate increase in serum transaminases

      acute liver disorders w/ high serum transaminases &/or jaundice, including hepatic failure (sometimes fatal)

       extrapyramidal tremor, nightmares, sleep disorders

      pulmonary toxicity (hypersensitivity pneumonitis, alveolar/interstitial pneumonitis or fibrosis, pleuritis, sometimes fatal bronchiolitis obliterans organising pneumonia, sometimes fatal)

      photosensitivity, slate grey or bluish pigmentations of light-exposed skin, particularly in the face.

Amp Inj site reactions:

      moderate & transient decrease in BP.

       haemolytic or aplastic anaemia, thrombocytopenia, onset or worsening of arrhythmia, conduction disturbances, marked bradycardia or sinus arrest in patients w/ sinus node dysfunction &/or elderly patients

       optic neuropathy/neuritis which may progress to blindness, chronic liver disease, peripheral sensorimotor neuropathy &/or myopathy (usually reversible)

       bronchospasm in patients w/ severe resp failure & esp in asthmatic patients, alopecia, erythema during the course of radiotherapy, rashes (including exfoliative dermatitis), vasculitis.

      Anaphylactic shock.

Drug Interaction:

      Warfarin, digoxin, phenytoin, drugs metabolised by cytochrome P-450 3A4 (eg cyclosporin, statins, lidocaine, tacrolimus, sildenafil, fentanyl, midazolam, ergotamine), flecainide

·         Increase plasma conc of drugs metabolised by CYP 1A2, CYP 2C19 & CYP 2D6. Use w/ the following drugs which prolong the QT interval is contraindicated

      Class Ia antiarrhythmics (eg quinidine, procainamide, disopyramide); class III antiarrhythmics (eg sotalol, bretylium); IV erythromycin, co-trimoxazole or pentamidine inj; some antipsychotics (eg chlorpromazine, thioridazine, fluphenazine, pimozide, haloperidol, amisulpride & sertindole); lithium & tricyclic antidepressants (eg doxepin, maprotiline, amitriptyline); certain antihistamines (eg terfenadine, astemizole, mizolastine); antimalarials (eg mefloquine, chloroquine, halofantrine).

·         Combined therapy w/ the following is not recommended: β-blockers, heart rate-lowering Ca-channel blockers (verapamil, diltiazem), stimulant laxatives which may cause hypokalaemia.

·         Caution when used w/ drugs which may cause hypokalaemia &/or hypomagnesaemia (eg diuretics, systemic corticosteroids, tetracosactide, IV amphotericin) & in patients undergoing general anesth or high dose O₂ therapy.