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Amiodarone Uses, Dosage, Side Effects & Warnings | DrugsAtlas

Authoritative Clinical Reference

Potassium Channel Blockers

Drug Name: Amiodarone

Therapeutic Class:

Antiarrhythmic

Subclass:

Class III Antiarrhythmic (Potassium Channel Blocker)

Speciality

Cardiology

Schedule (India):

Schedule H

Routes

Oral, Intravenous

Formulations

Tablets: 100 mg, 200 mg
Injection: 150 mg/3 mL (50 mg/mL) ampoule

Adult indications

INDICATIONS + DOSING — FOR CLINICIAN USE ONLY

Primary Indications (Approved / Standard in India)

1. Ventricular Tachyarrhythmias (VT/VF, particularly in structural heart disease)

A. Intravenous Route (Acute/Emergency Setting)

Parameter	Recommendation
Starting dose (Loading)	150 mg IV over 10 minutes (dilute in 100 mL 5% dextrose)
Titration	1 mg/min for 6 hours → then 0.5 mg/min for 18 hours
Usual maintenance dose	Convert to oral therapy after stabilization
Maximum dose	2.2 g IV in first 24 hours

B. Oral Route (Maintenance/Chronic Therapy)

Parameter	Recommendation
Starting dose (Loading)	800–1200 mg/day in 2–3 divided doses for 1–2 weeks
Titration	Reduce by 200 mg every 5–7 days based on response
Usual maintenance dose	200–400 mg once daily
Maximum dose	600 mg/day (short-term); 400 mg/day preferred for chronic use

Clinical Notes:

Adjust dosing based on rhythm control response and safety parameters
Long half-life (40–55 days) necessitates loading phase
ECG monitoring mandatory during IV administration

2. Supraventricular Tachyarrhythmias (Atrial Fibrillation — rhythm control in structural heart disease or LV dysfunction)

Parameter	Recommendation
Starting dose (Loading)	600–800 mg/day in divided doses for 1 week
Titration	Reduce by 200 mg every 5–7 days
Usual maintenance dose	100–400 mg once daily
Maximum dose	400 mg/day for long-term use

Clinical Notes:

Initiate only when cardioversion is planned or in recurrent AF
Preferred in patients with heart failure or structural heart disease where other antiarrhythmics are contraindicated
Not first-line for lone AF

3. Prevention of Recurrent VT/VF in ICD Patients (Adjunct to Device Therapy)

Parameter	Recommendation
Starting dose	400 mg/day in divided doses for 1–2 weeks
Titration	Reduce based on ICD interrogation and arrhythmia burden
Usual maintenance dose	100–200 mg once daily
Maximum dose	400 mg/day

Clinical Notes:

Used to reduce frequency of appropriate ICD shocks
Lower maintenance doses preferred to minimize toxicity

Secondary Indications — Adults (Off-label, if any)

Indication	Dose	Duration	Supervision	Label Status	Evidence Basis
Acute rate control in atrial fibrillation (when beta-blockers/CCBs contraindicated)	150 mg IV over 10–15 min, then 1 mg/min × 6 hours, then 0.5 mg/min	Until rate controlled	Specialist/ICU only	OFF-LABEL	RCTs in acute AF; not first-line per ICMR/API guidelines

Paediatric indications

PAEDIATRIC DOSING (Specialist Only)

Primary Indications

Supraventricular Tachycardia (SVT) or Ventricular Tachycardia

A. Intravenous Route (ICU/Specialist Setting Only)

Parameter	Recommendation
Starting dose (Loading)	5 mg/kg IV over 20–60 minutes (dilute in D5W)
Titration	May repeat loading dose; total up to 15 mg/kg/day
Usual maintenance dose	5–15 mcg/kg/min continuous infusion
Maximum dose	15 mg/kg/day OR 1.5 mg/kg/day maintenance

B. Oral Route (After Stabilization)

Parameter	Recommendation
Starting dose (Loading)	10–15 mg/kg/day in 2–3 divided doses for 5–10 days
Titration	Reduce gradually based on arrhythmia control
Usual maintenance dose	5–10 mg/kg/day in 1–2 divided doses
Maximum dose	200–400 mg/day (weight and age dependent)

Age Restrictions:

NOT recommended below 1 year of age except under paediatric cardiology supervision in tertiary care

Safety Monitoring:

Baseline: ECG (QTc), LFTs, TFTs, chest X-ray
Ophthalmology examination if use exceeds 6 months
Monitor growth parameters

Secondary Indications — Paediatric Doses (Off-label, if any)

Indication	Dose	Duration	Supervision	Label Status	Evidence Basis
Fetal tachyarrhythmia (via maternal administration)	Individualized maternal dosing	Until delivery/resolution	Maternal-fetal medicine + Paediatric cardiology	OFF-LABEL	Case series from Indian referral centres

Renal Adjustments

Renal Function	Recommendation
All stages of renal impairment	No dose adjustment required
Haemodialysis	Not dialyzable (large volume of distribution); no supplemental dose needed
Peritoneal dialysis	No dose adjustment required

Hepatic adjustment

Severity	Recommendation
Mild impairment	Start at lowest effective dose (100–200 mg/day); monitor LFTs every 2–4 weeks initially
Moderate impairment	Use with caution; consider 50% dose reduction; frequent LFT monitoring
Severe impairment	Avoid unless no alternative; specialist supervision mandatory

Contraindications

Sinus node dysfunction (unless permanent pacemaker in situ)
Second-degree or third-degree AV block (unless permanent pacemaker in situ)
Severe sinus bradycardia (<50 bpm, symptomatic)
Known hypersensitivity to amiodarone or iodine
Severe thyroid dysfunction (overt hyperthyroidism or hypothyroidism)
Pregnancy (except for life-threatening arrhythmias — see Pregnancy section)
Concurrent use of drugs causing torsades de pointes with no monitoring capability

Cautions

Pre-existing pulmonary disease — increased risk of amiodarone-induced pulmonary toxicity
Thyroid disorders — can cause both hypothyroidism and hyperthyroidism
Hepatic dysfunction — hepatotoxicity risk even with normal baseline LFTs
Baseline QT prolongation — risk of torsades de pointes
Electrolyte abnormalities — correct hypokalaemia and hypomagnesaemia before initiation
Photosensitivity — advise sun protection measures
Corneal microdeposits — usually asymptomatic but may cause visual halos
Elderly patients — increased sensitivity to all adverse effects
Concurrent use of other negative chronotropes

Pregnancy

Parameter	Recommendation
Risk category/Safety statement	Avoid — crosses placenta; associated with fetal thyroid dysfunction, goitre, growth restriction, and neurodevelopmental concerns
Preferred alternatives	Beta-blockers (metoprolol, propranolol) or digoxin depending on arrhythmia type
When it may be used	Life-threatening arrhythmias refractory to safer alternatives; specialist decision only
Monitoring	Maternal: ECG, LFTs, TFTs; Fetal: serial ultrasound for growth, thyroid size, cardiac function

Lactation

Parameter	Recommendation
Compatibility	Not recommended — significant excretion into breast milk
Preferred alternatives	Propranolol, sotalol (if appropriate for indication)
Expected drug levels in milk	Moderate to high; infant receives significant iodine load
Infant monitoring	If unavoidable: monitor infant TFTs, weight gain, feeding patterns, cardiac status

Elderly

Parameter	Recommendation
Starting dose	100–200 mg/day oral; lower IV loading doses may be considered
Titration	Slower titration recommended; assess response over weeks
Extra risks	Enhanced susceptibility to bradycardia, hypotension, thyroid dysfunction, pulmonary toxicity, hepatotoxicity; falls risk with hypotension; polypharmacy interactions common

Major drug interactions

Interacting Drug	Effect/Mechanism	Recommendation
Digoxin	Increased digoxin levels (inhibits P-glycoprotein)	Reduce digoxin dose by 50%; monitor levels
Warfarin	Increased INR (CYP2C9 inhibition)	Reduce warfarin by 30–50%; monitor INR frequently
Simvastatin	Increased myopathy/rhabdomyolysis risk (CYP3A4 inhibition)	Limit simvastatin to ≤20 mg/day; consider alternative statin
QT-prolonging drugs (fluoroquinolones, macrolides, azole antifungals, antipsychotics, ondansetron)	Additive QT prolongation; risk of torsades de pointes	Avoid combination or ensure ECG monitoring
Strong CYP3A4 inhibitors (ketoconazole, itraconazole, ritonavir)	Increased amiodarone levels and toxicity	Avoid or reduce amiodarone dose
Grapefruit juice	Increased amiodarone absorption and levels	Avoid concurrent intake

Moderate drug interactions

Interacting Drug	Effect/Mechanism	Recommendation
Beta-blockers	Additive bradycardia and AV block	Use with caution; monitor heart rate and ECG
Diltiazem, Verapamil	Additive negative chronotropic and dromotropic effects	Monitor for bradycardia; avoid high doses
Phenytoin	Increased phenytoin levels (CYP2C9 inhibition)	Monitor phenytoin levels; adjust dose if needed
Rifampicin	Decreased amiodarone efficacy (CYP3A4 induction)	Monitor for loss of arrhythmia control
Ciclosporin	Increased ciclosporin levels	Monitor ciclosporin levels
Aluminium/magnesium antacids	May reduce oral amiodarone absorption	Separate administration by 2 hours
Fentanyl	Enhanced cardiovascular depression	Use with caution in perioperative settings

Common Adverse effects

Corneal microdeposits (>90% with long-term use; usually asymptomatic, may cause visual halos)
Photosensitivity and blue-grey skin discolouration
Bradycardia
Nausea, anorexia, constipation
Hypothyroidism (more common) or hyperthyroidism
Elevated hepatic transaminases (usually asymptomatic)
Tremor, ataxia, peripheral neuropathy
Sleep disturbances

Serious Adverse effects

Adverse Effect	Clinical Action
Pulmonary toxicity (pneumonitis, fibrosis)	Potentially fatal; discontinue immediately; may require corticosteroids
Hepatotoxicity (transaminases >3× ULN or clinical hepatitis)	Discontinue; monitor for recovery
Torsades de pointes	Rare but life-threatening; discontinue; correct electrolytes; may need pacing
Optic neuritis/neuropathy	Can cause permanent vision loss; discontinue immediately
Thyroid storm (amiodarone-induced thyrotoxicosis)	Medical emergency; specialist management required
Severe bradycardia/sinus arrest/complete heart block	May require pacing; discontinue if possible
Stevens-Johnson Syndrome/TEN	Discontinue immediately; supportive care

Monitoring requirements

Timing	Parameters
Baseline (before initiation)	ECG (rhythm, QTc), LFTs, TFTs (TSH, free T4, free T3), chest X-ray, serum potassium and magnesium, pulmonary function tests if respiratory symptoms
After initiation (first 3–6 months)	ECG: after loading and at 1, 3 months; LFTs: monthly for 3 months then 3-monthly; TFTs: at 3 months
Long-term (chronic use)	TFTs and LFTs: every 6 months; ECG: every 6 months; Chest X-ray: annually or with symptoms; Ophthalmology: annually or if visual symptoms; Pulmonary function/HRCT: if new respiratory symptoms

Brands in India

Brand Name	Manufacturer	Formulation
Cordarone	Sanofi	Tablets 200 mg, Injection
Cordarone X	Pfizer	Tablets 200 mg
Amiodon	Samarth	Tablets 100 mg, 200 mg
Duron	Intas	Tablets 200 mg
Eurythmic	Micro Labs	Tablets 100 mg, 200 mg; Injection
Aldarone	Alkem	Tablets 200 mg

Note: Also available as hospital-supply generics

Price range (INR)

Formulation	Approximate Price
Unidentifiedcccc	₹4–10 per tablet
Tablet 200 mg	₹6–15 per tablet
Injection 150 mg/3 mL	₹40–90 per ampoule

Note: Not currently under DPCO/NLEM price control. Prices vary between government and private supply chains.

Clinical pearls

Loading is mandatory: Due to extremely long half-life (40–55 days) and high volume of distribution, adequate loading is essential before maintenance.
Thyroid vigilance: Contains ~37% iodine by weight; inhibits peripheral T4→T3 conversion. Both hypo- and hyperthyroidism can occur — hyperthyroidism is more dangerous and may require thyroidectomy.
Pulmonary toxicity is unpredictable: Not strictly dose-dependent; can occur at any dose. Annual chest X-ray and immediate evaluation for new respiratory symptoms essential.
Drug interactions are extensive: Always review concomitant medications. Reduce digoxin by 50% and warfarin by 30–50% when initiating amiodarone.
Effects persist after stopping: Due to tissue accumulation, adverse effects and drug interactions may persist for weeks to months after discontinuation.
Preferred in structural heart disease: Amiodarone is the antiarrhythmic of choice for VT/VF and AF in patients with heart failure or significant LV dysfunction where other agents are contraindicated.

Version

RxIndia v1.0 — 01 Apr 2025

Reference

- CDSCO approved prescribing information
- Indian Pharmacopoeia / National Formulary of India
- API Textbook of Medicine
- Harrison's Principles of Internal Medicine
- AIIMS Pharmacology Department protocols
- ICMR Guidelines on Atrial Fibrillation and Ventricular Arrhythmia Management
- Cardiological Society of India practice recommendations
- Select RCTs/meta-analyses (for off-label IV rate control indication)

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Clinical Responsibility

This platform is designed strictly for healthcare professionals. Data provided is synthesized from authoritative pharmacological sources and clinical registries. Do not use for consumer medical decisions. Always verify critical dosing and contraindications with official institutional protocols and peer-reviewed journals.

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