Clinical beta

FMBM is currently in clinical beta. Content is for professional review/testing and must not replace local protocols, senior clinical judgment, or official prescribing references.

Drug Monograph

Amiodarone

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USE IF: Ventricular arrhythmias, selected AF rate/rhythm control when alternatives unsuitable, ACLS shock-refractory VF/VT — with BP/rhythm monitoring (IV), baseline + serial thyroid/LFT/pulmonary surveillance (chronic), and interaction review (warfarin, digoxin, BB/CCB, QT drugs).

AVOID IF: Unpaced severe sinus / high-grade AV nodal disease; ignoring prolonged QT / stacked QT agents; chronic therapy without baseline labs and monitoring plan; treating IV and PO dosing as interchangeable.

Amiodarone

Class III antiarrhythmic (multi-channel effects)

AdultICUCardiologyAntiarrhythmicERWardACLS

Indication

VT/VF • AF (selected) • ACLS refractory VF/VT • Structural heart disease contexts where other antiarrhythmics avoided

At a glance

INDICATIONS (CORE USE)

- Ventricular arrhythmias (VT, VF) - Atrial fibrillation (rate/rhythm control when others unsuitable) - ACLS shock-refractory VF/VT (protocol)

ADULT DOSE (STANDARD)

IV (acute/ICU): e.g., 150 mg IV over 10 min (protocol) → infusion per protocol PO (chronic): loading phase (high-dose) → maintenance (lower daily dose) — institution-specific

MAX DOSE

Protocol-dependent — avoid oversimplified universal max; cumulative toxicity dominates long-term

Route

IV / PO

PEDIATRIC DOSE

Specialist / protocol-based only

Do not miss

Must-not-miss safety points

Major warning

- Multi-organ toxicity (thyroid, liver, lung) - Very long half-life → effects persist for weeks–months - QT prolongation (torsades risk lower than other agents but still relevant) - Major drug interactions (warfarin, digoxin, many others) - IV use → hypotension / bradycardia risk - Pulmonary toxicity can be fatal

Indications

Primary

  • Ventricular arrhythmias (VT, VF)
  • Atrial fibrillation (rate/rhythm control when others unsuitable)

Secondary

  • ACLS protocols (shock-refractory VF/VT)

Dosing

STANDARD (ADULT PO)

IV (acute/ICU): bolus e.g., 150 mg IV over 10 min (protocol-based) → continuous infusion per protocol PO (chronic): loading phase (high-dose) → maintenance (lower daily dose)

ADULT DOSE

IV vs PO are NOT directly interchangeable — use pathway-specific dosing tables Chronic oral therapy requires loading due to large volume of distribution Avoid rapid IV bolus outside shock-refractory ACLS / explicit protocol allowances

PEDIATRIC DOSE

Specialist / protocol-based only

MAX DOSE

Protocol-dependent cumulative limits — toxicity, not a single number, caps long-term exposure

Practical Note

- IV: hemodynamic and rhythm monitoring; hypotension / bradycardia common early - PO: consistent daily timing once maintenance reached; expect delayed oral steady state - Half-life measured in weeks — drug interactions and toxicity persist long after last dose mentally - One of few antiarrhythmics often retained in reduced LVEF / structural disease — still not “benign”

Warnings

Clinical warnings

  • Pulmonary toxicity (pneumonitis, fibrosis) — can be fatal
  • Thyroid dysfunction (hypo- or hyperthyroidism)
  • Hepatotoxicity
  • Bradycardia / AV block (especially with BB, verapamil, diltiazem, digoxin)
  • QT prolongation — additive risk with other QT prolongers
  • Photosensitivity / blue-gray skin (long-term)

Contraindications

  • Severe sinus node dysfunction (without pacing)
  • High-grade AV block (without pacing)
  • Known hypersensitivity

Drug interactions

  • Warfarin → ↑ INR / bleeding risk (major — frequent INR checks when co-started or dose-changed)
  • Digoxin → ↑ digoxin levels — reduce digoxin dose and monitor levels/symptoms
  • Beta-blockers / non-DHP CCBs (verapamil, diltiazem) → bradycardia / AV block synergy
  • Other QT-prolonging drugs → additive QT / torsades context (lower torsades rate than dofetilide/sotalol but not zero)
  • CYP3A4 / P-gp substrates and inhibitors (broad) — review high-risk coprescriptions (simvastatin, cyclosporine, tacrolimus, colchicine, etc.) per pharmacy protocol

Special populations

Pediatrics

Specialist / protocol-based only

Pregnancy

Pregnancy: fetal thyroid/neurodevelopmental risks — use only when maternal arrhythmia benefit clearly outweighs risk; Maternal–Fetal Medicine + cardiology co-management.

Lactation

excreted in milk; breastfeeding usually discouraged — institutional policy.

Renal impairment

No major dose adjustment for renal clearance alone — toxicity monitoring still mandatory.

Hepatic impairment

Monitor closely — hepatic accumulation / injury risk; dose/pathway adjustment in severe impairment per specialist.

Elderly

Higher bradycardia / conduction disease risk — lower infusion rates, aggressive rhythm/BP monitoring, avoid polypharmacy stacks.

Administration

- IV: controlled infusion; avoid rapid bolus except ACLS shock-refractory pathway; monitor BP and rhythm continuously early - PO: take consistently; chronic therapy requires scheduled thyroid/LFT/pulmonary surveillance - Peripheral IV compatibility and concentration limits — follow pharmacy protocol

Monitoring

  • Monitor: - ECG / rhythm (QT, AV conduction) - Liver function - Thyroid function - Pulmonary symptoms / CXR or imaging per protocol - BP during IV loading
  • Recheck: - Baseline then periodic thyroid and liver panels on chronic therapy - Ongoing telemetry / rhythm checks in acute IV phases - Reassess INR frequently if on warfarin during initiation or dose changes
  • Hold if:
    - Severe bradycardia
    - Clinically significant QT prolongation / torsades pattern
    - Suspected pulmonary toxicity
    - Significant LFT elevation or clinical hepatitis

Overdose / toxicity

Clinical Picture

Bradycardia Hypotension Torsades / polymorphic VT (context-dependent) Progressive conduction failure

Immediate Actions

Stop infusion / hold oral dose Supportive care ECG monitoring Correct K/Mg; pacing as indicated per protocol

Antidote

None specific — supportive care; pacing / magnesium per arrhythmia protocol

Decontamination

Acute massive oral ingestion: supportive care; prolonged absorption possible — toxicology consult.

Escalation

Shock-refractory arrhythmia, cardiogenic collapse, or end-organ failure → ICU / EP / CV surgery pathways.

Clinical pearls

Common mistakes, resistance logic, and bedside traps

High-Yield

  • Extremely long half-life → toxicity and interactions persist weeks
  • One of few antiarrhythmics often usable in structural heart disease — still organ-toxic

Clinical

  • Baseline thyroid + liver before chronic therapy; repeat on schedule
  • IV hemodynamics ≠ oral outpatient titration mindset

Safety

  • Pulmonary toxicity = early cough/dyspnea — investigate; do not attribute to ‘HF only’

Pharmacy Tool

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Amiodarone 5 mg/mL oral suspension

suspension · oral

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Pharmacokinetics

- Highly lipophilic - Large volume of distribution - Very long elimination (weeks) - Hepatic metabolism with many CYP interactions

Mechanism of action

- Multi-channel blockade (Class I, II, III, IV pharmacologic effects)

Common brand names

Saudi Arabia

Cordarone, Amiodar

Global

Pacerone, (placeholder — verify local formulation)

Common trade names are curated examples only — formulations and availability vary. Verify the exact product name with your local pharmacy and national regulator before prescribing or dispensing.

Country practice notes

Global data (no country-specific data available)

  • Follow local antimicrobial stewardship policy, hospital formulary, and national resistance guidance.
  • Confirm dosing, stock, and restrictions with institutional pharmacy and current product labeling.

References

Saudi Arabia

  • SFDA (Saudi Food & Drug Authority)
  • Saudi National Formulary / MOH (where available)

International

  • WHO Model List of Essential Medicines (verify current edition)
  • US FDA or EU EMA product information (when national SmPC is unavailable)
  • AHA ACLS / cardiac arrest algorithms (refractory VF/VT)
  • ACC / AHA / HRS ventricular arrhythmia and AF management references (where applicable)
  • FDA / SFDA product labeling (IV and oral)