Pacet 200

Indications

Pacet tablets are used for serious heart arrhythmias including ventricular fibrillation, ventricular tachycardia, atrial fibrillation, and atrial flutter. Pacet injection is indicated for initiating treatment and preventing recurrent ventricular fibrillation and unstable ventricular tachycardia in patients who do not respond to other therapies.

Pharmacology

Pacet contains Amiodarone Hydrochloride, a broad-spectrum antiarrhythmic agent. It works by affecting the heart’s electrical system, delaying repolarization, and prolonging the action potential. It also slows electrical conduction and reduces heart pacemaker firing rates. Additionally, Amiodarone dilates blood vessels, which can be beneficial for congestive heart failure but may lower blood pressure.

Dosage & Administration

For tablets, start with 200 mg three times daily for one week, then reduce to 200 mg twice daily or the minimum effective dose. It is recommended to take with meals to reduce stomach upset. For injection, begin with 1000 mg over 24 hours. The initial load is 150 mg per 100 mL (in D5W or Normal Saline) infused over 10 minutes, followed by 1 mg/min for 6 hours, and then 0.5 mg/min thereafter. For breakthrough episodes, repeat the initial load and adjust the maintenance infusion rate as needed.

Interaction

Pacet may interact with beta-blockers (e.g., Atenolol, Propranolol), certain calcium channel blockers (e.g., Verapamil, Diltiazem), increasing the risk of a slow heart rate. It can elevate Digoxin levels, increase Flecainide concentrations, and interact with tricyclic antidepressants and Warfarin, increasing bleeding risks. It also inhibits Dextromethorphan metabolism.

Contraindications

Pacet is contraindicated in patients with cardiogenic shock, severe sinus-node dysfunction, second- or third-degree atrioventricular block, and bradycardia-induced syncope (unless using a pacemaker). It is also contraindicated in patients with known hypersensitivity to Amiodarone or iodine.

Side Effects

Serious side effects may include lung toxicity, which can be fatal, liver toxicity, corneal microdeposits, optic neuritis, peripheral neuropathy, bradycardia, and skin discoloration. Other rare effects include nausea, vomiting, metallic taste, tremor, and liver issues. Dose adjustments or discontinuation may be required if severe side effects occur.

Pregnancy & Lactation

Amiodarone is generally not recommended during pregnancy due to risks of thyroid issues in infants. If necessary, the risks to the fetus should be discussed. Its safety during lactation is not established.

Therapeutic Class

Potassium Channel Blockers

Storage Conditions

Store below 30°C, away from light and moisture. Keep out of reach of children.