Name

ditiazem (Cardizem®)

Class

Calcium channel blocker

Class IV antidysrhythmic

Description/Mechanism

Diltiazem is a calcium channel blocking agent that slows conduction, increases refractoriness in the AV node, and causes coronary vasodilation. The drug is used to control ventricular response rates in patients with atrial fibrillation, atrial flutter, multifocal atrial tachycardia and PSVT

Onset

2-5 min

Duration

1-3 hours

Indications

Atrial fibrillation

Atril Flutter

Multifocal Atrial Tachycardia

PSVT

Contraindications

Sick sinus syndrome

Second or Third degree AV Block

WPW or other preexcitation syndrom.

VT or wide complex tachycardia or unknown origin

Severe hypotension

Hypersensitivity to diltiazem

Concomitant use of IV beta blockers

Adverse Reactions

A-flutter, first and second degree AV block

Bradycardia, chest pain, congestive heart failure, syncope, ventricular dysrhythmias, sweating, nausea and vomiting, dizziness, dry mouth, dyspnea, headache

Drug Interactions

Caution is warranted in patients receiving medications that affect cardiac contractility and/or SA or AV node conduction

Incompatible with simultaneous furosemide injection

Supplied

25 mg (5 ml vial); 50 mg (10 ml vial)

Dose/Administration

Adult

Bolus

0.25 mg/kg (20 mg for the average patient) IV over 2 min; may be repeated in 15 min (0.35 mg/kg; 25 mg for the average patient) IV over 2 min.

Maintenance

Dilute 125 mg (25 ml) in 100 ml of solution: infuse 5-15 mg/hr, titrated to heart rate.

Special Consideration

Pregnancy Safety: Category C

Use with caution in patients with impaired renal or hepatic function.

Hypotension may occasionally result (watch vital signs carefully)

PVCs may be present on conversion of PSVT to sinus rhythm

Shelf-life at room temperature is one month.