Diltiazem, Cardizem, Dilacor XR, Tiazac, Cartia XT

Question 1

Diltiazem Class

Answer 1

• Calcium Channel Blocker

* Class IV antidysrhythmic

Question 2

Diltiazem Action

Answer 2

• Inhibits the influx of extracellular Ca++ in cardiac and vascular smooth muscle cells.
• Dilates coronary and systemic arteries.
• Improves oxygen delivery to the myocardial tissue. •Decreases total peripheral resistance.
• Decreases systemic blood pressure.
• Decreases afterload.
• It is a negative dromotrope
• Creates refractoriness in the AV node.
• Effects on calcium channels in SA and AV nodes, and peripheral vasculature are equipotent.

Question 3

Diltiazem Indication

Answer 3

• A-fib/ flutter w/ RVR
• Multifocal atrial tachycardia
• PSVT

Question 4

Diltiazem Contraindication

Answer 4

• 2nd or 3rd degree AV block (in the absence of a
functioning pacemaker)
• SSS (in the absence of a functioning pacemaker)
• Cardiogenic shock
• Hypersensitivity
• A-fin/ flutter with WPW or short PR syndrome (Lown-Ganong-Levine
Syndrome)
• Ventricular tachycardia
• Wide-complex tachycardia of unknown origin
• AMI (associated with CHF or left ventricular
dysfunction)
• Advanced aortic stenosis
• Hypotension (less than 90 mmHg)

Question 5

Diltiazem Precaution

Answer 5

• CHF
• Elderly
• Renal / Hepatic Impairment
• Pregnancy (C)

Question 6

Diltiazem Dosage

Answer 6

Adults:
• IV: 10 mg over 2 min. Repeat q 10-15 min PRN rate control. MAX 40 mg.
Peds:
• (Medical Control Order)
• 0.25 mg/kg IV over 2 min(Usual dose about 20 mg). May repeat in 15 min @ 0.35 mg/kg IV over 2 minutes

Question 7

Diltiazem Onset/ Duration

Answer 7

• Onset: 2-5 minutes

* Duration: 1-3 hours

Question 8

Diltiazem Side Effects

Answer 8

• First or second degree AV block
• Bradycardia
• Ventricular dysrhythmias
• CHF, Edema
• Hypotension
• Syncope
• Flushing
• Chest pain
• Dyspnea
• Sweating
• N/V
• Dizziness
• Nervousness
• Xerostomia
• HA

Question 9

Diltiazem Interactions

Answer 9

• May prolong the sedative effects of midazolam.
• May enhance the effects of ASA and prolong bleeding.
• Additive effects with antihypertensives, alpha-blockers, and diuretics.
• Should not be used in combination with IV BB. The
negative inotropic, chronotropic, and hypotensive effects can induce heart failure.
• Calcium salts can antagonize the hypotensive effects, but do not seem to have an effect on AV conduction.
• Incompatible with simultaneous furosemide injection.