- Write for generic Diltiazem ER to allow pharmacist to substitute between multiple similar ER preparations
- (2016) Presc Lett 23(7): 39-40
- Non-Dihydropyridine Calcium Channel Blocker
- AV Node effects
- Less negative hemodynamic effects than Verapamil
- Potent negative chronotropic effect with decreased Heart Rate (but less than with Verapamil)
- Minimal negative inotropic effect
- Decreases Afterload via peripheral arterial vasodilation
- Diltiazem affects Left Ventricular Dysfunction less than Verapamil
- Coronary vasodilatation
- Prevents sympathetic induced Coronary Artery spasm
- May reduce Anginal episodes and increase Exercise tolerance in Stable Angina
-
Hypertension
- Consider Dihydropyridine Calcium Channel Blocker (e.g. Amlodipine) instead if Heart Rate control not needed
-
Atrial Fibrillation with Rapid Ventricular Response
- Highly effective at controlling ventricular rate
- Paroxysmal Supraventricular Tachycardia
-
Supraventricular Tachycardia
- Terminates AV Node reentry Tachycardias
-
Wolff-Parkinson-White Syndrome with Atrial Fibrillation
- Paroxysmal accelerated ventricular response
- Risk of progression into Ventricular Fibrillation
-
Wide Complex Tachycardia (unless supraventricular)
- Risk of severe Hypotension
- May progress into Ventricular Fibrillation
- Sinus Node or AV Node dysfunction without Pacemaker
- Severe Congestive Heart Failure or pulmonary congestion
- Concurrent Intravenous Beta Blocker use
- Hypotension
- Rapid Atrial Fibrillation or PSVT
- Regimen 1: One Bolus and then maintenance
- Bolus: 0.25 mg/kg (to 20 mg) IV over 2 minutes
- Maintenance: 10 mg/hour titrated to Heart Rate (typically 5-15 mg/hour)
- Mnemonic: Rule of 15 for patient weight of 70 kg
- First: 15 mg IV over 2 minutes, then infusion at 15 mg/hour
- Titrate dosing between 5 to 15 mg/hour
- Regimen 2: Two boluses and then maintenance
- Bolus One: 0.25 mg/kg (to 20 mg) IV over 2 minutes
- Bolus Two: 0.35 mg/kg (to 25 mg) IV over 2 minutes starting 15 minutes after first bolus
- Maintenance: 10 mg/hour titrated to Heart Rate (typically 5-15 mg/hour)
- Regimen 3: Hypotensive patient
- "Bolus": 2.5 mg/min over 10-20 min infusion
- Maintenance: 5 mg/hour titrated as Blood Pressure allows to Heart Rate (typically 5-15 mg/hour)
- Pretreating with Calcium is unlikely to benefit Blood Pressure
- At best may offer transient Blood Pressure increase for 10 minutes (secondary to Catecholamine surge)
- Calcium infusion could be considered in Hypocalcemia (e.g. Calcium Chloride 0.5 to 1 g IV)
- Kolkebeck (2004) J Emerg Med 26(4): 395-400 [PubMed]
- Oral dosing after intravenous rate control
- Consider switching to Beta Blocker for chronic rate control (more efficacious than oral Diltiazem)
- Diltiazem regular release starting at 30-60 mg orally three to four times daily
- Titrate 120 to 360 mg orally daily with extended release
- Hypertension in Adults
- Regular Release
- Start 30 mg orally three times times daily
- Maximum 360 mg/day
- Extended Release
- Long-acting formulations have variable release mechanisms and dosing regimens vary between products
- Extended Release (XR, XT, CD) formulations are dosed once daily
- Sustained Release (SR) formulations are dosed twice daily
- Extended release capsule contents may be sprinkled on food
- Start 120-240 mg orally daily
- Target: 240 to 360 mg/day
- Maximum: 540 mg/day
- Long-acting formulations have variable release mechanisms and dosing regimens vary between products
- Hypertension in Children (Not FDA approved)
- Regular Release
- Start 1.5 to 2 mg/kg/day orally divided 3 to 4 times daily
- Maximum 3.5 mg/kg/day
- Onset in 2-7 minutes after IV infusion
- Bioavailability 50% after oral dose
- Protein bound 75%
- Half-Life 3 hours with active metabolites
- Decrease dose in renal disease
- Accumulation risk with liver Impairment
- Agents that prolong AV Node conduction (avoid)
- Beta Blockers
- Digoxin
- Clonidine (case reports of severe episodes)
- Ivabradine (contraindicated in combination)
- Agents that have levels increased by Diltiazem
- Propranolol
- Buspirone
- Lovastatin (limit to 20 mg daily)
- Simvastatin (limit to 10 mg daily)
- Quinidine
- Agents that increase Diltiazem Levels
- Pregnancy Category C
- Safe in Lactation
- Diltiazem Tablet Extended Release (DailyMed)
- Diltiazem Injection Solution (DailyMed)
- (2022) Presc Lett 29(11): 64-5
- (2022) Presc Lett, Resource #381108, Comparison of Calcium Channel Blockers
- (2020) Med Lett Drugs Ther 62(1598): 73-80
- Olson (2020) Clinical Pharmacology, Medmaster Miami, p. 70-1
- Hamilton (2020) Tarascon Pocket Pharmacopoeia