Is diltiazem available in a liquid form?

Availability of Diltiazem in Liquid Form

Diltiazem is available in various formulations including immediate-release tablets, extended-release capsules, and intravenous forms, but it is not commercially available in a liquid oral formulation. 1

Available Formulations of Diltiazem

• Diltiazem is primarily available as:

  • Immediate-release tablets (30-90 mg doses) 2
  • Extended-release capsules (120-360 mg doses) 1
  • Intravenous solution for hospital administration (0.25 mg/kg IV bolus) 2, 3

• For intravenous administration, diltiazem is available as a solution that can be administered as:

  • IV bolus (0.25 mg/kg over 2 minutes) 2
  • IV infusion (5-15 mg/hour) for continuous administration 2

Clinical Implications

• The lack of a commercially available liquid oral formulation may present challenges for:

  • Patients with difficulty swallowing tablets or capsules 1
  • Patients requiring administration through feeding tubes 1
  • Pediatric patients requiring weight-based dosing 3

• For patients unable to swallow tablets or capsules, alternative calcium channel blockers or medication classes may need to be considered 1

• When IV diltiazem is needed, it should be administered with caution due to potential adverse effects:

  • Hypotension (especially with rapid administration) 4
  • Worsening heart failure in patients with pre-existing ventricular dysfunction 2
  • Bradycardia and conduction disturbances 3

Administration Considerations

• For patients requiring IV diltiazem, a lower initial dose (≤0.2 mg/kg) may be as effective as the standard dose (0.25 mg/kg) while reducing the risk of hypotension 4

• Diltiazem has incomplete bioavailability (approximately 44%) after oral administration, primarily due to first-pass hepatic metabolism 5

• The dose of diltiazem typically required for hypertension (commonly 360 mg/day) is greater than that required for angina (commonly 240 mg/day) 6

Contraindications and Precautions

• Diltiazem should be avoided in patients with:

  • AV block greater than first degree or SA node dysfunction (without pacemaker) 2, 1
  • Decompensated systolic heart failure or severe LV dysfunction 1
  • Wolff-Parkinson-White syndrome with atrial fibrillation/flutter 1
  • Cardiogenic shock 2

• Caution should be exercised when using diltiazem in patients with:

  • Hepatic or renal dysfunction 2
  • Concurrent use of medications that affect SA/AV nodal conduction 2, 1