What are the blood pressure parameters to hold Cardizem (Diltiazem)?

Blood Pressure Parameters for Holding Cardizem (Diltiazem)

Cardizem (diltiazem) should be held if the blood pressure is less than 90/60 mmHg due to its hypotensive effects and potential for causing hemodynamic compromise. 1

Mechanism and Effects on Blood Pressure

Diltiazem is a calcium channel blocker that:

• Decreases peripheral vascular resistance and causes a modest fall in blood pressure 1
• Reduces heart rate-blood pressure product during exercise in patients with ischemic heart disease 1
• Can cause significant hypotension when blood pressure is already low 1

Specific Blood Pressure Parameters for Holding Diltiazem

Lower Limits

• Systolic BP < 90 mmHg: Diltiazem is contraindicated in patients with hypotension (less than 90 mm Hg systolic) 1
• Diastolic BP < 60 mmHg: Caution is advised when diastolic BP falls below 60 mmHg, especially in patients with coronary artery disease 2

Special Considerations

• Patients with coronary heart disease: Extra caution is warranted as low diastolic BP (below 70 mmHg) is associated with increased cardiovascular events 3
• Elderly patients: While diltiazem is effective in patients 55 years or older, monitoring for hypotension is particularly important in this population 4

Monitoring Recommendations

• Check blood pressure before each dose of diltiazem 2
• For patients on extended-release formulations (e.g., Cardizem CD), monitor blood pressure at trough effect (just before next scheduled dose) 2
• If systolic BP falls below 90 mmHg or diastolic BP below 60 mmHg, hold the medication and notify the prescriber 1, 2

Rationale for Blood Pressure Parameters

• Hypotension (SBP < 90 mmHg) is a contraindication for diltiazem use according to FDA labeling 1
• Low diastolic blood pressure (< 60 mmHg) can compromise coronary perfusion, particularly in patients with coronary artery disease 2, 3
• Excessive blood pressure reduction may lead to adverse outcomes, including:
  • Increased risk of cardiovascular events in patients with coronary heart disease 3
  • Potential for syncope, dizziness, and falls, especially in elderly patients 4

Resumption Guidelines

• Once blood pressure has returned to acceptable parameters (SBP ≥ 90 mmHg and DBP ≥ 60 mmHg), diltiazem may be resumed 1
• Consider dose reduction if hypotension was significant or recurrent 1
• For patients with coronary heart disease, maintaining diastolic BP above 70 mmHg may be preferable 3

Common Pitfalls

• Failure to check blood pressure before administration of diltiazem 2
• Not recognizing the additive hypotensive effects when diltiazem is combined with other antihypertensive medications, particularly beta-blockers 2
• Overlooking orthostatic hypotension, which may be more pronounced with diltiazem therapy 2
• Ignoring symptoms of hypotension (dizziness, lightheadedness) even when measured BP appears adequate 1