Is Cardizem (Diltiazem) safe for patients with possible ileus?

Diltiazem Should Be Avoided in Patients with Possible Ileus

Diltiazem should be avoided in patients with possible ileus due to its potential to worsen intestinal motility and cause paralytic ileus. 1, 2

Mechanism and Risk

• Calcium channel blockers (CCBs) like diltiazem can diminish the contractility of gut smooth muscle, potentially exacerbating or causing clinically significant inhibition of gut motility 2
• Case reports have documented paralytic ileus directly associated with diltiazem use, with symptoms resolving after medication discontinuation 1
• Severe cases of diltiazem overdose have been associated with paralytic intestinal pseudo-obstruction requiring intensive intervention 3

Clinical Considerations for Patients with Possible Ileus

• Patients with ileus are at risk for erratic absorption of oral medications, which can lead to medication accumulation followed by bolus release when gut motility returns 4
• This medication accumulation can result in potentially dangerous overdose effects when gut motility resumes 4
• Patients with intestinal dysmotility may require alternative medications for rate control or other cardiovascular indications 5

Alternative Medications for Common Diltiazem Indications

For Atrial Fibrillation/SVT Rate Control:

• Beta-blockers (if not contraindicated) are preferred first-line agents for rate control in patients with possible ileus 5
• In patients with contraindications to beta-blockers but without ileus, diltiazem would normally be considered appropriate 5
• For patients with both beta-blocker contraindications AND ileus, consider:
  • Digoxin (with appropriate monitoring) 5
  • Amiodarone (for refractory cases, with careful monitoring) 5

For Hypertension:

• ACE inhibitors or ARBs are preferred if the patient has evidence of LV dysfunction, heart failure, or diabetes mellitus 5
• Long-acting dihydropyridine CCBs (amlodipine, felodipine) may be better tolerated than non-dihydropyridine CCBs (diltiazem, verapamil) in patients with intestinal issues, though caution is still warranted 5
• Thiazide diuretics can be considered for long-term control if there are no contraindications 5

Management of Patients Already on Diltiazem with Suspected Ileus

• If a patient on diltiazem develops symptoms of ileus (abdominal distention, absence of bowel sounds, nausea, vomiting, constipation), consider discontinuation of diltiazem 1
• Monitor for rapid symptomatic improvement of gastrointestinal symptoms after discontinuation, which would support diltiazem as the causative agent 1, 2
• Implement appropriate supportive care for ileus, including nasogastric decompression if needed 1

Special Considerations

• Patients with small intestinal dysmotility may be particularly susceptible to the motility-inhibiting effects of calcium channel blockers 5
• The risk of complications appears to be dose-dependent, with higher doses of diltiazem carrying greater risk 1, 3
• Patients with multiple comorbidities and polypharmacy may be at increased risk for this adverse effect 1

In summary, given the documented cases of diltiazem-induced paralytic ileus and the potential for serious complications, alternative medications should be selected for patients with known or suspected ileus.