Is verapamil (calcium channel blocker) safe to use in a patient with hemorrhage and hypotension?

Verapamil is Contraindicated in Hemorrhagic Patients with Hypotension

Verapamil is absolutely contraindicated in patients with hemorrhage and hypotension due to its potential to worsen hypotension and cause cardiovascular collapse.

Contraindications for Verapamil Use

• Verapamil is explicitly contraindicated in patients with hypotension (systolic pressure less than 90 mm Hg) or cardiogenic shock according to FDA labeling 1
• Verapamil can cause a significant decrease in blood pressure below normal levels, which may result in dizziness or symptomatic hypotension 1
• In hemorrhagic patients who are already hypotensive, verapamil's vasodilatory effects can further reduce systemic vascular resistance, potentially leading to cardiovascular collapse 2

Mechanism of Concern in Hemorrhagic Patients

• Verapamil reduces cell transmembrane inward calcium flux, which inhibits both myocardial and vascular smooth muscle contraction, leading to vasodilation 2
• In patients with active hemorrhage:
  • The body's compensatory mechanisms (vasoconstriction) are already activated to maintain blood pressure 2
  • Verapamil directly counteracts these compensatory mechanisms by causing vasodilation 1
  • This can precipitate profound hypotension in volume-depleted patients 1

Evidence of Harm

• In patients with sustained ventricular tachycardia who received intravenous verapamil, 44% developed acute severe hypotension or loss of consciousness requiring immediate cardioversion 3
• Cases of anaphylactic shock have been reported with verapamil administration, further highlighting its potential for causing severe hypotension 4
• For patients with obstructive hypertrophic cardiomyopathy and severe dyspnea at rest, hypotension, or very high resting gradients, verapamil is considered potentially harmful 2

Management of Hypotension in Hemorrhagic Patients

• For patients with acute hypotension who do not respond to fluid administration, intravenous phenylephrine (or other vasoconstrictors without inotropic activity) is recommended 2
• In patients with obstructive hypertrophic cardiomyopathy and acute hypotension, a combination of vasoconstrictors with beta-blocking drugs may be used 2
• Fluid resuscitation should be the first-line treatment for hemorrhagic hypotension before considering any medications 2

Alternative Medications in Patients with Contraindications to Verapamil

• If calcium channel blockers are needed for managing conditions like supraventricular tachycardia in patients with contraindications to beta-blockers:
  • Long-acting dihydropyridine calcium channel blockers may be considered in stable patients, but should be used with caution 2
  • However, short-acting dihydropyridine CCBs such as nifedipine can cause severe hemodynamic instability and should never be used unless in combination with an alpha-blocker 2

Conclusion

Verapamil should not be administered to patients with hemorrhage and hypotension under any circumstances. The risk of worsening hypotension and cardiovascular collapse is significant. Alternative treatments should be considered based on the specific clinical indication for which verapamil was being considered.