What are the contraindications for midodrine?

Midodrine Contraindications

Midodrine is contraindicated in patients with severe organic heart disease, acute renal disease, urinary retention, pheochromocytoma, thyrotoxicosis, and persistent and excessive supine hypertension. 1

Absolute Contraindications

• Severe organic heart disease - Midodrine should not be used in patients with significant cardiac disease due to potential cardiovascular effects 1
• Acute renal disease - Contraindicated due to altered drug clearance and increased risk of adverse effects 1
• Urinary retention - Midodrine can worsen urinary retention through increased alpha-1 adrenergic tone at the vesical sphincter 1, 2
• Pheochromocytoma - Contraindicated due to risk of severe hypertensive crisis from alpha-adrenergic stimulation 1
• Thyrotoxicosis - Contraindicated due to potential exacerbation of hypertension and tachycardia 1
• Persistent and excessive supine hypertension - Midodrine can significantly worsen supine hypertension 1, 3

Relative Contraindications and Precautions

• Congestive heart failure - Use with caution due to potential cardiovascular effects 4
• Patients on negative chronotropic agents - Caution with concomitant use of beta-blockers, digoxin, and non-dihydropyridine calcium channel blockers due to risk of bradycardia 5, 4
• Pre-existing bradycardia - Monitor closely as midodrine can cause reflex parasympathetic stimulation 5, 4
• Neurologic contraindication for heart transplantation - Severe autonomic dysfunction requiring midodrine/droxidopa that cannot be weaned 5
• Spinal cord injury patients who void spontaneously - May develop insidious urologic adverse effects including worsening of detrusor-sphincter dyssynergia 2

Drug Interactions to Avoid

• Other alpha-adrenergic agents - Concomitant use with ephedrine, pseudoephedrine, and phenylpropanolamine should be avoided as this may aggravate supine hypertension 5, 4
• Alpha-adrenergic blockers - Can antagonize the actions of alpha-adrenergic blockers (terazosin, prazosin, doxazosin) and could result in urinary retention 5, 4

Monitoring Recommendations

• Blood pressure monitoring - Discontinue therapy if supine systolic hypertension exceeds 180 mmHg or diastolic exceeds 110 mmHg 4
• Urinary function - Monitor for signs of urinary retention, particularly in patients with spinal cord injury or neurogenic bladder 2
• Heart rate - Monitor for bradycardia, especially in patients taking other negative chronotropic medications 5, 4

Special Considerations

• Timing of doses - Last dose should be taken at least 4 hours before bedtime to minimize risk of supine hypertension 4, 6
• Dialysis patients - Midodrine is effectively cleared by hemodialysis with a reduced half-life of 1.4 hours 5
• Elderly patients - May be more sensitive to alpha-adrenergic effects and require closer monitoring 6

By understanding these contraindications and taking appropriate precautions, clinicians can safely prescribe midodrine for appropriate indications while minimizing adverse effects.