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/excessive supine hypertension. 1

Absolute Contraindications

• Severe organic heart disease - Midodrine can increase peripheral vascular resistance which may worsen cardiac conditions
• Acute renal disease - May affect drug clearance and increase risk of adverse effects
• Urinary retention - Midodrine can worsen urinary retention through increased sphincter tone 2
• Pheochromocytoma - Risk of dangerous hypertensive crisis due to alpha-adrenergic stimulation
• Thyrotoxicosis - May potentiate cardiovascular effects
• Persistent and excessive supine hypertension - Midodrine can significantly worsen supine hypertension 1

Relative Contraindications/Use with Caution

Cardiovascular Conditions

• Congestive heart failure (CHF) - Use cautiously as midodrine may be poorly tolerated 3
• Patients using negative chronotropic agents - Beta-blockers, digoxin, and non-dihydropyridine calcium channel blockers can interact with midodrine, potentially causing bradycardia 3

Urologic Considerations

• History of urologic problems - Midodrine increases vesical sphincter tone and may lead to progressive urinary retention, particularly in patients with spinal cord injury 2
• Patients using alpha-adrenergic blockers - Midodrine can antagonize the actions of medications like terazosin, prazosin, and doxazosin, potentially resulting in urinary retention 3

Medication Interactions

• Concomitant use with other alpha-adrenergic agents - Medications such as ephedrine, pseudoephedrine, and phenylpropanolamine should be avoided as they may aggravate supine hypertension 3

Special Populations

Dialysis Patients

• While midodrine is used to prevent intradialytic hypotension, it should be used with caution as it may be associated with higher risks of cardiovascular events, hospitalization, and mortality in these patients 3
• Midodrine is effectively cleared by hemodialysis with its half-life reduced to 1.4 hours during dialysis 3

Neurologic Conditions

• In patients with cardiac amyloidosis, severe autonomic dysfunction requiring midodrine that cannot be weaned may be a contraindication to heart transplantation 3

Monitoring Requirements

When prescribing midodrine, patients should be monitored for:

• Supine hypertension - Occurs in up to 10% of patients on long-term therapy and warrants cessation of treatment 3, 4
• Bradycardia - Due to reflex parasympathetic stimulation 3
• Urinary retention - Particularly in patients with pre-existing urologic conditions 2

Risk Mitigation Strategies

• Administer the last daily dose at least 4 hours before bedtime to reduce the risk of supine hypertension 5
• Start with lower doses (2.5 mg) and titrate based on symptoms and blood pressure response 3
• In dialysis patients, administer 30 minutes before dialysis sessions to improve intradialytic and postdialytic blood pressure 3

By carefully screening for contraindications and monitoring for adverse effects, midodrine can be safely used in appropriate patients with orthostatic hypotension.