Prazosin: a potential new management tool for iatrogenic autonomic dysreflexia in individuals with spinal cord injury?

Neural Regeneration Research, 2015 · DOI: 10.4103/1673-5374.155422 · Published: April 1, 2015

Spinal Cord Injury Pharmacology Neurology

Simple Explanation

Spinal cord injury (SCI) is a devastating condition that not only results in a loss of motor functions but also severe autonomic dysfunctions. Autonomic dysreflexia (AD) is a life threatening episode of transient hypertension that occurs up to 30x/day (11x/day on average) in those with cervical or high thoracic SCI. Prazosin did not result in a decrease in resting BP, suggesting it may be a viable alternative for mitigating AD severity, with particular benefit in patients suffering from persistent hypotension.

Study Duration

Not specified

Participants

Six patients with complete chronic SCI (> 2 years)

Evidence Level

Not specified

Key Findings

1
Patients experienced a significantly smaller increase in SBP after ejaculation after being administered prazosin compared to placebo (97 ± 34 mmHg vs. 141 ± 46 mmHg, P = 0.02)
2
No difference in resting BP between prazosin and placebo trials
3
1 mg prazosin (administered orally once the night before, and once 2 hours prior to ejaculation) is effective at reducing the severity of iatrogenically-induced AD in those with SCI during PVS.

Research Summary

Prazosin is a selective α-adrenergic blocker that preserves the vasoactive actions of the RAS pathways, exerting a less abrupt suppressive effect on resting BP. A clinical trial showed prazosin reduced the severity of iatrogenically-induced AD due to PVS without decreasing resting BP, suggesting it's a viable alternative, especially for patients with persistent hypotension. Administering the first dose of prazosin before nighttime sleep can mitigate the risk of severe orthostatic hypotension.

Practical Implications

Alternative AD Management

Prazosin offers a potential alternative to nifedipine for managing AD, particularly beneficial for SCI patients with persistent hypotension.

Mitigation of First-Dose Phenomenon

Administering the initial dose of prazosin at bedtime can reduce the risk of severe orthostatic hypotension.

Further Research Needed

Larger clinical trials using ambulatory BP monitoring are needed to further establish prazosin's efficacy in prophylactic AD management.

Study Limitations

1
Small sample size (6 patients)
2
Risk of 'first-dose phenomenon' (severe drop in BP upon initial administration)
3
Need for larger clinical trials with more sophisticated BP measurements

Your Feedback

Was this summary helpful?

Back to Spinal Cord Injury