GTN Use in ICH with Hypertension
GTN (glyceryl trinitrate) should NOT be used for blood pressure management in patients with intracerebral hemorrhage and hypertension, as it is not recommended by major guidelines and may cause harm, particularly when administered as transdermal patches. 1
Guideline Recommendations Against GTN
The American Heart Association explicitly recommends against using GTN patches for managing hypertensive crisis in patients with intracerebral hemorrhage due to unpredictable blood pressure responses and potential for harm. 1 This recommendation is based on several critical concerns:
GTN patches have unpredictable blood pressure responses and a prolonged duration of action, making them unsuitable for acute hypertensive crisis management where precise titration is essential. 1
The patch formulation cannot be easily titrated to achieve specific blood pressure targets, which is critical in hypertensive emergencies. 1
GTN is not listed among recommended first-line agents for hypertensive emergencies in major guidelines from the American Heart Association. 1
Evidence of Harm
The RIGHT-2 trial provides concerning evidence: GTN use in patients with intracerebral hemorrhage resulted in greater hematoma growth and poorer outcomes compared to controls in 145 patients who received GTN patches. 1 This finding directly contradicts the therapeutic goal of preventing hematoma expansion in acute ICH.
Recommended Alternatives
For hypertensive emergencies in ICH, use intravenous agents such as labetalol or nicardipine with continuous monitoring in an ICU setting. 1 The 2022 Stroke guidelines indicate that:
α- and β-adrenoreceptor blockers (like labetalol) appear to have better outcomes from active/intensive BP lowering compared with calcium channel blockers, nitrates, and other agents. 2
Labetalol IV is the first-line treatment for ACV hemorrágico (hemorrhagic stroke), with urapidil and nicardipina as alternatives. 1
Specific Concerns with GTN in ICH
Intracranial Pressure Effects
While older research from 1992 suggested that NTG caused remarkable increases in ICP in patients with normal intracranial compliance but no elevation in those with poor compliance, 3 this does not justify its use given:
- The unpredictability of which patients will experience ICP elevation
- The inability to rapidly reverse effects with transdermal formulation
- Availability of safer, more titratable alternatives
Blood Pressure Lowering Efficacy
The ENOS trial subgroup analysis of 629 ICH patients found that GTN lowered blood pressure (difference -7.5/-4.2 mm Hg) but did not improve functional outcome at 90 days. 4 Importantly:
- Only in the very early subgroup (within 6 hours, n=61) did GTN show potential benefit (OR 0.22,95% CI 0.07-0.69). 4
- This finding requires further validation and does not justify routine use given the availability of superior alternatives. 4
Critical Blood Pressure Management Principles
When managing hypertension in ICH:
Reduce mean arterial pressure by 20-25% in the first hour, then to 160/100 mmHg over 2-6 hours for standard hypertensive emergencies. 1
Avoid systolic blood pressure reduction >70 mmHg within 1 hour, as this is associated with poor outcomes in ICH patients. 1
Use intravenous agents that allow precise titration and rapid discontinuation if needed, which is a key distinction that GTN patches cannot provide. 1
Intravenous Nitroglycerin Caveat
If intravenous nitroglycerin (not transdermal GTN) is considered, it has specific indications limited to acute coronary syndrome with ongoing ischemia and acute pulmonary edema/cardiogenic shock, 2 NOT for primary blood pressure management in ICH. Additionally: