Nitroglycerin Patch Dosing
Nitroglycerin transdermal patches are dosed at 0.2 to 0.8 mg/hour, applied for 12-14 hours daily with a mandatory 10-12 hour nitrate-free interval to prevent tolerance. 1
Standard Dosing Regimen
- Start with 0.2 mg/hour patches and titrate up to 0.8 mg/hour based on clinical response 1
- Apply patches in the morning (typically 8 AM) and remove them in the evening (6-10 PM) to create a 10-12 hour nitrate-free interval 2, 3
- The maximum recommended dose is 0.8 mg/hour every 12 hours 1
- Duration of effect is approximately 8-12 hours during intermittent therapy 1
Critical Dosing Principle: Intermittent vs Continuous Therapy
Intermittent patch therapy with a nitrate-free interval is superior to continuous 24-hour application. 4, 5 The evidence strongly demonstrates:
- Continuous 24-hour patch application leads to complete tolerance development within 24-48 hours, rendering the medication ineffective 6, 7
- Studies using continuous therapy (15-105 mg/24 hours) showed no superiority over placebo after 2-8 weeks 4, 7
- Intermittent therapy with overnight nitrate-free intervals maintains antianginal efficacy during sustained use 3, 5
- Tolerance is dose and duration dependent, becoming significant after 24 hours of continuous exposure 2, 1
Tolerance Management Strategy
- Remove patches after 12-14 hours to create a mandatory nitrate-free interval 2, 3
- This prevents the complete loss of efficacy seen with continuous therapy 5, 7
- Even with intermittent therapy, some attenuation of initial effects may occur, but clinically meaningful benefit is maintained 4
- For patients requiring continuous coverage (frequent nocturnal angina), accept that continuous therapy may retain only minimal effect 4
Safety Parameters and Contraindications
Do not use nitroglycerin patches if: 2, 1
- Systolic blood pressure <90 mmHg or >30 mmHg below baseline 2, 1
- Patient has taken sildenafil within 24 hours or tadalafil within 48 hours (risk of profound hypotension and death) 2, 1
- Suspected right ventricular infarction (these patients are critically dependent on preload) 2, 1
- Marked bradycardia or tachycardia present 1
Clinical Context for Patch Selection
- Patches are appropriate for patients with stable angina requiring prophylaxis, particularly those with exercise-induced symptoms 4
- For acute coronary syndromes or refractory ischemia, intravenous nitroglycerin (starting at 10 mcg/min, titrated up to 200 mcg/min) is preferred over patches 8, 2
- Patients with frequent nocturnal angina may benefit from continuous patch therapy despite reduced efficacy, as rebound phenomena are avoided 4
- Patients with exercise-only angina and low first-dose nitrate response benefit more from intermittent therapy 4