Nitroglycerin Patch Dosing for Angina Pectoris
For stable angina, use a nitroglycerin patch delivering 0.2-0.8 mg/hour applied for 12-14 hours daily, then remove it for a 10-12 hour nitrate-free interval to prevent tolerance. 1, 2
Starting Dose and Titration
- Begin with a 0.2 mg/hour patch (5 mg/24 hours) applied in the morning 2, 3
- Titrate upward to 0.4,0.6, or 0.8 mg/hour (10-20 mg/24 hours) based on symptom control 2, 3
- Doses of 0.6-0.8 mg/hour (15-20 mg/24 hours) are usually optimal for most patients 3
- Patches delivering ≥10 mg over 24 hours provide classic nitrate effects in angina patients 4
Critical Dosing Schedule: The Tolerance Problem
The most important aspect of patch therapy is intermittent dosing—continuous 24-hour application leads to complete tolerance and loss of efficacy. 1, 4, 3
Recommended Application Schedule:
- Apply patch for 12-14 hours consecutively (typically morning application) 1, 4
- Remove patch for 10-12 hours (typically overnight) 1, 4
- This intermittent approach eliminates or markedly reduces nitrate tolerance 4
- Continuous 24-hour therapy loses efficacy by 24 hours in acute dosing 4
- With chronic continuous dosing, patches have little advantage over placebo 4, 5
Timing Considerations Based on Angina Pattern
For patients with predominantly daytime, effort-induced angina:
- Apply patch in the morning, remove at bedtime 6
- This optimizes nitrate sensitivity during daytime when most attacks occur 6
- Most patients with effort angina experience few nocturnal attacks 7
For patients with frequent nocturnal or rest angina:
- Continuous 24-hour therapy may be considered despite tolerance risk 3
- About 50% of patients with rest or "mixed" angina have nocturnal episodes 7
- However, be aware that efficacy will be reduced compared to intermittent dosing 3
- Rebound phenomena are not a problem with continuous therapy 3
Expected Efficacy and Monitoring
- Exercise duration to onset of angina improves significantly at 4 hours post-application 5
- Effects are typically strongest 2-5 hours after patch application 3
- Little to no effect is seen at the end of the 24-hour application period with continuous use 3
- Anginal attack rates can be reduced by approximately 67-71% with proper dosing 7
- The proportion of angina-free patients increases from 12-15% to 49-54% 7
Common Pitfalls to Avoid
Do not use continuous 24-hour patch application—this is the most common error and leads to complete tolerance development within 24 hours 1, 4, 5
Do not underdose—patches delivering less than 10 mg/24 hours (approximately 0.4 mg/hour) may not provide adequate nitrate effects 4
Monitor for first-dose response—patients with very low initial response to nitrates are less likely to benefit from patch therapy and may be better candidates for alternative antianginal agents 3
Side Effects and Contraindications
- Headache is the most common side-effect 7
- Dose-dependent vasodilator effects include flushing and potential postural hypotension 1
- Absolute contraindication: phosphodiesterase-5 inhibitor use within 24 hours (sildenafil/vardenafil) or 48 hours (tadalafil) due to risk of profound hypotension, MI, and death 8, 9, 2
- Avoid in patients with systolic blood pressure <90 mmHg 9, 2
- Withdrawals due to side-effects are rare (approximately 1.5%) 7
Comparison with Other Nitrate Formulations
- Transdermal patch efficacy is comparable to oral nitrates when dosed appropriately 3
- Patches offer convenience and cosmetic acceptability over ointment formulations 6
- For acute angina attacks, patients still require sublingual nitroglycerin for immediate relief 1
- Short-acting nitrate consumption serves as a good measure of patch treatment effectiveness 1