What is the recommended usage and treatment plan for a patient with a history of angina pectoris (chest pain) using nitro paste (nitroglycerin paste)?

Nitroglycerin Paste for Angina Pectoris

Nitroglycerin ointment is indicated for the prevention of angina pectoris due to coronary artery disease, but it is NOT sufficiently rapid-acting to abort an acute anginal episode. 1

Dosing and Application

Start with 1/2 inch (7.5 mg) applied twice daily—once upon waking and again 6 hours later—to allow a mandatory 10-12 hour nitrate-free interval overnight. 1

• The dose can be doubled to 1 inch (15 mg) twice daily, and doubled again to 2 inches (30 mg) twice daily in patients who tolerate but fail to respond to lower doses 1
• Apply the ointment to approximately 36 square inches (232 square centimeters) of truncal skin using the provided paper applicator 1
• The ointment provides effective anti-anginal activity for up to 7 hours after a single application 1

Critical Timing Requirement: The Nitrate-Free Interval

You must include a 10-12 hour nitrate-free interval each day, typically overnight, or all anti-anginal efficacy will be lost within 24 hours due to nitrate tolerance. 1

• Tolerance develops within 7-8 hours and becomes clinically significant after 24 hours of continuous therapy 2
• This tolerance cannot be overcome by dose escalation, even with doses far exceeding those used acutely 1
• The twice-daily dosing schedule (morning and 6 hours later) ensures the patient is covered during waking hours when angina is most likely, while allowing overnight tolerance reversal 1

Acute Angina Management

For acute anginal episodes, patients must use sublingual nitroglycerin or nitroglycerin spray, NOT the ointment. 3

• Instruct patients to take 1 dose of sublingual nitroglycerin at the onset of chest pain 3
• If chest pain is unimproved or worsening after 5 minutes, the patient or caregiver should call 9-1-1 immediately before taking additional nitroglycerin 3
• In patients with chronic stable angina whose symptoms significantly improve with the first dose, they may repeat nitroglycerin every 5 minutes for a maximum of 3 doses, calling 9-1-1 if symptoms have not completely resolved 3

Patient Education Requirements

Before discharge, provide both verbal and written instructions covering: 3

• The purpose of nitroglycerin ointment is prevention, not acute treatment 1
• How to recognize worsening angina patterns (more frequent, more severe, precipitated by less effort, or occurring at rest) that require immediate contact with their clinician 3
• When to call 9-1-1: if initial angina lasts more than 1 minute and does not subside within 3-5 minutes of sublingual nitroglycerin 3
• Common side effects: headache and postural hypotensive symptoms (dizziness upon standing) 4

Contraindications and Precautions

Absolute contraindication exists if the patient has used sildenafil within 24 hours or tadalafil/vardenafil within 48 hours due to risk of profound hypotension and death. 2

• Avoid in patients with systolic blood pressure <90 mmHg 2
• Avoid in patients with marked bradycardia (<50 bpm) or tachycardia (>100 bpm without heart failure) 2
• Overdosing may cause postural hypotension and reflexogenic tachycardia, leading to "paradoxical" angina 3

Long-Term Considerations

Nitroglycerin ointment should be combined with comprehensive secondary prevention medications: 3

• Aspirin 81-325 mg daily (or clopidogrel if aspirin contraindicated) 3
• Beta-blocker, particularly if the patient has had a prior myocardial infarction 3
• Statin therapy for LDL cholesterol lowering 3
• ACE inhibitor, especially if hypertension, heart failure, LV dysfunction, prior MI, or diabetes is present 3

The maximal achievable daily duration of anti-anginal effect from nitroglycerin ointment is approximately 12 hours, making the twice-daily regimen with overnight nitrate-free interval the optimal approach. 1