What Is Nitroglycerin?

Nitroglycerin is a prescription medication that belongs to a class of drugs called organic nitrates. It works by relaxing and widening blood vessels, which improves blood flow and reduces the heart's workload. Nitroglycerin has been used in medicine for over 100 years and remains one of the most important medications for treating chest pain (angina) caused by coronary artery disease.

For a deeper dive into how this medication works at the cellular level, see our article on how Nitroglycerin works.

What Is Nitroglycerin Used For?

Nitroglycerin is FDA-approved for several conditions:

Angina Pectoris (Chest Pain)

This is the primary use of Nitroglycerin. Angina occurs when the heart muscle doesn't receive enough oxygen-rich blood, usually due to narrowed coronary arteries. Nitroglycerin is used in two ways for angina:

• Acute relief — Sublingual tablets and spray provide rapid relief during an angina attack (within 1-3 minutes)
• Prevention — Transdermal patches, sustained-release capsules, and ointment are used to prevent angina episodes from occurring

Chronic Anal Fissure

Rectiv, a 0.4% Nitroglycerin rectal ointment, is FDA-approved for treating chronic anal fissures. It works by relaxing the internal anal sphincter muscle, promoting healing.

Hospital Uses (IV Nitroglycerin)

Intravenous Nitroglycerin is used in hospital settings for:

• Perioperative hypertension (high blood pressure during surgery)
• Acute heart failure and pulmonary edema
• Acute coronary syndromes (heart attacks)

Available Forms and Brand Names

Nitroglycerin comes in several formulations, each designed for specific situations:

Sublingual Tablets

Brand: Nitrostat — Available in 0.3 mg, 0.4 mg, and 0.6 mg strengths. These small tablets are placed under the tongue and dissolve in seconds for rapid relief of acute angina.

Translingual Spray

Brands: Nitrolingual Pumpspray, Nitromist — Delivers 0.4 mg per spray onto or under the tongue. Same rapid-acting purpose as sublingual tablets but in a spray format that some patients find easier to use.

Transdermal Patches

Brands: Nitro-Dur, Minitran — Available in strengths ranging from 0.1 to 0.8 mg/hr. Applied to the skin for continuous Nitroglycerin delivery over 12-14 hours. Used for long-term angina prevention.

Sustained-Release Capsules

Available in 2.5 mg, 6.5 mg, and 9 mg strengths. Taken orally for ongoing angina prevention.

Topical Ointment

Nitro-Bid (2%) for angina; Rectiv (0.4%) for anal fissures.

IV Solution

5 mg/mL concentration for hospital use only.

How to Take Nitroglycerin

Proper use depends on which form you've been prescribed:

Sublingual Tablets (Nitrostat)

1. At the first sign of chest pain, place one tablet under your tongue
2. Let it dissolve completely — do not chew or swallow
3. Sit down while taking the medication to prevent falls from dizziness
4. If pain is not relieved after 5 minutes, take a second tablet
5. If pain persists after a third tablet (15 minutes total), call 911 immediately

Translingual Spray

1. Hold the canister upright and spray onto or under your tongue
2. Use 1-2 sprays (0.4 mg each)
3. Do not inhale the spray
4. Follow the same 5-minute interval and 911 guidelines as sublingual tablets

Transdermal Patches

1. Apply to clean, dry, hairless skin on the chest, upper arm, or shoulder
2. Press firmly for 10-15 seconds to ensure adhesion
3. Rotate application sites daily to prevent skin irritation
4. Wear for 12-14 hours, then remove for a 10-12 hour nitrate-free interval (usually overnight)
5. The nitrate-free period prevents your body from developing tolerance

Typical Dosing

• Sublingual tablets: 0.3-0.6 mg as needed for acute angina. May repeat every 5 minutes, up to 3 doses.
• Spray: 1-2 sprays (0.4 mg each) as needed. Same repeat guidelines as tablets.
• Patches: 0.2-0.8 mg/hr, applied for 12-14 hours with a 10-12 hour patch-free interval.

Your doctor will determine the right dose for you based on your condition and response to treatment. Never adjust your dose without medical guidance.

Important Safety Information

Contraindications

Nitroglycerin should NOT be used if you:

• Take PDE5 inhibitors such as sildenafil (Viagra), tadalafil (Cialis), or vardenafil (Levitra) — this combination can cause severe, life-threatening drops in blood pressure
• Take riociguat (Adempas)
• Have a known allergy to Nitroglycerin or other nitrates
• Have severe anemia, increased intracranial pressure, or right ventricular infarction

Drug Interactions

Nitroglycerin interacts with several medications and substances. The most dangerous interaction is with PDE5 inhibitors. Alcohol also significantly increases the risk of dangerously low blood pressure. For a complete guide, read our article on Nitroglycerin drug interactions.

Side Effects

Common side effects include headache (up to 50% of patients), dizziness, flushing, and nausea. Most are mild and improve over time. For details on managing side effects, see our guide on Nitroglycerin side effects.

Special Populations

• Pregnancy: Category C — use only if the potential benefit justifies the potential risk
• Elderly: Use with caution due to higher risk of hypotension and falls
• Volume-depleted patients: Increased risk of severe hypotension

Storage Requirements

Proper storage is critical for Nitroglycerin, especially sublingual tablets:

• Keep sublingual tablets in the original glass bottle — do not transfer to pill organizers
• Close the cap tightly after each use
• Store at room temperature, away from heat, light, and moisture
• Replace sublingual tablets every 6 months or by the expiration date, as they lose potency
• Patches and spray have longer shelf lives but should still be stored properly

Cost and Availability

Generic Nitroglycerin sublingual tablets cost approximately $15-$50 for 25 tablets. Brand name Nitrostat runs $30-$80. Transdermal patches range from $20-$90 per month depending on generic vs. brand.

Nitroglycerin is generally covered by most insurance plans, including Medicare Part D and Medicaid, as a Tier 1-2 generic. Prior authorization is typically not required.

Due to ongoing supply challenges, finding Nitroglycerin in stock may require checking multiple pharmacies. Use MedFinder to check pharmacy availability near you, and learn how to save money on your prescription.