Nitrates: What They Are and How They're Used

Nitrates are a group of medicines commonly used to treat chest pain (angina) and some forms of heart failure. You’ve probably heard of nitroglycerin — that’s a nitrate. Others include isosorbide dinitrate and isosorbide mononitrate. They relax blood vessels, which lowers heart workload and eases chest pain fast.

How nitrates work and common forms

These drugs turn into nitric oxide in your body. That opens up veins and arteries, improving blood flow to the heart. That’s why a small nitroglycerin tablet under the tongue can relieve angina within minutes. Common forms you’ll see are sublingual tablets, sprays, oral pills, patches, and IV in hospitals. Patches and oral pills last longer; sublingual and sprays act fast for sudden pain.

If you get chest pain, use sublingual nitroglycerin right away: place one tablet under the tongue or spray it, wait five minutes. If pain continues, you can take another (follow your doctor’s instructions). If pain does not improve after three doses, call emergency services — that could be a heart attack.

Side effects, interactions, and smart safety tips

Common side effects are headache, lightheadedness, flushing, and low blood pressure. Headaches often mean the drug is working; they may fade over time. Dizziness or fainting are warning signs — sit down when you take nitrates until you know how they affect you.

Big interaction to remember: do NOT take nitrates with PDE5 inhibitors like sildenafil (Viagra), tadalafil (Cialis), or with riociguat. Combining them can cause a dangerous drop in blood pressure. Tell every provider and your pharmacist about nitrates before starting new meds.

Tolerance can develop if you use nitrates all day. Doctors often recommend a daily nitrate-free window (usually overnight) to keep the medicine effective. Don’t stop or change your dose without asking your doctor — they’ll give the right schedule for your situation.

Storage matters: keep sublingual tablets in their original glass bottle, away from heat and moisture. Patches should be applied to clean, dry skin and rotated to avoid irritation. Wash hands after applying topical nitrate to avoid passing it to others.

Watch for signs of overdose or severe reaction: extreme dizziness, fainting, very low blood pressure, or a fast heartbeat. If you suspect overdose or severe side effects, seek emergency care immediately.

Quick checklist: know which nitrate form you use, learn how and when to take it, never mix with erectile dysfunction drugs, expect possible headaches, and keep a nitrate-free period to avoid tolerance. When in doubt, call your doctor — especially if chest pain changes in pattern, becomes more frequent, or won’t respond to your usual dose.

Want specifics about a nitrate you were prescribed? Check the medication leaflet or ask your pharmacist for dosing, side effects, and storage tips tailored to your medicine.