Isosorbide Dinitrate

1 medicine

Isosorbide dinitrate is a nitrate that relaxes blood vessels to prevent and relieve angina. It must never be combined with PDE5 inhibitors such as sildenafil or with riociguat, which can cause a dangerous drop in blood pressure.

Isordil

Isosorbide dinitrate

10mg

Isordil is a heart blood pressure medication containing Isosorbide dinitrate, available as 10mg tablets.

from $0.64 / tablet View

Key facts

  • Isosorbide dinitrate is a long-acting nitrate. It relaxes and widens blood vessels, easing the heart's workload and preventing chest pain from angina.
  • It comes as regular tablets, sustained-release tablets, and a sublingual tablet you dissolve under the tongue for an angina attack already underway.
  • Never take it with sildenafil, tadalafil, vardenafil, avanafil, or riociguat. Combining a nitrate with any of these drugs can drop your blood pressure to dangerous, sometimes fatal, levels.
  • Seek urgent care for severe or fainting-inducing dizziness, chest pain that does not ease with rest and your usual dose, or a fast or irregular heartbeat.

What isosorbide dinitrate treats

Isosorbide dinitrate treats and prevents angina, chest pain caused by reduced blood flow to the heart muscle. Regular dosing schedules prevent attacks, while the sublingual form relieves an attack that has already started. It is also used, alongside other medicines, to ease the workload on the heart in some cases of heart failure.

How isosorbide dinitrate works

The body converts isosorbide dinitrate into nitric oxide, a signal molecule that relaxes the smooth muscle in blood vessel walls. This widens veins and arteries, lowering the pressure the heart pumps against and increasing blood flow to the heart muscle itself. The result is less chest pain and less strain on the heart.

Before you take it

  • Do not take isosorbide dinitrate if you use a PDE5 inhibitor or riociguat, or if you have severe anaemia, very low blood pressure, or increased pressure inside the skull.
  • Tell your prescriber about recent heart attack, aortic stenosis, hypertrophic cardiomyopathy, or glaucoma, since nitrates can affect these conditions.
  • Alcohol adds to the blood-pressure-lowering effect and can worsen dizziness.
  • Stand up slowly, especially when starting treatment or increasing the dose, since a sudden drop in blood pressure on standing is common.

Side effects

Common effects include headache (often most noticeable in the first days of treatment), flushing, dizziness, and a fast heartbeat.

Stop and seek urgent medical care for any of these:

  • Fainting or severe lightheadedness.
  • Chest pain that does not respond to rest and your usual dose.
  • A fast or irregular heartbeat.
  • Signs of a severe allergic reaction, such as facial swelling or difficulty breathing.

Safety essentials

  • Never combine isosorbide dinitrate with sildenafil, tadalafil, vardenafil, avanafil, or riociguat. The combination can cause a severe, dangerous drop in blood pressure. If you take a nitrate and develop chest pain during sex, tell emergency staff you have taken it.
  • Your dosing schedule should include a nitrate-free interval each day, usually overnight. Continuous round-the-clock use lets the body build tolerance, so the medicine stops working as well.
  • Do not stop long-term nitrate treatment abruptly. Stopping suddenly can trigger a rebound worsening of angina; any change in dose should be planned with your prescriber.
  • If sublingual tablets do not relieve an attack within the expected time, or pain is severe, seek emergency care rather than repeating doses on your own.

This page is educational and does not replace advice from a doctor or pharmacist who knows your health history.