How does isosorbide mononitrate work?
Isosorbide mononitrate relaxes and widens blood vessels, reducing the heart’s workload and helping prevent chest pain.
What is isosorbide mononitrate used to treat?
Isosorbide mononitrate is commonly prescribed for:
- Preventing angina (chest pain)
- Improving blood flow in people with coronary artery disease
Who can take isosorbide mononitrate?
Isosorbide mononitrate is suitable for most adults with heart-related conditions, as prescribed by a doctor.
Who might not be able to take isosorbide mononitrate?
Isosorbide mononitrate may not be suitable if you:
- Have severe low blood pressure (hypotension)
- Have a history of heart attack or stroke
- Have anaemia (low red blood cell count)
- Are taking medications for erectile dysfunction (such as sildenafil, tadalafil, or vardenafil)
Can I take isosorbide mononitrate if I’m pregnant or breastfeeding?
Isosorbide mononitrate isn’t usually recommended during pregnancy or breastfeeding, but your doctor will assess the risks and benefits.
What if I miss a dose?
If you forget a dose, take it as soon as you remember. If it’s close to your next dose, skip the missed one—do not take two doses at once.
How effective is isosorbide mononitrate?
Isosorbide mononitrate is highly effective at preventing angina when taken consistently as prescribed.
What should I do if I take too much?
Taking too much isosorbide mononitrate can cause dangerously low blood pressure, dizziness, or fainting. If you think you’ve taken too much, seek emergency medical help immediately.
What dose of isosorbide mononitrate is usually taken?
- For preventing angina: 20mg to 60mg once or twice daily
- For extended-release tablets: 30mg to 120mg once daily
Your doctor will determine the correct dose based on your condition.
Powered by pharmacies
With over 1,700 pharmacy partners across the UK, you can get the help you need, wherever you are based.
Our website and mobile app make it easy and convenient to manage your health needs and book services at a pharmacy nearby.
What are the side effects of isosorbide mononitrate?
Common side effects include:
- Headache (common in the first few days of treatment)
- Dizziness or lightheadedness
- Flushing (warmth in the face and neck)
- Nausea
Serious side effects, such as severe dizziness, fainting, or allergic reactions, require urgent medical attention.
How should I take isosorbide mononitrate?
Isosorbide mononitrate is taken as tablets (standard or extended-release), usually once or twice daily. Swallow whole with water.
When should isosorbide mononitrate be taken?
Isosorbide mononitrate should be taken at the same time each day, usually in the morning.
What are the brand names for isosorbide mononitrate?
Isosorbide mononitrate is available as a generic medicine, but some branded versions include:
- Imdur
- Monomax
- Ismo
Final thoughts
Isosorbide mononitrate is an effective medication for preventing angina, but it should be taken exactly as prescribed. If side effects occur, speak to your doctor or pharmacist.
