Isosorbide mononitrate
HeartAlso known as Imdur
Isosorbide mononitrate is a nitrate that relaxes and widens your blood vessels so blood reaches your heart more easily. Taken every day, it prevents angina (chest pain) episodes. The crucial thing to understand: it works ahead of time, not in the moment. If chest pain hits, you need your fast-acting rescue medicine or emergency help — not this pill.
How to take it
When
Usually once a day in the morning. That timing gives your body a nitrate-free stretch overnight, which keeps the medicine working.
Food
Works with or without food. Swallow extended-release tablets whole — don't crush or chew them.
Avoid
Never combine with erectile dysfunction pills like sildenafil (Viagra) — together they can drop your blood pressure to dangerous, even deadly, levels.
Good to know
Headaches are very common the first week or two and usually fade. Stand up slowly — dizziness is common too.
Missed a dose?
Take it when you remember, unless it's close to your next dose — then skip it. Never double up.
Common side effects
- Headache, especially at first
- Dizziness or lightheadedness when standing
- Flushing
- Nausea
Call a doctor if
- Chest pain that doesn't ease — call emergency services; this pill won't stop an attack in progress
- Fainting or severe lightheadedness — get help now
- A pounding, irregular heartbeat
- Severe headache that won't quit — call your doctor