Isosorbide mononitrate
Isosorbide mononitrate is a nitrate tablet used to prevent angina chest pain in coronary artery disease, listed on PockDose as Imdur in 20mg, 30mg, 40mg and 60mg strengths.
What isosorbide mononitrate is for
Picture someone who gets a tight band of pain across the chest on a hill or a flight of stairs. That is angina: narrowed arteries leave the heart muscle short of oxygen. Isosorbide mononitrate, a nitrate that widens blood vessels, is taken to stop those attacks coming. The body turns it into nitric oxide, vessel walls relax, and the heart has less to push against. It is also used with other medicines in heart failure. It will not stop an attack already under way; that takes a fast-acting nitrate.
How the tablets are taken
Standard isosorbide mononitrate tablets are usually taken two or three times a day. Long-acting tablets such as the Imdur sold here are a single morning dose, swallowed whole. Results build over months, so a fixed routine does better than doses taken as they come to mind. Feeling well is no reason to stop, since coming off suddenly can bring the angina back. Missing the morning tablet and taking it much later in the day shortens the overnight nitrate-free gap that keeps the medicine working.
Headache, dizziness and other effects
Most people get a headache in the first days, and it fades as the body adjusts. Do not skip or move doses to avoid it. Flushing and light-headedness on standing are common too, so get up from a chair or bed slowly. A racing or very slow heartbeat, fainting or blurred vision is less usual. Swelling of the face, lips or tongue, or trouble breathing, needs urgent treatment.
Medicines that clash with nitrates
Do not take sildenafil, tadalafil or vardenafil with isosorbide mononitrate. Together they can drop blood pressure to a dangerous level. Other nitrates, nitroglycerin included, add to the same effect.
The Imdur listing
Here the ingredient is sold as Imdur tablets in 20mg, 30mg, 40mg and 60mg. Every strength holds the same drug; the number only tells you how much nitrate is in each tablet. You will find it in the Heart & Blood Pressure category beside other cardiac medicines. Leave the tablets in their original pack, cool and dry, since heat and damp weaken nitrates over time.
Sources
- Isosorbide: MedlinePlus Drug Information — National Library of Medicine
- Angina – symptoms, diagnosis and treatment - Healthdirect — Healthdirect Australia
Can I order Isosorbide mononitrate online in Hong Kong?
You can order isosorbide mononitrate online with delivery to Hong Kong. The range includes generic Imdur, also sold as Isosorbide tablets, in 20mg, 30mg, 40mg and 60mg tablets. Each order arrives in plain, unbranded packaging with nothing on the outside indicating the contents.
How much does Isosorbide mononitrate cost?
Prices vary between pack sizes. Every product page lists its current prices in HKD or in the currency you choose.
Do I need a prescription to order Isosorbide mononitrate?
PockDose does not ask you to upload a prescription when you order isosorbide mononitrate. See the ordering FAQ for details.
Can I drink alcohol with isosorbide mononitrate?
A small drink is rarely a problem. More than that and blood pressure can fall, so you feel dizzy or faint, most of all when you stand. Get up slowly from a chair or bed after drinking.
Why do I need a nitrate-free period each day?
Nitrates taken around the clock stop working as well, because the body adjusts to them. A gap of several hours with no drug in the system lets the response recover. One long-acting tablet in the morning leaves that gap overnight, which is why the timing of the dose matters as much as the strength.
Can I crush or split an isosorbide mononitrate tablet?
Not the long-acting kind. Swallow it whole with water. Crushing or chewing releases the whole dose at once, which can cause a sharp headache and a sudden drop in blood pressure.
Is isosorbide mononitrate the same as isosorbide dinitrate?
No, they are two medicines. Isosorbide dinitrate is turned into isosorbide mononitrate in the body, so the two act the same way. Most once-daily long-acting nitrate tablets contain the mononitrate, and each has its own strengths and schedule.