Isosorbide mononitrate - oral

Patient Medicine Information
Why do I need this medicine?
Isosorbide mononitrate is used for the prevention and long-term management of angina (chest pain).

This medicine may also be used together with other medicines to treat a certain type of heart failure.
How do I take this medicine?
Take Isosorbide mononitrate exactly as directed by your doctor or according to the instructions on the label. Do not take more or less than instructed by your doctor.

Ask your doctor or pharmacist about whether you should take this medicine with or without food. Different brands of Isosorbide mononitrate may be taken differently.

Try to take it at the same time each day.

This medicine is available as a conventional tablet and an extended-release/prolonged-release tablet or capsule.

If you have been given the extended-release/prolonged-release type of tablet/capsule (usually labelled as “ER”, “LA” or “XL”), swallow it whole with half glass of water. Do not chew or crush the tablets or capsules.

Isosorbide mononitrate must be taken regularly for it to be effective. Continue taking this medicine even when you feel better. Do not stop taking it suddenly as this may worsen your condition.
What should I do if I have forgotten to take this medicine?
Take the missed dose as soon as you remember. If it is almost time for your next dose, skip the missed dose and return to your normal dosing schedule.

DO NOT double a dose under any circumstances.

If you often forget to take your medicine, let your doctor or pharmacist know.
When should I not use this medicine?
Alert your doctor if you have the following conditions:
  • very low blood pressure
  • heart problems
  • conditions that can increase the pressure in the brain e.g. head injury, bleeding in the brain
  • glaucoma (increased pressure in the eye)
  • severe anaemia (low red blood cell count in the body)
  • low blood volume circulating in the body
as Isosorbide mononitrate may not be suitable for you.

Do not take Isosorbide mononitrate with medicines used to treat impotence and certain medicine used to manage high blood pressure in the blood vessels leading to the lungs. Please see the section “Can I take this with other medicines?” below for more information.
What should I take note of while taking this medicine?
Inform your doctor if you have the following conditions:
  • recent history of heart attack
  • underactive thyroid gland
  • low level of oxygen in the blood
  • nutrient imbalance due to an improper or insufficient diet
  • low body temperature
  • severe kidney disease
  • severe liver disease
Isosorbide mononitrate is not intended for the treatment of sudden attacks of chest pain.

Let your doctor know if you are pregnant or breastfeeding.

Keep your appointments with your doctor. Your doctor needs to monitor your condition and check your response to the medication regularly. Your blood pressure may fall to unsafe levels without you noticing it. Monitor your blood pressure and heart rate regularly.
What side effects could I experience?
Isosorbide mononitrate may cause dizziness, blurred vision and tiredness. If affected, do not drive or take part in any activity in which you need to be alert or need to see clearly.

You may experience frequent headaches or dizziness when getting up from a sitting or lying down position, especially if you are taking this medicine for the first time. This is common and should disappear gradually as you get used to Isosorbide mononitrate. It will help if you get up slowly from a sitting or lying position.

Other side effects include any of the following: weakness, flushing, nausea, vomiting, diarrhoea, and increased sweating.

Inform your doctor if any of these side effects do not go away or are severe, or if you experience other side effects.
Can I take this with other medicines?
Do not take Isosorbide mononitrate with the following medicines:
  • medicines used to treat impotence e.g. sildenafil, tadalafil, vardenafil
  • riociguat (medicine used to manage high blood pressure in the blood vessels leading to the lungs)
Inform your doctor and pharmacist if you are taking any of these medicines:
  • medicines for high blood pressure e.g. atenolol, losartan, captopril, amlodipine
  • medicines to treat depression e.g. imipramine, amitriptyline
  • dihydroergotamine (medicine for migraine)
This list does not include all medicines that may interact with Isosorbide mononitrate.

Always notify your doctor or pharmacist if you are taking any other medicines, including herbal tonics such as traditional Chinese medicine, supplements and medicines that you buy without a prescription.
What special dietary instructions should I follow?
Avoid alcohol. Alcohol intake may worsen the dizziness caused by Isosorbide mononitrate.
How should I store this medicine?
Store in a cool, dry place away from the reach of children.

Protect from light and moisture.

Medicines must not be used past the expiry date.
This information is independently developed by MIMS based on isosorbide mononitrate - oral and is provided for your reference only. It is not a replacement for and should only be used in conjunction with full consultation with a licensed healthcare professional, the information provided by your pharmacist and/or the manufacturer of the medication. It may not contain all the available information you require and cannot substitute professional medical care, nor does it take into account all individual circumstances. Although great effort has been made to ensure content accuracy, we shall not be held responsible or liable for any claims or damages arising from the use or misuse of the information contained herein, its contents or omissions, or otherwise. Copyright © 2024 MIMS. All rights reserved. Powered by
  • Cardismo
  • Imdur
  • Isomonit
Register or sign in to continue
Asia's one-stop resource for medical news, clinical reference and education
Already a member? Sign in
Register or sign in to continue
Asia's one-stop resource for medical news, clinical reference and education
Already a member? Sign in