Patient leaflet - Isomex XL 30 mg prolonged-release tablets

1. What Isomex XL is and what it is used for

Isomex XL contains a medicine called isosorbide mononitrate. This belongs to a group of medicines called nitrates.

It is used to prevent chest pain (angina)
It works by making the blood vessels relax and widen. This makes it easier for the heart to pump blood around the body.

The tablets are made so that they release the medicine slowly over a number of hours.

2. What you need to know before you take Isomex XL

Do not take Isomex XL

If you are allergic to isosorbide mononitrate or any of the other ingredients of this medicine (listed in section 6)
If you have ever had a stroke.
If you have very low blood pressure.
If you have severe anaemia.
If you have a heart problem called ‘cardiomyopathy’ or ‘pericarditis’ or you have narrow heart valves.
If you are taking sildenafil or similar medicines called phosphodiesterase type 5 inhibitors, (used for male impotence). See the section “Other medicines and Isomex XL”.
If you are also taking riociguat. See section “Other medicines and Isomex XL”

Do not take Isomex XL if any of the above apply to you. If you are not sure, talk to your doctor or pharmacist before taking this medicine.

Warnings and precautions

Talk to your doctor or pharmacist before taking Isomex XL if:

You have ever had any serious damage to your heart, such as a heart attack or operation.

If any of the above applies to you, or you are not sure, talk to your doctor or pharmacist before taking Isomex XL.

Other medicines and Isomex XL

Tell your doctor or pharmacist if you are taking, have recently taken or might take any other medicines. This includes medicines that you buy without a prescription and herbal medicines. This is because Isomex XL can affect the way some medicines work and some medicines can have an effect on Isomex XL.

Do not take Isomex XL if you are taking the following medicines:

sildenafil or similar medicines called phosphodiesterase type 5 inhibitors (used for male impotence).

Do not use Isomex XL at the same time as riociguat since this can cause hypotension (abnormally low blood pressure).

Do not take Isomex XL if any of the above apply to you. If you are not sure, talk to your doctor or pharmacist before taking Isomex XL.

Pregnancy, breast-feeding and fertility

If you are pregnant or breast-feeding, think you may be pregnant or are planning to have a baby, ask your doctor or pharmacist for advice before taking this medicine.

Driving and using machines

You may feel dizzy after taking Isomex XL. If this happens, do not drive or use any tools or machines.

Isomex XL contains lactose

Isomex XL contains a type of sugar called lactose. If you have been told by your doctor that you have an intolerance to some sugars, contact your doctor before taking this medicine.

3. How to take Isomex XL

Always take this medicine exactly as your doctor or pharmacist has told you. Check with your doctor or pharmacist if you are not sure.

Taking this medicine

Swallow the tablets whole
Take the tablets with half a glass of water.
Do not crush or chew the tablets.
Take the medicine in the morning.

How much to take

Adults

The recommended dose is two or four tablets a day.
Your doctor may ask you to start on a low dose (one tablet) so that you are less likely to have a reaction to starting Isomex XL.

You must not take Isomex XL for a sudden attack of angina. If you have a sudden attack, take a glyceryl trinitrate tablet (follow the instructions given on the label).

Very occasionally, some people see the remains of the tablet in their bowel motions. This is quite normal and does not mean that the medicine has not been released.

Use in children

Do not give these tablets to children (under 18 years old).

If you take more Isomex XL than you should

If you take more than you should talk to a doctor or go to a hospital straight away. Take the medicine pack with you so the tablets can be identified. The symptoms of an overdose may be pulsing headache, reddening of the skin, cold sweats, nausea, vomiting and a fast heart beat.

If you forget to take Isomex XL

If you forget a dose, take it as soon as you remember it. However, if it is nearly time for the next dose, skip the missed dose. Do not take a double dose to make up for a forgotten dose.

If you have any further questions on the use of this medicine, ask your doctor or pharmacist.

4. Possible side effects

Like all medicines, this medicine can cause side effects, although not everybody gets them.

The following side effects may happen with this medicine:

Headaches.
Feeling sick (nausea).
Feeling dizzy.

The above problems usually disappear with time. Other possible side effects:

Common (may affect up to 1 in 10 people)

Low blood pressure. This may make you feel faint or dizzy.
Faster heartbeat.
Headache
Feeling dizzy.
Feeling sick (nausea)

Uncommon (may affect up to 1 in 100 people)

Being sick (vomiting).
Diarrhoea

Rare (may affect up to 1 in 1,000 people)

Fainting.
Rash.
Itchy skin

Very rare (may affect up to 1 in 10,000 people)

Pain in muscles

Reporting of side effects

If you get any side effects, talk to your doctor, pharmacist or nurse. This includes any possible side effects not listed in this leaflet. You can also report side effects directly via the Yellow Card Scheme. Website: www.mhra.gov.uk/yellowcard or search for MHRA Yellow Card in the Google Play or Apple App Store.

By reporting side effects, you can help provide more information on the safety of this medicine.

5. How to store Isomex XL

Keep this medicine out of the sight and reach of children.

Do not use this medicine after the expiry date which is stated on the carton. The expiry date refers to the last day of that month.

This medicine does not require any special storage conditions.

Do not throw away any medicines via wastewater or household waste. Ask your pharmacist how to throw away medicines you no longer use. These measures will help protect the environment.

6. Contents of the pack and other information

What Isomex XL contains

The active substance in Isomex XL 30 mg prolonged-release tablets is isosorbide mononitrate. Each tablet contains 30 mg of isosorbide mononitrate.

The other ingredients are: hypromellose, lactose monohydrate, pregelatinised starch, magnesium stearate, silica colloidal anhydrous.

What Isomex XL looks like and contents of the pack

Isomex XL are white to off-white, oval tablets.

They are packaged in bottles containing 100 tablets or in blister packs containing 28 or 98 tablets.

Not all pack sizes may be marketed.

Market Authorisation Holder and Manufacturer

Market Authorisation Holder

RPH Pharmaceuticals AB

Box 603

101 32 Stockholm

Sweden

Manufacturer

Astrea Fontaine SAS

Rue de Prés Potets

21121 Fontaine les Dijon

France

This leaflet was last revised in July 2026

If this leaflet is difficult to see or read, or you would like it in a different format, please contact

RPH Pharmaceuticals AB,

Box 603, 101 32,

Stockholm,