The text above reproduces the patient information leaflet approved for this medicine, restructured for easier reading.Source: electronic medicines compendium (emc), DatapharmActive substance: isosorbide dinitrateOfficial document: view the original leaflet on emc →Medical disclaimer: This page is for information only and does not replace advice from your doctor or pharmacist. Always read the leaflet supplied with your medicine. If you are unwell, call NHS 111; in an emergency, call 999.

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Isoket Retard 40mg Tablets

⚠ This medicine appears to have been discontinued

The electronic medicines compendium (emc) no longer publishes a Summary of Product Characteristics for this product, which usually means it is no longer marketed in the UK. The patient leaflet below is kept for reference, but the product may not be available.

If you were prescribed this medicine, other products containing Isosorbide dinitrate may still be available. Do not stop your treatment — ask your pharmacist or GP what to use instead.

Active substance: Isosorbide dinitrate

Source: electronic medicines compendium (emc)

Official leaflet: Read the PIL on emc

What it is and what it is used for

for Isoket Retard belongs to a group of medicines called organic nitrates. Organic nitrates work by widening the blood vessels in your heart to allow an increased amount of blood to flow to areas which need it. Isoket Retard is used to prevent and treat angina pectoris. Angina usually feels like a tight pain in the chest, neck or arm area. The pain comes from the heart muscle and is a sign that part of it is not getting enough oxygen for the amount of work it is doing.

What you need to know before you take it

e Isoket Retard Do not take Isoket Retard if:  You are allergic to isosorbide dinitrate, other nitrates or any of the other ingredients of this medicine (listed in section 6)  You suffer from anaemia (reduction in red blood cells which can make the skin pale and cause weakness or breathlessness)  You have had a heart attack (myocardial infarction)  You have had a brain haemorrhage (bleeding)  You have had a head injury (trauma)  You have a low blood volume (hypovolaemia)  You have very low blood pressure  Your blood has stopped circulating around your body properly (circulatory failure).  You take sildenafil ("Viagra") or any other phosphodiesterase inhibitor.  You take products that contain riociguat, a medicine used in treating pulmonary hypertension.

Warnings and precautions  Talk to your doctor or pharmacist before taking Isoket Retard if:You have hypothyroidism (an underactive thyroid gland which can cause tiredness or weight gain)  You are malnourished (severely underfed)  You have liver or kidney disease  You suffer from hypothermia (a very low body temperature)  You suffer from very poor circulation  You have been diagnosed with any of the following heart conditions: hypertrophic obstructive cardiomyopathy (HOCM), constrictive pericarditis, cardiac tamponade, low cardiac filling pressures, aortic/mitral valve stenosis and diseases associated with raised intra-cranial (head) pressure.  You have an abnormally low level of oxygen in the blood and impaired gas exchange due to lung disease or ischaemic heart disease 

      

Other medicines and Isoket RetardDo not take Isoket Retard with phosphodiesterase inhibitors such as Sildenafil ("Viagra"), used for impotence. Using Isoket Retard with these medicines could cause your blood pressure to fall to a dangerously low level. You must not stop taking Isoket Retard to take Sildenafil as this will increase your chances of having an angina attack. Do not take Isoket Retard with products that contain riociguat.

Tell your doctor or pharmacist if you are taking, have recently taken or might take any other medicines, including:Medicines to lower your blood pressure. Monoamine oxidase inhibitors (used to treat depression) Tricyclic antidepressants (used to treat depression) and neuroleptics (used to treat anxiety). Ergotamine used for migraine. Sapropterin used for phenylketonuria (PKU). Any other medicine, including medicines obtained without a prescription.

Isoket with alcohol Do not drink alcohol. It could increase the effect of Isoket and lower your blood pressure too much. If this happens, you may feel dizzy or faint. Pregnancy and breast-feeding 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 Isoket may give you a headache, or make you feel dizzy or tired. If this happens to you, do not drive or operate machinery. Isoket Retard contains lactose If you have been told by your doctor that you have an intolerance to some sugars, contact your doctor before taking this medicinal product.

How to take it

Isoket Retard Always take this medicine exactly as your doctor or pharmacist has told you. Check with your doctor or pharmacist if you are not sure. Important: Your doctor will choose the dose that is right for you. Your dose will be shown clearly on the label that your pharmacist puts on your medicine. If it does not, or you are not sure, ask your doctor or pharmacist. Remember: You should not chew the tablets, swallow them whole with a glass of water. Adults  The usual dose is one or two tablets per day. If you are taking two tablets, it is important to take the second tablet six to eight hours after the first. Taking the tablets in this way allows a period of time (when you are sleeping) when no tablets are taken. This is called a "nitrate low" period and is needed to make sure your medicine remains effective. Use in children This medicine is not suitable for children.

If you take more Isoket Retard than you should Do not take more Isoket Retard than you should. If you accidentally take too much, immediately contact the nearest hospital casualty department or your doctor. Too much Isoket Retard may cause your blood pressure to fall too low, making you feel sick, faint and dizzy. A very large overdose could cause a coma or collapse and require immediate resuscitation. If you forget to take Isoket Retard Do not take a double dose to make up for a forgotten dose. Take your next dose at the usual time. If you stop taking Isoket Retard Do not stop taking Isoket Retard without first talking to your doctor. You should keep taking your medicine until your doctor tells you to stop. Do not stop taking it just because you feel better. If you stop taking the tablets your condition may get worse. If you have any further questions about the use of this medicine, ask your doctor or pharmacist.

Possible side effects

Like all medicines this medicine can cause side effects, although not everybody gets them. Stop taking this medicine and seek immediate medical help if you have any of the following symptoms:  Swelling of the face or throat, causing difficulty in breathing or wheezing  Fainting or collapse  Swelling or blistering of the skin, mouth, eyes and genitals (Stevens-Johnson syndrome). Speak to your doctor or pharmacist if you have any of the following symptoms:

Very common (may affectmore than 1 in 10 people):  Mild headaches at the start of treatment. Usually they disappear after a few days. Common (may affect up to 1 in 10 people):  Dizziness  Tiredness  Feeling weak  Fast heartbeat They may occur for the first few days of treatment or after your dosage has been increased. Uncommon (may affect up to 1 in 100 people):  Feeling sick or being sick  Skin rashes or flushing  Looking pale  Excessive sweating  Restlessness  Worse angina. Very rare (may affect up to 1 in 10,000 people)  Heartburn  Red or scaly skin (exfoliative dermatitis) Reporting of side effects If you get any side effects, talk to your doctor or pharmacist. This includes any possible side effects not listed in this leaflet. You can also report side effects directly via Yellow Card Scheme at: 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.

How to store it

Isoket Retard 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 medicines will help protect the environment.

Contents of the pack and other information

What Isoket Retard contains The active substance is isosorbide dinitrate 40 mg.

The other ingredients are lactose monohydrate, talc, polyvinyl acetate, magnesium stearate and potato starch. What Isoket Retard looks like Isoket Retard is a white tablet marked with IR/40 on the front and SCHWARZ PHARMA on the back. They come in blister packs of 50, 56, 60, 84 and 90 tablets. Not all pack sizes may be marketed. Marketing Authorisation Holder Norgine Pharmaceuticals Limited ARC Uxbridge, Building 01, Sanderson Road, Uxbridge, UB8 1DH, UK Manufacturer Aesica Pharmaceuticals GmbH, Alfred Nobel Strasse 10, D-40789, Monheim, Germany This leaflet was last revised in March 2025 If this leaflet is difficult to see or read or you would like it in a different format, please contact Norgine Pharmaceuticals Limited ARC Uxbridge, Building 01, Sanderson Road, Uxbridge, UB8 1DH, UK

Frequently asked questions about Isoket Retard 40mg Tablets

How do I take Isoket Retard 40mg Tablets?

Isoket Retard 40mg Tablets comes as tablet containing 40mg. Always follow the dose your doctor or pharmacist has given you, and read the leaflet that comes with the medicine.

What is the active substance in Isoket Retard 40mg Tablets?

The active substance in Isoket Retard 40mg Tablets is isosorbide dinitrate.

Where does this information come from?

This leaflet reproduces the patient information leaflet approved for Isoket Retard 40mg Tablets, as published on the electronic medicines compendium (emc). The version printed inside your medicine’s packaging is the one that applies to you.

Can I get Isoket Retard 40mg Tablets without a prescription?

Whether a medicine is available over the counter or on prescription only depends on its licence. Check the leaflet, or ask your pharmacist — they can tell you straight away.

About this leaflet

The text above reproduces the patient information leaflet approved for this medicine, restructured for easier reading.

Source: electronic medicines compendium (emc), Datapharm
Active substance: isosorbide dinitrate
Official document: view the original leaflet on emc →

Medical disclaimer: This page is for information only and does not replace advice from your doctor or pharmacist. Always read the leaflet supplied with your medicine. If you are unwell, call NHS 111; in an emergency, call 999.

Medicines with the same active substance: Isosorbide dinitrate (7 medicines)

See every medicine containing this substance, or browse the full A–Z of active substances.

⚕For healthcare professionals — Summary of Product Characteristics (SmPC)Full SmPC: dosage, interactions, contraindications, warnings+

Technical information intended for healthcare professionals (doctors and pharmacists). The Summary of Product Characteristics (SmPC) is the official document approved by the MHRA/EMA. It does not replace the patient leaflet or a doctor’s advice.

4.1. Therapeutic indications

For the prophylaxis and treatment of angina pectoris.

4.2. Posology and method of administration

Posology

Adults: One tablet to be taken once daily without chewing and with a sufficient amount of fluid. For patients with higher nitrate requirements the dose may be increased to one tablet twice daily; but ensuring a 10 - 12 hours treatment free interval every 24 hours.

Elderly population: Clinical experience has not necessitated alternative advice for use in elderly patients.

Paediatric population: The safety and efficacy of Isoket Retard has yet to be established.

Method of administration

For oral administration

4.3. Contraindications

Hypersensitivity to the active substance or to any of the excipients listed in section 6.1.

This product should not be given to patients with a known sensitivity to nitrates, very low blood pressure, acute myocardial infarction with low filling pressure, marked anaemia, head trauma, cerebral haemorrhage, acute circulatory failure, severe hypotension or hypovolaemia.

Phosphodiesterase inhibitors (e.g. Sildenafil) have been shown to potentiate the hypotensive effects of nitrates, and their co-administration with nitrates or nitric oxide donors is therefore contraindicated.

During nitrate therapy, the soluble guanylate cyclase stimulator riociguat must not be used (see section 4.5).

4.4. Special warnings and precautions for use

These tablets should be used with caution in patients who are suffering from hypothyroidism, hypothermia, malnutrition, severe liver disease or renal disease.

Symptoms of circulatory collapse may arise after the first dose, particularly in patients with labile circulation.

This product may give rise to symptoms of postural hypotension and syncope in some patients.

These tablets should be used with particular caution and under medical supervision in the following:

Hypertrophic obstructive cardiomyopathy (HOCM), constrictive pericarditis, cardiac tamponade, low cardiac filling pressures, aortic/mitral valve stenosis, and diseases associated with raised intracranial pressure.

Treatment with these tablets must not be interrupted or stopped to take phosphodiestearase inhibitors due to the increased risk of inducing an attack of angina pectoris.

If these tablets are not taken as indicated with the appropriate dosing interval (see section 4.2) tolerance to the medication could develop.

Hypoxaemia

Caution should be exercised in patients with hypoxaemia and ventilation/perfusion imbalance due to lung disease or ischaemic heart failure. As a potent vasodilator, ISDN could result in increased perfusion of poorly ventilated areas, worsening of the ventilation/perfusion imbalance, and a further decrease in the arterial partial pressure of oxygen.

During treatment with ISDN alcohol should be avoided as it may potentiate the hypotensive and vasodilating effect of ISDN (see section 4.5).

Patients with rare hereditary problems of galactose intolerance, total lactase deficiency or glucose-galactose malabsorption should not take this medicine.

4.5. Interaction with other medicinal products and other forms of interaction

Concurrent intake of drugs with blood pressure lowering properties e.g. beta blockers, calcium antagonists, vasodilators, ACE-inhibitors, monoamine oxidase inhibitors etc. and/or alcohol may potentiate the hypotensive effect of the tablets. Symptoms of circulatory collapse can arise in patients already taking ACE inhibitors.

The concurrent intake of ISDN with ACE-inhibitors or arterial vasodilators could be a desirable interaction unless the antihypertensive effects are excessive in which case consider reducing the dose of one or both drugs.

The hypotensive effect of nitrates is potentiated by concurrent administration of phosphodiesterase inhibitors (e.g. sildenafil). This might also occur with neuroleptics and tricyclic antidepressants.

Reports suggest that when administered concomitantly, nitrates may increase the blood level of dihydroergotamine and its hypertensive effect.

Saproterin (Tetrahydrobioterine, BH4) is a cofactor for nitric oxide synthetase. Caution is recommended during concomitant use of saproterin-containing medicine with all agents that cause vasodilation by affecting nitric oxide (NO) metabolism or action, including classical NO donors (e.g. glyceryl trinitrate (GTN), isosorbide dinitrate (ISDN), isosorbide mononitrate (ISMN) and others).

The use of isosorbide dinitrate with riociguat, a soluble guanylate cyclase stimulator, is contraindicated (see section 4.3) since concomitant use can cause hypotension.

4.6. Fertility, pregnancy and lactation

Pregnancy and lactation

This product should not be used during pregnancy or lactation unless considered essential by the physician.

Fertility

There is no data available on the effect of ISDN on fertility in humans.

4.7. Effects on ability to drive and use machines

Headaches, tiredness and dizziness may occur. These may affect the ability to drive and operate machinery. Patients should not drive or operate machinery if their ability is impaired.

4.8. Undesirable effects

Undesirable effects frequencies are defined as: very common (≥1/10), common (≥1/100,<1/10), uncommon (≥1/1,000,<1/100), rare ≥1/10,000,<1/1,000), very rare (<1/10,000), not known (cannot be estimated from the available data).

During administration of Isoket the following undesirable effects may be observed:

Nervous system disorders:

Very common: headache

Common: dizziness, somnolence

Cardiac disorders:

Common: tachycardia

Uncommon: angina pectoris aggravated

Vascular disorders:

Common: orthostatic hypotension

Uncommon: circulatory collapse (sometimes accompanied by bradyarrhythmia and syncope)

Not known: hypotension

Gastrointestinal disorders:

Uncommon: nausea, vomiting

Very rare: heartburn

Skin and subcutaneous tissue disorders:

Uncommon: allergic skin reaction (e.g. rash), flushing

Very rare: angioedema, Stevens-Johnson- Syndrome

Not known: exfoliative dermatitis

General disorders and administration site conditions:

Common: asthenia

Severe hypotensive responses have been reported for organic nitrates and include nausea, vomiting, restlessness, pallor and excessive perspiration.

During treatment with these tablets, a temporary hypoxaemia may occur due to a relative redistribution of the blood flow in hypoventilated alveolar areas. Particularly in patients with coronary artery disease this may lead to a myocardial hypoxia.

Reporting of suspected adverse reactions

Reporting suspected adverse reactions after authorisation of the medicinal product is important. It allows continued monitoring of the benefit/risk balance of the medicinal product. Healthcare professionals are asked to report any suspected adverse reactions via the Yellow Card Scheme, www.mhra.gov.uk/yellowcard or search for MHRA Yellow Card in the Google Play or Apple App Store.

4.9. Overdose

Symptoms:

• Fall of blood pressure ≤ 90mm Hg, paleness, sweating, weak pulse, tachycardia, light-headedness on standing, headache, weakness, dizziness, nausea and vomiting

• During isosorbide mononitrate biotransformation nitrite ions are released, which may include methaemoglobinaemia and cyanosis with subsequent tachypnoea, anxiety, loss of consciousness and cardiac arrest. It cannot be excluded that an overdose of isosorbide dinitrate may cause this adverse reaction.

• In very high doses the intracranial pressure may be increased. This might lead to cerebral symptoms.

Supportive measures

• Stop intake of the drug

• General procedures in the event of nitrate-related hypotension:

Patient should be kept horizontal with the head lowered and legs raised

Supply oxygen

Expand plasma volume

For specific shock treatment admit patient to intensive care unit

Specific Procedures

• Raising the blood pressure if the blood pressure is very low

• Treatment of methaeglobinaemia

Reduction therapy of choice with vitamin C, methylene-blue, or toluidine-blue

Administer oxygen (if necessary)

Initiate artificial ventilation

Hemodialysis (of necessary)

• Resuscitation measures:

In case of signs of respiratory and circulatory arrest, initiate resuscitation measures immediately.

💬 Ask about this leaflet

Ask anything about Isoket Retard 40mg Tablets. The assistant answers only from this leaflet — if the leaflet does not cover it, it will say so. It does not give medical advice.

Answers come from the patient leaflet published on the electronic medicines compendium (emc). They are not medical advice. Ask a pharmacist or your GP if you are unsure. For urgent help call NHS 111, or 999 in an emergency.

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