Consumer medicine information

Isordil Sublingual Tablets

Isosorbide dinitrate

BRAND INFORMATION

Brand name

Isordil

Active ingredient

Isosorbide dinitrate

Schedule

S3

 

Consumer medicine information (CMI) leaflet

Please read this leaflet carefully before you start using Isordil Sublingual Tablets.

SUMMARY CMI

Isordil Sublingual tablets

Consumer Medicine Information (CMI) summary

The full CMI on the next page has more details. If you are worried about using this medicine, speak to your doctor or pharmacist.

1. Why am I using Isordil?

Isordil Sublingual tablets contains the active ingredient isosorbide dinitrate. Isordil is used to treat and prevent angina attacks.

For more information, see Section 1. Why am I using Isordil? in the full CMI.

2. What should I know before I use Isordil?

Do not use if you have ever had an allergic reaction to Isordil or any of the ingredients listed at the end of the CMI.

Talk to your doctor if you have any other medical conditions, take any other medicines, or are pregnant or plan to become pregnant or are breastfeeding.

For more information, see Section 2. What should I know before I use Isordil? in the full CMI.

3. What if I am taking other medicines?

Some medicines may interfere with Isordil and affect how it works.

A list of these medicines is in Section 3. What if I am taking other medicines? in the full CMI.

4. How do I use Isordil?

  • Place 1 or 2 tablets under tongue at first signs of an anginal attack
  • If angina not relieved call doctor or nearest hospital immediately

More instructions can be found in Section 4. How do I use Isordil? in the full CMI.

5. What should I know while using Isordil?

Things you should do
  • Remind any doctor, dentist or pharmacist you visit that you are using Isordil.
  • Visit doctor regularly and tell your doctor if angina attacks are getting worse or more frequent
Things you should not do
  • Chew or crush tablet.
  • If you have been taking Isordil regularly for some time, do not stop taking suddenly
Driving or using machines
  • Be careful until you know how Isordil affects you.
Drinking alcohol
  • May increase dizziness or faintness
Looking after your medicine
  • Store below 30°C in a cool dry place

For more information, see Section 5. What should I know while using Isodil? in the full CMI.

6. Are there any side effects?

More common side effects are: headache, dizziness light headedness or feeling faint. Serious side effects; severe drops in blood pressure and increased heart rate.

For more information, including what to do if you have any side effects, see Section 6. Are there any side effects? in the full CMI.



FULL CMI

Isordil Sublingual tablets

Active ingredient(s): Isosorbide dinitrate

Consumer Medicine Information (CMI)

This leaflet provides important information about using Isordil Sublingual tablets. You should also speak to your doctor or pharmacist if you would like further information or if you have any concerns or questions about using Isordil.

Where to find information in this leaflet:

1. Why am I using Isordil?
2. What should I know before I use Isordil?
3. What if I am taking other medicines?
4. How do I use Isordil?
5. What should I know while using Isordil?
6. Are there any side effects?
7. Product details

1. Why am I using Isordil?

Isordil contains the active ingredient isosorbide dinitrate. Isordil is part of a group of medicines called nitrates and works by opening up blood vessels which allows more blood and oxygen to reach the heart.

Isordil is used to treat and prevent angina attacks.

Isordil may also be helpful in the treatment of some types of heart failure.

2. What should I know before I use Isordil?

Warnings

Do not use Isordil if:

  • you are allergic to isosorbide dinitrate, or any of the ingredients listed at the end of this leaflet, or any medication or food containing nitrates or nitrites.
    Symptoms of an allergic reaction may include skin rash, itching or hives on the skin, swelling of the face, lips, tongue or other parts of the body, shortness of breath, wheezing or troubled breathing, hay fever, and feeling faint.
  • You have any of the following conditions.
    - certain types of heart or vascular disease
    - very low blood pressure
    - anaemia
    - pregnant or breast feeding, unless advised otherwise by your doctor
  • Always check the ingredients to make sure you can use this medicine.
  • You are a child. Isordil is not recommended for use in children

Check with your doctor if you:

  • have any other medical conditions
    - heart, liver or kidney disease
    - blood disorders or hardening of the arteries
    - low blood pressure
    - if you have recently had a heart attack, stroke or head injury
    - hypothyroidism, hypothermia, malnutrition or angle closure glaucoma
    - other medical conditions
  • take any medicines for any other condition

During treatment, you may be at risk of developing certain side effects. It is important you understand these risks and how to monitor for them. See additional information under Section 6. Are there any side effects?

Pregnancy and breastfeeding

Do not use Isordil if pregnant or breast feeding unless your doctor has advised you can

Check with your doctor if you are pregnant or intend to become pregnant.

3. What if I am taking other medicines?

Tell your doctor or pharmacist if you are taking any other medicines, including any medicines, vitamins or supplements that you buy without a prescription from your pharmacy, supermarket or health food shop.

Some medicines may interfere with Isordil and affect how it works.

These include

  • medications for high blood pressure and other heart medications
  • tranquillisers/sedatives
  • medications for arthritis
  • medications for depression

These medicines may affect the way Isordil works.

Your doctor or pharmacist can tell you what to do if you are taking any of these medicines.

Do not start to take any other medicine unless prescribed or approved by your doctor.

Check with your doctor or pharmacist if you are not sure about what medicines, vitamins or supplements you are taking and if these affect Isordil.

4. How do I use Isordil?

How much to take / use

  • At the first signs of an anginal attack, place one or two tablets under your tongue. If your angina is not relieved after taking these tablets you should call your doctor or nearest hospital immediately.

Your may doctor may recommend a different dose for you. Elderly patients may need a lower dose

  • Heart failure: follow your doctors instructions for the recommended dosage

When to take / use Isordil

  • Isordil should be used at the first sign of angina attack

If you forget to use Isordil

Isordil when prescribed for treatment of angina is not taken at a set time each day.

For other heart failure conditions is may be prescribed to be taken at a regular time

If it is almost time for your next dose, skip the dose you missed and take your next dose when you are meant to.

Do not take a double dose to make up for the dose you missed.

If you use too much Isordil

If you think that you have used too much Isordil, you may need urgent medical attention.

If you take too many Isordil tablets, you may experience a headache, become flushed, experience cold sweats, nausea, vomiting, very low blood pressure and a fast heartbeat

You should immediately:

  • phone the Poisons Information Centre
    (by calling 13 11 26), or
  • contact your doctor, or
  • go to the Emergency Department at your nearest hospital.

You should do this even if there are no signs of discomfort or poisoning.

5. What should I know while using Isordil?

Things you should do

Visit your doctor regularly for a check up and always discuss with your doctor any problems you have with Isordil tablets.

Tell your doctor immediately if your angina attacks are getting worse or more frequent whilst using Isordil.

Take Isordil as your doctor has prescribed.

Keep enough tablets to last weekends and holidays.

If you do happen to run out, Isordil can be purchased from a pharmacy without a prescription.

Before having any type of surgery, tell your doctor or anaesthetist you are taking Isordil.

If a headache occurs after taking Isordil, pain relievers are recommended. The headache usually disappears on continual therapy with Isordil. If the headache persists, contact your doctor.

Call your doctor straight away if your:

  • angina is not relieved after taking these tablets you should call your doctor or nearest hospital immediately.

Remind any doctor, dentist or pharmacist you visit that you are using Isordil.

Things you should not do

  • If you have been taking Isordil regularly for some time, do not suddenly stop taking it as this may bring on an angina attack.
  • Check with your doctor for the best way to slowly reduce the amount of Isordil you are taking before stopping completely.
  • Crush or chew the tablets.
  • Do not give this medicine to anyone else.
  • Do not take any other medicines unless you have discussed this with your doctor or pharmacist.
    This includes medicines you can buy without a prescription from a pharmacy, supermarket or health food shop.

Things to be careful of

  • Get up slowly when getting out of bed or standing up from a sitting position if you feel light-headed, dizzy or faint. You may feel light-headed or dizzy or faint when you begin to take Isordil. This is because your blood pressure is falling suddenly. Standing up slowly, especially when you get up from bed or chairs, will help your body get used to the change in position and blood pressure. The problem usually goes away after the first few doses
  • Even though you may feel better when you start taking Isordil, be careful to avoid excessive physical activities.

Driving or using machines

Be careful before you drive or use any machines or tools until you know how Isordil affects you.

Drinking alcohol

Tell your doctor if you drink alcohol.

Alcohol may cause any dizziness or faintness to be worse.

Looking after your medicine

  • Store below 30°C.

Follow the instructions in the carton on how to take care of your medicine properly.

Keep your Isordil tablets in the bottle until it is time to take them.

If you take the tablets out of the bottle they will not keep well.

Store it in a cool dry place away from moisture, heat or sunlight; for example, do not store it:

  • in the bathroom or near a sink, or
  • in the car or on window sills.

Keep it where young children cannot reach it.

Getting rid of any unwanted medicine

If you no longer need to use this medicine or it is out of date, take it to any pharmacy for safe disposal.

Do not use this medicine after the expiry date.

6. Are there any side effects?

Isordil helps most people with angina, but it may have unwanted side effects in some people.

All medicines can have side effects. If you do experience any side effects, most of them are minor and temporary. However, some side effects may need medical attention.

See the information below and, if you need to, ask your doctor or pharmacist if you have any further questions about side effects.

Less serious side effects

Less serious side effectsWhat to do
  • headache (temporary or persistent)
  • dizziness, light-headedness, or feeling faint, especially when getting up from sitting or lying down
Less common
  • flushing
  • swollen hands and feet
  • skin rash and flaking of the skin
  • anaemia
  • increase in your heart rate
  • hypoxaemia (low blood oxygen levels)
Speak to your doctor if you have any of these less serious side effects and they worry you.

Serious side effects

Serious side effectsWhat to do
Cardiovascular
  • severe drops in blood pressure and an increase in your heart rate
  • sensitive patients may experience a decrease in blood flow, which could damage your heart or result in heart failure.
Call your doctor straight away, or go straight to the Emergency Department at your nearest hospital if you notice any of these serious side effects.

Tell your doctor or pharmacist if you notice anything else that may be making you feel unwell.

Other side effects not listed here may occur in some people.

Reporting side effects

After you have received medical advice for any side effects you experience, you can report side effects to the Therapeutic Goods Administration online at www.tga.gov.au/reporting-problems. By reporting side effects, you can help provide more information on the safety of this medicine.

Always make sure you speak to your doctor or pharmacist before you decide to stop taking any of your medicines.

7. Product details

This medicine is only available with a doctor's prescription.

What Isordil contains

Active ingredient
(main ingredient)		Each tablet contains 5 mg isosorbide dinitrate
Other ingredients
(inactive ingredients)
  • lactose monohydrate
  • starch
  • magnesium stearate
  • microcrystalline cellulose
  • Erythrosine Lake CI 45430 colouring agent
Potential allergensContains sugars as lactose

Do not take this medicine if you are allergic to any of these ingredients.

What Isordil Sublingual tablets looks like

Isordil 5mg Sublingual tablets are pink round tablets, supplied in a bottle containing 100 tablets … (Aust R 12957).

Who distributes Isordil Sublingual tablets

Arrotex Pharmaceuticals Pty Ltd
15-17 Chapel Street
Cremorne VIC 3121
www.arrotex.com.au

This leaflet was prepared in February 2025

Published by MIMS April 2025

BRAND INFORMATION

Brand name

Isordil

Active ingredient

Isosorbide dinitrate

Schedule

S3

 

1 Name of Medicine

Isosorbide dinitrate.

2 Qualitative and Quantitative Composition

Isordil sublingual tablets contain 5 mg of isosorbide dinitrate.
Isordil oral tablets come in three strengths and contain 10 mg, 30 mg or 40 mg of isosorbide dinitrate.

Excipients with known effect.

Sugars as lactose.
For the full list of excipients, see Section 6.1 List of Excipients.

3 Pharmaceutical Form

Isordil sublingual tablets.

5 mg.

Round, flat, pink, unmarked tablet.

Isordil oral tablets.

10 mg*.

Round, white, bi-convex tablet impressed with the company logo with a break bar on other side.

30 mg*.

Round, blue, bi-convex tablet, impressed with the company logo and a break bar on other side.

40 mg*.

Round, green, bi-convex tablet, impressed with the company logo and a break bar on other side.
* Currently not marketed.

4 Clinical Particulars

4.1 Therapeutic Indications

Treatment of angina pectoris (classic effort associated angina, chronic stable angina, vasospastic angina, variant angina, unstable angina and angina decubitus) and myocardial ischaemia due to ischaemic heart disease, and an aid in the management of left ventricular failure, either alone or as part of the syndrome of congestive heart failure.

Sublingual.

Prevention and treatment of angina pectoris and myocardial ischaemia due to ischaemic heart disease. Acute and chronic left ventricular failure, either alone or as part of the syndrome of congestive heart failure, to improve cardiac performance and stabilise the patient's condition.

Oral.

Relief of angina pectoris. It is not intended to abort the acute anginal episode, but is useful in the prophylactic treatment of angina pectoris and myocardial ischaemia due to ischaemic heart disease. An aid in the management of left ventricular failure, either alone or as part of the syndrome of congestive heart failure.

4.2 Dose and Method of Administration

Tolerance to the antianginal effects (measured by exercise stress testing) and effects in heart failure of nitrates has been shown to be a major factor limiting efficacy and blunting the effect of sublingual nitroglycerin when nitrates are used either continuously (i.e. infusion, transdermal) or with any regular schedule of oral administration where dosing occurs every 8 hours or more often during a day. The development of tolerance can be altered (prevented or attenuated) by a noncontinuous (intermittent or asymmetric) dosing schedule. In general, a nitrate free interval of at least 8 hours every 24 hours is recommended to prevent tolerance.

Adult.

Angina pectoris and myocardial ischaemia due to ischaemic heart disease. The usual dose of sublingual isosorbide dinitrate for this indication is 5 to 10 mg every two to three hours, for treatment of an angina pectoris attack, or prophylactically in situations likely to provoke such attacks. The sublingual tablets may also be swallowed in doses of 5 to 10 mg for prevention of angina pectoris or to supplement the oral dosage form.
Oral tablets should be taken in doses of 5 to 30 mg four times daily, the average patient requiring 10 mg four times daily.
Left ventricular failure either alone or as part of the syndrome of congestive heart failure. In order to obtain full therapeutic effect, it is important that the dosage of sublingual and oral forms be individualised in accordance with each patient's needs, clinical response and haemodynamic monitoring. Isordil therapy should begin with the lowest effective dose and further adjusted as necessary, based on left ventricular performance. For treatment of acute left ventricular failure, the sublingual form of Isordil should be preferred. For the treatment of chronic left ventricular failure, initially the rapid acting sublingual form of Isordil should be administered to stabilise the patient's symptoms or to determine the magnitude of haemodynamic response; then it should be followed by the oral form for maintenance therapy.
The average recommended doses for acute and chronic left ventricular failure are the following:

Acute left ventricular failure.

Sublingual tablet: 5 to 10 mg every two hours or as needed.

Chronic left ventricular failure.

Initial dosage, sublingual tablet: 5 to 10 mg every two hours or as needed. Maintenance dosage, oral tablet: 20 to 40 mg four times daily or as needed.

4.3 Contraindications

In patients with a confirmed diagnosis of isolated right ventricular failure, particularly in the setting of acute myocardial infarction and due to dominant right ventricular infarction.
Known hypersensitivity to isosorbide dinitrate or a known idiosyncratic reaction to organic nitrate drugs.
Hypotension or uncorrected hypovolaemia, as the use of isosorbide dinitrate in such states could produce severe hypotension or shock.
Constrictive pericarditis and pericardial tamponade.
Severe anaemia or arterial hypoxaemia.
Intracranial hypertension.
Do not use isosorbide dinitrate in patients who are taking certain drugs for erectile dysfunction (phosphodiesterase inhibitors), such as sildenafil, tadalafil or vardenafil. Concomitant use can cause severe hypotension, syncope or myocardial ischemia.
Acute circulatory failure (shock, vascular collapse).
Aortic/mitral valve stenosis and disease associated with a raised intra-cranial pressure e.g. following a head trauma and including cerebral haemorrhage.

4.4 Special Warnings and Precautions for Use

As with other vasodilators, Isordil may cause paradoxical side effects in sensitive patients, which may increase ischaemia and may even lead to extension of myocardial damage and advanced congestive heart failure.

Acute myocardial infarction.

Data supporting the use of nitrates during the acute phase of myocardial infarction (the period during which clinical and laboratory findings are unstable) are insufficient to establish safety. Management of acute left ventricular failure secondary to acute myocardial infarction depends on accurate diagnosis, and may require flow directed cardiac catheterisation before institution of appropriate drug therapy.

Hypotension.

Care must be taken to avoid the significant risk of a precipitous fall in blood pressure, particularly in patients with severe coronary or cerebral atherosclerosis or renal insufficiency. Isosorbide dinitrate may cause faintness if taken while standing or sitting, and this hazard is of particular importance in patients not previously treated with the drug.

Withdrawal.

Nitrate dependence is a potentially serious problem. In terminating treatment of patients with angina who are receiving isosorbide dinitrate, both the dosage and frequency of administration should be gradually reduced over a period of two weeks to prevent potential withdrawal reactions such as increased frequency of angina attacks.

Tolerance.

During sustained therapy with isosorbide dinitrate, partial tolerance to the antianginal and circulatory effects may develop. Cross tolerance to other organic nitrates or nitrites may occur.
In the treatment of acute or chronic cardiac failure, pulmonary capillary pressure should not be allowed to fall below 15 mmHg or systolic blood pressure below the physiological range in normal or hypertensive patients. Systolic pressure should be preserved in patients with pre-existing hypotension in the range of 90-100 mmHg.
Marked symptomatic, orthostatic hypotension has been reported when calcium channel blockers and organic nitrates were used in combination. Dose adjustment of either class of agents may be necessary.
Nitrate therapy may aggravate the angina caused by hypertrophic cardiomyopathy.
Tolerance to this drug and cross tolerance to other nitrates and nitrites may occur.

Hypoxaemia.

Arterial oxygen tension decreases after administration of glyceryl trinitrate in normal subjects and in patients with coronary artery disease, and therefore it is advised that isosorbide dinitrate should be used cautiously in hypoxic patients because a decrease in available oxygen may oppose the antianginal effect of isosorbide dinitrate.

Haemolytic anaemia.

Isosorbide dinitrate has been reported to induce haemolytic anaemia in glucose-6-phosphate dehydrogenase deficient patients.

Relief of acute episodes of angina.

Oral isosorbide dinitrate tablets should not be administered for rapid relief of the pain of angina. Sublingual administration of isosorbide dinitrate tablets offers relatively fast relief.

Relief of left ventricular failure.

If left ventricular filling pressures are not elevated at the time isosorbide dinitrate is administered, the drug may cause severe hypotension due to a reduction in cardiac output.

Use in hepatic impairment.

Isosorbide dinitrate is, in part, metabolised by the liver and therefore impairment of liver function may necessitate a reduction in dosage.

Use in renal impairment.

In patients with renal failure, the plasma concentrations of isosorbide dinitrate and its active metabolites after single oral doses of the drug are not different from those seen in subjects with normal renal function. Although only 5% of a single dose of isosorbide dinitrate is excreted in the urine as the mononitrate metabolites, it is possible that with chronic dosing of isosorbide dinitrate, renal impairment could cause clinically significant accumulation of the active mononitrate metabolites (see Section 5.2 Pharmacokinetic Properties).

Use in the elderly.

In general, dose selection for an elderly patient should be cautious, usually starting at the low end of the dosing range, reflecting the greater frequency of decreased hepatic, renal or cardiac function, and of concomitant disease or other drug therapy.

Paediatric use.

As safety and efficacy have not been demonstrated for this age group, isosorbide dinitrate is not recommended for use in children.
These tablets should be used with caution in patients who are suffering from hypothyroidism, hypothermia, malnutrition, angle closure glaucoma.

Effects on laboratory tests.

No data available.

4.5 Interactions with Other Medicines and Other Forms of Interactions

Concurrent use of sildenafil can result in significant potentiation of the hypotensive effects of organic nitrates, such as isosorbide dinitrate, and is therefore contraindicated. Concomitant use of isosorbide dinitrate with phosphodiesterase inhibitors is contraindicated (see Section 4.3 Contraindications).
Patients receiving antihypertensive drugs or phenothiazines with nitrates should be observed for possible additive hypotensive effects.
Concomitant use with alcohol may cause hypotension due to an enhanced vasodilatory effect of isosorbide dinitrate.
Caution should be observed when giving tricyclic antidepressants and anticholinergic agents concomitantly with isosorbide dinitrate because these agents may potentiate the hypotensive effects of isosorbide dinitrate. Nonsteroidal anti-inflammatory drugs may attenuate the effects of isosorbide dinitrate, considering similar reports for glyceryl trinitrate.
The use of beta-adrenergic blocking agents may require a reduction in isosorbide dinitrate dosage if excessive hypotension is to be avoided.
Nitrate preparations can act as physiological antagonists to noradrenaline, acetylcholine, histamine and other agents.

4.6 Fertility, Pregnancy and Lactation

Effects on fertility.

No data available.
(Category B1)
The safety of isosorbide dinitrate in pregnancy has not been established. The drug should not be administered to pregnant women unless, in the opinion of the physician, the probable clinical benefits outweigh the possible hazards.
 It is not known whether isosorbide dinitrate or its metabolites are excreted in milk, or whether it has a harmful effect on the newborn. Therefore, it is not recommended for nursing mothers unless the expected benefits outweigh any potential risk.

4.7 Effects on Ability to Drive and Use Machines

The effects of this medicine on a person's ability to drive and use machines were not assessed as part of its registration.

4.8 Adverse Effects (Undesirable Effects)

Occasionally individuals may exhibit marked sensitivity to the hypotensive effects of nitrates, even with the usual therapeutic dosage.
Headache, dizziness, fatigue, palpitations, orthostatic hypotension, and flushing may occur at the beginning of treatment. These reactions are usually controlled by lowering the dose; and tend to decline with time.

More common reactions.

Nervous system.

Headache, which may be temporary or persistent, is the most common adverse reaction in patients treated with isosorbide dinitrate. Dizziness, especially postural.

Less common reactions.

Cardiovascular system.

Cutaneous dilatation with flushing; peripheral oedema, hypoxaemia. 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, collapse may occur (sometimes accompanied by bradyarrhythmia and syncope).

Dermatological.

Rash, exfoliative dermatitis, Stevens-Johnson syndrome.

Gastrointestinal.

Nausea, vomiting, pallor and excessive perspiration.

Haematological.

Haemolytic anaemia in patients with glucose-6-phosphate dehydrogenase deficient syndrome (see Section 4.4 Special Warnings and Precautions for Use).

Severe or life threatening reactions.

Severe hypotension and bradycardia may be hazardous, particularly in patients with cerebral or coronary atherosclerosis. Severe hypotension may lead to enhanced angina symptoms. Reflex tachycardia may exacerbate ischaemic injury in patients with acute myocardial infarction.

Reporting suspected adverse effects.

Reporting suspected adverse reactions after registration 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 at www.tga.gov.au/reporting-problems.

4.9 Overdose

Clinical features.

Overdosage of isosorbide dinitrate may result in severe hypotension and reflex tachycardia. Headache may be an indication of excessive dosage.

Management.

Following recent ingestion of large numbers of isosorbide dinitrate tablets, gastric lavage and administration of oxygen with assisted respiration may be necessary.
Hypotension and reflex tachycardia caused by overdosage can be treated by elevating the legs until the patient's condition stabilises. Since the duration of the haemodynamic effects following isosorbide dinitrate administration may be prolonged, additional corrective measures may be required. In that event, cautious administration of intravenous fluids or an alpha-adrenergic agonist (e.g. metaraminol) should be considered.
For information on the management of overdose, contact the Poisons Information Centre on 13 11 26 (Australia).

5 Pharmacological Properties

5.1 Pharmacodynamic Properties

Mechanism of action.

Antianginal, vasodilator.
Isosorbide dinitrate is an organic nitrate ester. It has a slower time to onset of action but longer duration of action than glyceryl trinitrate. The longer duration of action is due, in part, to the drug having a longer elimination half-life than glyceryl trinitrate and to the fact that its mononitrate metabolites are pharmacologically active and have long elimination half-lives (see Section 5.2 Pharmacokinetic Properties).
Like other organic nitrate ester drugs, the principal action of isosorbide dinitrate is to relax vascular smooth muscle. Venodilation causes venous pooling which reduces venous return, left ventricular filling pressure and pulmonary artery and capillary pressures. Myocardial oxygen requirements are also reduced. Arteriolar dilatation can result in a reduction in afterload. The clinical implication of these haemodynamic changes in patients with congestive heart failure can be an increase in cardiac output and a reduction in symptoms of pulmonary vascular congestion. Patients with angina pectoris attain relief through a reduction in myocardial oxygen requirements.
Nitrates may cause a redistribution of coronary blood flow to ischaemic areas by selectively dilating large coronary vessels or collateral vessels which may develop secondary to myocardial ischaemia.

Clinical trials.

No data available.

5.2 Pharmacokinetic Properties

Isosorbide dinitrate is absorbed faster after sublingual administration than after oral administration.
An oral availability of at least 20% means that the oral route is effective in providing significant amounts of isosorbide dinitrate for systemic pharmacological effects.
After chronic oral dosing at 6 hourly intervals, plasma levels of isosorbide dinitrate are greater than after single doses of the drug. This is associated with a reduced clearance of isosorbide dinitrate after chronic dosing.

Half-life.

An apparent terminal half-life of 1.1 to 1.3 hours has been reported for single oral and sublingual doses, and IV doses of isosorbide dinitrate. However, on monitoring plasma isosorbide dinitrate concentrations for up to 24 hours after chronic doses at 6 hourly intervals, a biexponential decay profile was reported with the first phase having a half-life of 1.1 hours and a second phase having a half-life of 7.7 hours. The first and faster half-life probably represents elimination of isosorbide dinitrate, while the second and slower half-life represents either protracted oral absorption or a redistribution of isosorbide dinitrate back from the peripheral tissues to the systemic circulation.
The apparent disappearance half-lives of the 2- and 5-mononitrate metabolites are about 3 hours and 4-6 hours respectively.
There are no differences in plasma levels of isosorbide dinitrate after single oral doses of the drug in normal subjects and renal failure patients, but because isosorbide dinitrate and its mononitrate metabolites accumulate with chronic dosing, significant accumulation of the drug and its metabolites may occur, particularly in patients with hepatic and/or renal failure.

5.3 Preclinical Safety Data

Genotoxicity.

No data available.

Carcinogenicity.

No data available.

6 Pharmaceutical Particulars

6.1 List of Excipients

The 5 mg tablets also contain the following excipients: cellulose-microcrystalline, erythrosine, lactose monohydrate, magnesium stearate, starch-maize.
The 10 mg, 30 mg and 40 mg tablets also contain the following excipients: ammonium phosphate-monobasic, cellulose-microcrystalline, lactose monohydrate, magnesium stearate, brilliant blue FCF (30 mg and 40 mg only), quinoline yellow (40 mg only), sunset yellow FCF (40 mg only).

6.2 Incompatibilities

Incompatibilities were either not assessed or not identified as part of the registration of this medicine.

6.3 Shelf Life

In Australia, information on the shelf life can be found on the public summary of the Australian Register of Therapeutic Goods (ARTG). The expiry date can be found on the packaging.

6.4 Special Precautions for Storage

Isordil sublingual tablets.

5 mg: store below 30°C.

Isordil oral tablets.

10, 30 and 40 mg: store below 25°C.

6.5 Nature and Contents of Container

Isordil sublingual tablets 5 mg.

20s* and 100s in bottles.

Isordil oral tablets 10 mg, 30 mg and 40 mg.

20s and 100's in bottles* and blister packs*.
* Currently not marketed.

6.6 Special Precautions for Disposal

In Australia, any unused medicine or waste material should be disposed of by taking to your local pharmacy.

6.7 Physicochemical Properties

Isosorbide dinitrate is fine, white or almost white, crystalline powder. It is very slightly soluble in water, very soluble in acetone, sparingly soluble in ethanol (96 percent).
Isosorbide dinitrate; also known as sorbide nitrate. The chemical name for isosorbide dinitrate is 1,4:3,6-dianhydro-2,5-di-O-nitro-D-glucitol.

Chemical structure.

Its structural formula is:
C6H8N2O8. Molecular weight: 236.1.

CAS number.

87-33-2.

7 Medicine Schedule (Poisons Standard)

Isordil Sublingual Tablets, 5 mg - S3 Pharmacist only Medicine.
Isordil Oral Tablets, 10 mg - S2 Pharmacy Medicine.
Isordil Oral Tablets, 30 mg - S4 Prescription only Medicine.
Isordil Oral Tablets, 40 mg - S4 Prescription only Medicine.

Summary Table of Changes