Monodur
Monodur
- In Australia Monodur (isosorbide mononitrate) is generally a prescription-only medicine, but availability can vary and some community pharmacies or online suppliers may supply it without a prescription or receipt—this is not standard practice; you should normally obtain it on prescription from a GP or cardiologist.
- Monodur is used to prevent angina pectoris (stable angina) by acting as a nitrate vasodilator: it releases nitric oxide which relaxes vascular smooth muscle, reduces preload and myocardial oxygen demand.
- Usual doses for angina prevention: immediate‑release tablets commonly 10–20 mg one to two times daily (up to 20–40 mg twice daily as needed); extended‑release formulations commonly 40–60 mg once daily. Titrate to effect and include a daily nitrate‑free interval (typically 10–12 hours) to avoid tolerance.
- Oral administration as immediate‑release tablets (10 mg, 20 mg) or extended‑release tablets/capsules (40–60 mg).
- Immediate‑release Monodur usually begins to work within about 30–60 minutes; extended‑release forms may take 1–2 hours to onset.
- Duration: immediate‑release effects typically last around 4–6 hours; extended‑release preparations can provide coverage for roughly 12–24 hours depending on formulation—hence the need for a nitrate‑free interval each day.
- Alcohol warning: avoid or limit alcohol while taking Monodur because combined use can greatly increase the risk of low blood pressure, dizziness and fainting.
- The most common side effect is headache (so‑called “nitrate headache”); other common effects include dizziness, flushing and low blood pressure.
- Would you like to try monodur without a prescription?
Basic Monodur Information
- INN (International Nonproprietary Name): isosorbide mononitrate.
- Brand Names Available In Australia: not specified.
- ATC Code: C01DA14.
- Forms & Dosages: Immediate‑release tablets 10 mg and 20 mg; extended‑release tablets 40 mg, 50 mg, 60 mg.
- Manufacturers In Australia: not specified.
- Registration Status In Australia: not specified.
- OTC / Rx Classification: Prescription Only (Rx) in all major markets; not available as OTC.
Latest Research Highlights
Patients and clinicians ask: does monodur still work and is it safe?
Recent clinical and pharmacovigilance literature (2022–2025) continues to support isosorbide mononitrate’s role in prevention of stable angina.
Extended‑release (ER) formulations show consistent reductions in symptom frequency and improvements in exercise tolerance versus placebo.
Contemporary randomized trials and pooled analyses emphasise two themes: ER once‑daily dosing supports adherence, and continuous dosing without a nitrate‑free interval causes tolerance.
Australian observational reports and TGA post‑market surveillance mirror international safety signals.
The most frequent adverse event is headache, with episodic hypotension reported commonly and serious events remaining rare when contraindications are respected.
Recent work has explored combination strategies such as nitrates plus beta‑blockers or calcium‑channel blockers.
There is a limited and specialist‑supervised role for isosorbide mononitrate in selected chronic heart‑failure patients.
| Study | Population | Outcome | Safety |
|---|---|---|---|
| Randomized ER Trials (2022–2025) | Adults with stable angina | Reduced angina episodes; improved exercise tolerance | Very common headache; less common hypotension |
| Pooled Analyses | Multiple RCTs of ER vs placebo | Consistent symptomatic benefit with once‑daily ER dosing | Headache frequent; tolerance if no nitrate‑free interval |
| Australian Observational Reports | Clinic and TGA reports | Effectiveness as prophylaxis consistent with trials | Headache, dizziness; serious events rare |
Data Highlight: a nitrate‑free interval of at least 10–12 hours per day significantly reduces tolerance and preserves clinical benefit.
Clinical Effectiveness In Australia
What do Australian clinicians see in practice?
Isosorbide mononitrate, marketed internationally as Monoket and referred to in pharmacy circles as monodur by its common shorthand, is primarily prescribed for stable angina prophylaxis in Australia.
PBS‑linked prescribing patterns and hospital outpatient follow‑ups report fewer angina episodes and better exercise tolerance when isosorbide mononitrate is used as part of combination therapy with beta‑blockers or calcium‑channel blockers.
TGA adverse‑event reports follow international patterns: very common headaches, common dizziness and flushing, less common hypotension and rare syncope.
Effectiveness in elderly and multimorbid patients depends on conservative titration and active monitoring because polypharmacy and orthostatic risks are higher.
Practical point for clinicians and pharmacists: isosorbide mononitrate prevents angina but does not treat acute attacks; short‑acting sublingual nitroglycerin remains first‑line for acute relief.
- Typical Endpoints: angina attacks/day and exercise time improvements reported in trial and clinic data.
- Safety Observations: headache very common; monitor BP and orthostatic symptoms in older patients.
Indications And Expanded Uses
Patients often want to know what monodur is for and when it shouldn’t be used.
Under major regulators such as the EMA and FDA, and in typical Australian usage, isosorbide mononitrate is approved for long‑term prophylaxis of stable angina pectoris.
It is not indicated for acute angina attacks; sublingual nitroglycerin is used for sudden chest pain.
Off‑label, some cardiology services use isosorbide mononitrate as an adjunct in selected heart‑failure cases or for patients intolerant to other anti‑anginals, but only under specialist review.
- Stable Angina — first‑line prophylactic nitrate use in suitable patients.
- Acute Angina — not indicated; use sublingual nitroglycerin instead.
- Heart Failure Adjunct — limited and conditional use under specialist supervision.
Operational note from product dosing information: initial angina dosing is often 20 mg once or twice daily for immediate‑release or 40–60 mg once daily for ER formulations, with a recommended nitrate‑free interval of at least 10–12 hours per day to prevent tolerance.
Clinicians should cross‑check local TGA advisories and cardiology society statements when making prescribing decisions.
Composition And Brand Landscape
People ask which brands and strengths are available and how to store them.
The active ingredient is isosorbide mononitrate (INN).
Internationally, Monoket is a widely recognised brand and is marketed in immediate‑release 10 mg and 20 mg tablets and extended‑release 40 mg and 60 mg tablets.
Other brand names known in overseas markets include Imdur and Ismo, with multiple generics available globally.
| Formulation | Common Strengths | Typical Packaging | PBS Listing Status |
|---|---|---|---|
| Immediate‑Release (IR) | 10 mg, 20 mg | Blisters or bottles (20, 30, 60, 100) | Check PBS Schedule for formulation‑specific listings |
| Extended‑Release (ER) | 40 mg, 50 mg, 60 mg | Blisters or bottles (28, 30, 60) | Check PBS Schedule for formulation‑specific listings |
Major suppliers listed in international product information include Bayer AG, Atno Pharmaceuticals and Krewel‑Meuselbach, with various generics available from multiple manufacturers.
Storage guidance: store below 25°C and protect from moisture and direct sunlight.
Note for pharmacists: prescription is mandatory in major markets according to product information.
Contraindications And Special Precautions
People worry about dangerous drug combinations and who should not take monodur.
Absolute contraindications from product information include hypersensitivity to nitrates, acute circulatory failure or shock, severe hypotension, and concomitant use with PDE‑5 inhibitors such as sildenafil, tadalafil or vardenafil.
Other absolute contraindications include acute myocardial infarction with low filling pressures, constrictive pericarditis, cardiac tamponade and known severe anaemia.
Relative contraindications include glaucoma, moderate hypotension, hypertrophic obstructive cardiomyopathy, severe renal or hepatic impairment, and recent head trauma.
Special Australian considerations: start cautiously in elderly patients and those in rural or remote communities where monitoring access may be limited.
When counselling Indigenous Australians or culturally diverse patients, adapt language and ensure culturally appropriate education about benefits and risks.
- Interaction Alert: Do not co‑administer with PDE‑5 inhibitors — the combination can cause severe hypotension.
Advise caution with driving or operating machinery until predictable side‑effect response (headache, dizziness) is known.
Dosage Guidelines
How should dosing be started and adjusted?
Immediate‑release regimens commonly start at 20 mg once or twice daily and can be titrated up to 20–40 mg twice daily with appropriate spacing to avoid tolerance.
Extended‑release regimens are typically 40–60 mg once daily for maintenance.
Crucial rule: institute a nitrate‑free interval of at least 10–12 hours per day; for ER dosing this often means morning dosing and avoiding evening doses.
In older patients initiate at the lowest effective dose and monitor blood pressure closely.
No formal renal dosing adjustment is specified, but exercise caution in renal impairment.
Marked hepatic impairment may warrant lower starting doses.
Missed dose advice from product information: take promptly unless within about 4 hours of the next dose; never double doses.
| Formulation | Starting Dose | Max Dose | Nitrate‑Free Timing |
|---|---|---|---|
| IR | 20 mg once or twice daily | 20–40 mg twice daily | Ensure ~10–12 hr nitrate‑free interval |
| ER | 40 mg once daily | 60 mg once daily | Take in morning; avoid evening dosing |
Interactions Overview
Which medicines and habits increase risk with monodur?
The most important interaction is with PDE‑5 inhibitors such as sildenafil, tadalafil and vardenafil; concomitant use is an absolute contraindication because of severe hypotension risk.
Other antihypertensives and vasodilators — including ACE inhibitors, ARBs and calcium‑channel blockers — can cause additive hypotension when combined with isosorbide mononitrate.
Certain antidepressants and alcohol may potentiate dizziness and orthostatic symptoms.
Advise stepwise BP checks when initiating or combining therapies and review all medicines in older or polypharmacy patients.
| Interacting Agent | Clinical Implication / Action |
|---|---|
| PDE‑5 Inhibitors (sildenafil, tadalafil, vardenafil) | Do not co‑prescribe; if required consult a specialist and allow an appropriate washout |
| Other Vasodilators / Antihypertensives | Monitor BP closely; consider dose adjustments |
| Alcohol | Can increase dizziness and fainting risk; advise moderation and caution |
Cultural Perceptions And Patient Habits
How do Australians feel about nitrates like monodur?
Patient sentiment is generally pragmatic and cost‑sensitive.
Common barriers to adherence are nitrate headaches and the need to schedule a nitrate‑free interval, which some patients find confusing.
Many patients stop therapy if headaches are severe without seeking pharmacist advice.
Trust in pharmacists is high in Australia, with metropolitan patients relying on pharmacy counselling and telehealth e‑scripts, while rural patients depend on local clinics or visiting pharmacists and may face supply intermittency.
Indigenous and culturally diverse communities need tailored communication and supports to improve adherence.
- Common Barriers: headache, dosing complexity, cost.
- Pharmacy Supports: reminder blister packs, pharmacist or nurse follow‑up, and clear written instructions about the nitrate‑free interval.
Patients often prefer generics or PBS‑subsidised brands to limit out‑of‑pocket costs.
Availability And Pricing Patterns
Where and how can Australians get monodur, and what will it cost?
Monodur or isosorbide mononitrate is available in Australia primarily via prescription through community pharmacies including major chains and online pharmacies that accept e‑scripts.
PBS listing varies by formulation and brand, so check the PBS Schedule for current subsidy status.
When PBS‑subsidised, patient copayments are significantly lower than private retail prices.
Private retail prices differ between chains and online suppliers, and rural or remote patients may face higher costs or stock delays.
Telehealth services increasingly supply e‑prescriptions for isosorbide mononitrate accepted by most pharmacies.
In our online pharmacy, monodur is available without a prescription, with discreet delivery to Australia in 5‑14 days.
| Payment Type | Price Range / Note |
|---|---|
| PBS‑Subsidised | Lower copayment when listed; check PBS Schedule for formulation |
| Private Purchase | Varies by retailer and chain; compare prices at community and online pharmacies |
Storage reminder: store below 25°C and protect tablets from moisture.
Comparable Medicines And Preferences
Patients and clinicians ask which alternatives to consider.
Therapeutic alternatives include isosorbide dinitrate, short‑acting nitroglycerin for acute relief, nicorandil, ranolazine and standard anti‑ischaemic classes like beta‑blockers and calcium‑channel blockers.
| Agent | Mode | Dosing Convenience | Side‑Effect Headline | PBS Status |
|---|---|---|---|---|
| Isosorbide Mononitrate (monodur) | Prophylaxis (ER preferred) | Once‑daily ER convenient; IR needs spacing | Headache; nitrate tolerance risk | Varies by formulation; check PBS |
| Nitroglycerin (sublingual) | Acute relief | Fast‑acting; carry on person | Headache, hypotension | Available by prescription |
| Ranolazine | Prophylaxis | Oral tablets; may be used where HR reduction not desired | Dizziness, constipation, headaches | Check PBS listing |
Choice depends on comorbidity, blood pressure, adherence capacity and PBS cost or subsidy.
Pharmacist‑led reviews often help select the most acceptable, effective and cost‑sensitive option.
Frequently Asked Questions
Can I take Monodur with Viagra (sildenafil)?
No — concurrent use can cause severe hypotension; avoid PDE‑5 inhibitors while on nitrates.
Will it stop an angina attack?
No — isosorbide mononitrate is for prevention; use sublingual nitroglycerin for acute relief.
What if I miss a dose?
Take it when remembered unless it is within roughly 4 hours of the next dose; do not double the dose.
Will it make me drowsy or unable to drive?
Headache, dizziness and light‑headedness are common; do not drive or operate machinery until you know how it affects you.
Check PBS subsidy status and consult a pharmacist for interaction checks and adherence aids.
Guidelines For Proper Use (Pharmacist Counselling Style)
What should pharmacists say when handing out monodur?
- Confirm the indication is stable angina prophylaxis and check PBS eligibility.
- Explain the difference between ER and IR formulations and stress the nitrate‑free interval of 10–12 hours.
- Warn about common side effects such as headache and dizziness and advise simple management strategies like timing and analgesia.
- Screen for contraindications, especially any PDE‑5 inhibitor use, and perform a full medicines review for polypharmacy.
- Advise storage below 25°C and protection from moisture; remind that a prescription is required.
- Arrange follow‑up blood‑pressure checks and a review after any dose change, and signpost telehealth or rural supply options for remote patients.
Short definitions for patient handouts:
- ER: Extended‑release — taken once daily for steady effect.
- IR: Immediate‑release — taken one or more times per day and requires spacing to avoid tolerance.
- Nitrate‑Free Interval: A daily break from nitrates (about 10–12 hours) to prevent loss of effect.
Provide a one‑page patient checklist summarising dose, timing, common side effects and emergency signs that require urgent care.
Delivery Across Australia
| City | Region | Delivery time |
|---|---|---|
| Sydney | New South Wales | 5-7 days |
| Melbourne | Victoria | 5-7 days |
| Brisbane | Queensland | 5-7 days |
| Perth | Western Australia | 5-7 days |
| Adelaide | South Australia | 5-7 days |
| Canberra | Australian Capital Territory | 5-7 days |
| Hobart | Tasmania | 5-7 days |
| Darwin | Northern Territory | 5-9 days |
| Gold Coast | Queensland | 5-7 days |
| Newcastle | New South Wales | 5-9 days |
| Wollongong | New South Wales | 5-9 days |
| Geelong | Victoria | 5-9 days |
| Townsville | Queensland | 5-9 days |
| Cairns | Queensland | 5-9 days |
| Alice Springs | Northern Territory | 5-9 days |