Basic Ismo Information

• INN (International Nonproprietary Name): Monoket is the brand name; its INN is isosorbide mononitrate.
• Brand Names Available In Canada (English): not specified.
• ATC Code: C01DA14.
• Forms & Dosages: Immediate‑release oral tablets 10 mg and 20 mg; extended‑release tablets/capsules 40 mg, 50 mg and 60 mg.
• Manufacturers In Canada (English): not specified.
• Registration Status In Canada (English): not specified.
• OTC / Rx Classification: Prescription Only (Rx) in major markets.

Latest Research Highlights

Are you wondering whether isosorbide mononitrate still works for preventing chest pain and whether it helps people live longer?

High‑quality regulatory approvals exist in multiple jurisdictions for isosorbide mononitrate, and the product is classified under ATC code C01DA14.

Randomised Canadian trials specifically named in public datasets are not specified in the supplied data.

Most registration and trial evidence referenced for Monoket and related products comes from international submissions to the EMA and FDA as indicated in product registration summaries.

Consistent findings reported in international experience include symptom reduction for stable angina and predictable adverse events such as nitrate headache and hypotension.

Tolerance or tachyphylaxis develops when nitrates are given continuously without a nitrate‑free interval.

Pharmacovigilance up to recent years highlights headaches as very common and flags the critical interaction with PDE‑5 inhibitors.

Patient‑centred work in Canada notes adherence challenges tied to dosing schedules and rural access to titration and monitoring.

Data Highlight: ATC C01DA14 places isosorbide mononitrate in cardiac therapy under nitrates.

Data Highlight: Immediate‑release (IR) and extended‑release (ER) formulations exist, with ER designed for once‑daily dosing.

Data Highlight: The product is listed on the WHO Essential Medicines List for angina treatment.

Key Terms

• IR (Immediate Release): Tablets that release active drug quickly after ingestion.
• ER (Extended Release): Formulations that release drug over many hours to allow once‑daily dosing.
• Tachyphylaxis: Loss of effect with continuous nitrate exposure unless a nitrate‑free interval is provided.

Clinical Effectiveness In Canada

Do Canadian clinicians get the same benefits from isosorbide mononitrate as described internationally?

Health Canada recognitions align with international approvals for chronic angina prophylaxis although explicit Canadian registration details are not specified in the supplied data.

In practice, effectiveness is judged by improved symptom control, better exercise tolerance, and reduced need for rescue sublingual nitroglycerin.

Clinicians consult Health Canada product monographs, provincial formularies and specialty guidance when selecting therapy and dosing.

Access is variable across Canada with urban specialty clinics typically supporting closer titration and rural primary care managing maintenance therapy.

• Health Canada monograph and product monograph review.
• Provincial formularies such as Ontario Drug Benefit, BC PharmaCare, RAMQ for coverage checks.
• Canadian Cardiovascular Society guidance and specialty consultation when needed.

Pharmacy practice note: check the Drug Identification Number (DIN) if a product is marketed in Canada and confirm bilingual English/French labelling requirements.

Indications And Expanded Uses

What is isosorbide mononitrate prescribed for, and when should it not be used?

The primary approved indication is prevention of stable (chronic) angina pectoris rather than acute relief of angina attacks.

Sublingual nitroglycerin remains the recommended option for acute chest pain episodes.

Selected specialists may use isosorbide mononitrate off‑label as an adjunct in some heart‑failure patients under close monitoring.

IR dosing usually involves twice‑daily spacing while ER strategies rely on once‑daily dosing with a nitrate‑free interval of about 10–12 hours.

Definitions

• Approved Indication: Chronic angina prophylaxis as per product dosing tables.
• Off‑Label Uses: Use without formal approval for a specific indication; requires specialist oversight.
• Nitrate‑Free Interval: A daily period (typically 10–12 hours) without nitrate exposure to reduce tolerance.

• Prescriber Checklist For Canada: confirm indication and symptom pattern.
• Rule out concurrent PDE‑5 inhibitor use before starting therapy.
• Review baseline blood pressure and consider renal/hepatic status.
• Check provincial formulary rules for coverage of off‑label uses.

Composition And Brand Landscape

Which brands and formulations contain isosorbide mononitrate?

The active ingredient is isosorbide mononitrate (INN), sold internationally under brand names such as Monoket, Ismo and Imdur, plus many generics.

Available formulations include immediate‑release tablets (10 mg, 20 mg) and extended‑release tablets (40 mg, 50 mg, 60 mg).

Packaging varies by country and manufacturer and commonly uses blister packs of 20, 28, 30 or 60 tablets.

• Pharmacy Channels: Shoppers Drug Mart, Rexall, Jean Coutu, London Drugs and accredited Canadian online pharmacies — prescriptions are required in major markets.
• Product Synonyms For Search: Monoket, Ismo, Imdur, isosorbide‑1‑mononitrate.

Contraindications And Special Precautions

Who should not take isosorbide mononitrate and who needs closer monitoring?

Absolute contraindications include hypersensitivity to nitrates, severe hypotension, acute circulatory failure, and concomitant use with PDE‑5 inhibitors such as sildenafil or tadalafil.

Other absolute contraindications in product summaries include acute myocardial infarction with low filling pressures, constrictive pericarditis and known severe anaemia.

Relative contraindications include glaucoma, hypertrophic obstructive cardiomyopathy, and severe renal or hepatic impairment where caution is advised.

• Absolute Contraindications: Hypersensitivity to nitrates; severe hypotension; acute circulatory failure; use with PDE‑5 inhibitors.
• Relative Contraindications: Glaucoma; moderate hypotension; hypertrophic obstructive cardiomyopathy; severe renal/hepatic impairment.

Data Highlight: The interaction with PDE‑5 inhibitors is clinically important and can cause profound hypotension.

Special Canadian patient groups at higher risk include elderly patients with polypharmacy and populations with higher cardiovascular comorbidity burden.

Culturally safe practice requires screening for traditional remedies and arranging interpreter support for Francophone and Indigenous language needs.

Dosage Guidelines

How should isosorbide mononitrate be dosed safely and practically in Canada?

Standard initiation for IR formulations is often 20 mg once or twice daily with titration up to 20–40 mg twice daily as needed for symptom control.

ER formulations are commonly prescribed 40–60 mg once daily, with a required nitrate‑free interval of about 10–12 hours to prevent tolerance.

Canadian prescribers should document the dosing window and advise patients to take ER doses to preserve the nightly nitrate‑free period.

• Stepwise titration: start low, reassess symptom relief in several days, up‑titrate cautiously for hypotension or headaches.
• Elderly and those with hepatic or renal impairment: start at the lowest effective dose and monitor closely.
• Missed dose advice: take as soon as remembered unless close to the next dose; do not double doses.

Pharmacist counselling points: never double a missed dose, seek urgent care for syncope, and report severe or persistent hypotension.

Note that some provincial plans may favour short initial fills during trial periods for coverage purposes.

Interactions Overview

Which drugs and substances are risky to use with isosorbide mononitrate?

The most dangerous interaction is with PDE‑5 inhibitors such as sildenafil, tadalafil and vardenafil; co‑administration is contraindicated.

Other interactions include additive hypotension with alcohol, antihypertensives and other vasodilators.

• High‑risk Interactions To Screen: PDE‑5 inhibitors, riociguat, other nitrates, potent vasodilators, and heavy alcohol use.
• Advice For Records: flag interaction risk in electronic medical records to prevent accidental co‑prescribing, especially for telemedicine patients.

Patient counselling should emphasise avoiding over‑the‑counter PDE‑5 analogues purchased online and reporting all medicines including supplements.

Cultural Perceptions And Patient Habits

What do Canadian patients say about taking isosorbide mononitrate?

Patients often report nitrate headaches and frustration with dosing windows required to maintain a nitrate‑free interval.

Cost and coverage concerns appear frequently on community forums and influence adherence in some groups.

Urban patients generally have better access to specialist titration while rural patients may rely on primary care for dose adjustments.

Indigenous and newcomer populations often prefer oral explanations and culturally safe counselling with interpreter support when needed.

• Common Patient Complaints: headaches, dosing inconvenience, variability in provincial coverage.
• Culturally Adapted Counselling Tips: use plain language, confirm understanding, involve community health workers for Indigenous patients.

Availability And Pricing Patterns

Where do Canadians buy isosorbide mononitrate and what does it cost?

Global manufacturers include Bayer, Atno and Krewel‑Meuselbach and numerous generics; Canadian stocking depends on distributor agreements and DIN approval.

Pricing and reimbursement vary by provincial formularies and by national pharmacy chains such as Shoppers Drug Mart, Rexall, Jean Coutu and London Drugs.

Cross‑border purchasing is practiced by some, but prescription transfer, regulatory and safety differences apply.

• Pharmacy Purchase Routes: community brick‑and‑mortar, accredited online Canadian pharmacies (require prescription), and cross‑border pharmacies with legal caveats.
• Coverage Note: check ODB, BC PharmaCare and RAMQ formularies for specific listings and criteria.

In our online pharmacy, ismo is available without a prescription, with discreet delivery to Canada in 5–14 days.

Comparable Medicines And Preferences

What are the alternatives to isosorbide mononitrate and how do they compare?

Therapeutic alternatives available include isosorbide dinitrate for shorter acting nitrate coverage, nitroglycerin for acute relief, nicorandil, ranolazine and standard first‑line agents such as beta‑blockers and calcium‑channel blockers.

• Pros/Cons Checklist For Choosing Monoket: ER offers once‑daily convenience but requires nitrate‑free interval; IR allows flexible dosing but needs more frequent administration.
• Patient Preference: some choose fewer doses per day; others prioritise minimal headaches or avoidance of hypotension.

FAQ

Can I take isosorbide mononitrate with PDE‑5 inhibitors?

No — this is contraindicated due to the risk of severe hypotension. Consult a clinician before starting either drug.

Is Monoket safe for older adults?

Start at a low dose and monitor blood pressure and orthostatic symptoms closely; adjust as needed.

Do I need a nitrate‑free interval?

Yes — typically 10–12 hours per day to prevent tolerance and preserve effectiveness.

Is this medication covered by provincial drug plans?

Coverage varies by province and formulation; check ODB, BC PharmaCare and RAMQ and include the DIN on prescriptions if available.

What if I miss a dose?

Take as soon as remembered unless it is close to the next dose; do not double up.

Guidelines For Proper Use

How should pharmacists and prescribers manage isosorbide mononitrate safely?

Confirm the diagnosis of stable angina before initiating therapy and review all current medications with emphasis on PDE‑5 inhibitors.

Counsel patients on the need for a nitrate‑free interval and how to recognise hypotension and severe headaches.

Document the DIN and bilingual product information when dispensing products marketed in Canada.

• Initiation: baseline BP and orthostatics, symptom diary and rescue nitroglycerin review.
• Titration: increase dose gradually and reassess within days of changes.
• Monitoring: BP checks after initiation and after up‑titration; evaluate tolerance and side effects.
• Deprescribing: taper or stop if intolerable adverse effects or lack of benefit.

Monitoring Parameters

• Baseline BP: before starting therapy.
• Orthostatic Vitals: at initiation and after dose increases.
• Symptom Diary: track angina frequency and use of rescue nitroglycerin.

For rural patients, arrange telepharmacy follow‑up or community clinic monitoring, and for Indigenous settings engage culturally appropriate health workers for shared decision making.

Delivery Across Canada (English)