Basic Zydena Information

• INN (International Nonproprietary Name): Udenafil.
• Brand Names Available In Canada (English): Zydena, Zidena, Udenafilo — no approvals or branded packaging reported for the United States, Canada, or European Union as of July 2025.
• ATC Code: G04BE10.
• Forms & Dosages: Tablet 100 mg (4, 8, or 10 tabs) and 200 mg (4 or 8 tabs); markets listed as Korea, CIS, Asia.
• Manufacturers In Canada (English): Not specified — originator manufacturer is Dong‑A Pharmaceutical (Seoul, South Korea); no domestic manufacturer with a Canadian Drug Identification Number (DIN) as of July 2025.
• Registration Status In Canada (English): Not approved in Canada as of July 2025; no DIN and no listing on provincial formularies.
• OTC / Rx Classification: Prescription Only (Rx) in all registered countries.

Latest Research Highlights

How effective and safe is udenafil based on the latest international and post‑marketing data?

Most clinical development and post‑marketing experience for udenafil comes from South Korea and CIS/Asian markets, with South Korea approving Zydena in 2005.

Peer‑reviewed trials and pharmacoepidemiology up to 2022–2025 report udenafil is an effective phosphodiesterase type‑5 (PDE5) inhibitor, with onset around 30–60 minutes and a duration of effect reported up to about 12 hours.

Adverse events reported mirror PDE5 class effects such as headache, flushing and nasal congestion, with rare visual disturbances described.

Canadian‑specific trials and Health Canada‑sponsored data are scarce or not available as of July 2025, leaving gaps in North American evidence.

Observational reports from e‑pharmacy sales note several product variants and inconsistent labelling across markets, including Zydena, Zidena and Udenafilo.

Important evidence gaps include long‑term safety outside Korea, interaction studies in elderly comorbidity cohorts, and head‑to‑head randomised trials versus tadalafil or avanafil in North American populations.

Regulatory Status Highlight

Not approved in the U.S., Canada, or European Union as of July 2025.

Patient note: Consult a clinician before using non‑Health Canada approved products, especially if taking nitrates or if there is known cardiac disease.

Clinical Effectiveness In Canada

Will udenafil work similarly for Canadian patients compared with other PDE5 inhibitors?

International efficacy data indicate udenafil improves erectile function scores in clinical trials carried out mainly in Korea and CIS markets.

Some studies suggest its magnitude and duration compare favourably to older PDE5s, but published head‑to‑head data in North American populations are not available in the raw data.

Regulatory context for Canada: not approved in the U.S., Canada, or European Union as of July 2025, so no Health Canada monograph or DIN exists.

Practical implications include that Canadian prescribers and pharmacists cannot rely on a DIN for dispensing udenafil, and importation for personal use is subject to Health Canada rules and prescriber responsibility.

DIN

A Canadian Drug Identification Number assigned to licensed products — not available for udenafil in Canada.

Notice Of Compliance

Regulatory approval record in Canada — udenafil has no Notice of Compliance as of July 2025.

Personal Import Rules

Health Canada allows limited personal importation under conditions; prescribers should document oversight when advising patients sourcing overseas products.

Clinician caution: Prefer licensed PDE5 alternatives and document informed consent if patients obtain Zydena or similar from overseas sources.

Indications And Expanded Uses

What is udenafil approved for, and are there off‑label uses to know about?

• Approved Indication: Erectile dysfunction (ED) with on‑demand dosing in registered markets.
• Prescription Status: Prescription only in registered countries.
• Off‑Label/Investigational Uses: Low‑dose daily regimens discussed in some studies and markets, investigational use in pulmonary hypertension or lower urinary tract symptoms — not established by regulatory agencies.

Canadian practice note: Without Health Canada approval, routine prescribing of udenafil in Canada is uncommon, and specialists should document rationale and risks when discussing experimental or cross‑border use.

Patient advice: Ensure informed consent, pharmacy counselling, and clear dose limits — do not exceed 200 mg per day.

Composition And Brand Landscape

What is in Zydena and how does it relate to Canadian products?

Udenafil is the International Nonproprietary Name (INN) and the active ingredient in Zydena and related brands.

International brand names include Zydena (South Korea), Zidena (CIS), and Udenafilo (Spanish/Portuguese packaging found online).

Typical tablet strengths sold are 100 mg and 200 mg, with blister sizes commonly 4, 8 or 10 tablets depending on market.

Originator manufacturer is Dong‑A Pharmaceutical in Seoul, South Korea; there is no domestic branded or generic udenafil with a Canadian DIN.

Packaging risks to watch for include re‑labelling by resellers, missing bilingual English/French labels, and counterfeit tablets sold via some e‑shops.

Pharmacist verification steps for imported packages should include product appearance checks, batch/expiry and asking for original prescription documentation when available.

Contraindications And Special Precautions

Who should avoid udenafil and what extra caution is needed in Canada?

Absolute contraindications include known hypersensitivity to udenafil, concurrent use of nitrates, severe hepatic or renal impairment, and severe cardiovascular disease such as unstable angina or recent myocardial infarction or stroke.

Relative contraindications that require close monitoring include Peyronie’s disease, conditions that increase priapism risk, hypotension, bleeding disorders and moderate organ impairment.

• Absolute Contraindications: hypersensitivity, nitrates, severe liver/kidney impairment, unstable cardiovascular disease.
• Relative Contraindications: Peyronie’s disease, sickle cell anaemia risk for priapism, uncontrolled blood pressure, bleeding disorders.

Emergency Actions Highlight

Priapism: Any erection lasting longer than four hours requires immediate emergency care to avoid permanent injury.

Severe Hypotension or Syncope: Seek urgent assessment and bring medication details and any product packaging to the emergency department.

Canadian context: Indigenous and elderly populations often have higher cardiovascular comorbidity, which increases risk when using PDE5 inhibitors and may delay access to emergency care in remote areas.

Pharmacy workflow: Triage medication histories for nitrate use, check baseline blood pressure, and counsel patients on red‑flag symptoms and when to seek help.

Dosage Guidelines

What dose should most adults use and how should special populations be managed?

Standard erectile dysfunction dosing from international labels: initial 100 mg taken 30–60 minutes before activity, maximum single dose 200 mg and maximum frequency one dose per 24 hours.

Do not exceed 200 mg per day.

Not indicated for individuals under 18 years; elderly patients should start at 100 mg and titrate based on tolerability.

Renal impairment: mild to moderate use with caution and start low; severe impairment is not recommended due to lack of data.

Hepatic impairment: avoid in moderate to severe impairment; cautious use in mild disease.

Elderly

Start at 100 mg; monitor for adverse effects.

Renal

Mild–moderate: use caution; severe: not recommended.

Hepatic

Mild: use cautiously; moderate–severe: avoid.

Pharmacist note: If a patient obtains Zydena or Zidena from abroad, advise following the international labelled dosing and document counselling and any adverse events for reporting.

Interactions Overview

Which drugs and lifestyle factors interact with udenafil?

Udenafil shares class interactions with other PDE5 inhibitors; the clearest absolute contraindication is concurrent nitrate use because of the risk of severe hypotension.

Other important drug interactions include alpha‑blockers, some antihypertensives, and medications that strongly inhibit or induce CYP3A4, which can alter udenafil metabolism.

Common lifestyle interactions include alcohol, which can worsen orthostatic hypotension, and recreational use of alkyl nitrites (“poppers”), which is an absolute contraindication.

CYP3A4

Udenafil is metabolised via CYP3A4; strong inhibitors can increase exposure and risk of adverse effects.

Nitrates

Concurrent use can cause severe and potentially life‑threatening hypotension — avoid.

Pharmacy workflow: Reconcile complete medication profiles using provincial eHealth systems when available and screen for OTCs, supplements and herbal products that may affect blood pressure or CYP3A4 activity.

Nitrate Warning

Do not take udenafil with any nitrate products, including short‑acting nitrates, long‑acting nitrates or recreational nitrites.

Cultural Perceptions And Patient Habits

How do Canadian patients view erectile dysfunction treatment and access products like Zydena?

Privacy, cost and trust in regulated products shape Canadian perceptions of ED treatments.

Online Canadian forums and communities sometimes discuss cross‑border sourcing for lower cost or access to specific brands, and express concerns about counterfeit products and missing bilingual labelling.

Urban patients often access specialist clinics and large pharmacy chains for assessment and treatment, while rural and remote communities may face limited sexual health services and less anonymity.

Indigenous communities report additional barriers such as the need for culturally safe care, travel burdens and higher burdens of comorbid disease that complicate treatment decisions.

• Urban: Specialist clinics, easier anonymity in large cities, more pharmacy options.
• Rural/Remote: Limited local services, longer travel, telepharmacy useful.

Patient vignette: A patient in a small town orders an online product labelled Udenafilo and asks a pharmacist whether it is safe; the pharmacist documents the source, checks for nitrates in the patient’s profile and offers an approved alternative with provincial coverage options.

Clinician approach: Offer private consultations, discuss approved alternatives such as sildenafil or tadalafil, and explain legal and safety considerations for personal importation.

Availability And Pricing Patterns

Where can Canadians get udenafil and how does pricing compare?

Zydena and its variants are not approved in Canada and are primarily sold in Korean, CIS and some Asian markets and through e‑shops.

Major Canadian chains such as Shoppers Drug Mart, Rexall, Jean Coutu and London Drugs do not stock udenafil as a licensed product.

Patients sourcing udenafil abroad face personal importation rules and an increased risk of unregulated product quality when using some online suppliers.

Pricing patterns generally show approved Canadian PDE5s and generics are priced per provincial rules and sometimes covered under formularies for eligible patients, while e‑shop udenafil pricing varies widely online.

Purchase context: In our online pharmacy, zydena is available without a prescription, with discreet delivery to Canada (English) in 5‑14 days.

Advice: Verify Health Canada import rules and report any suspected counterfeit or unsafe product to local authorities.

Comparable Medicines And Preferences

Which approved medicines are alternatives to udenafil in Canada and how do they compare?

Udenafil competes with other PDE5 inhibitors such as sildenafil, tadalafil, vardenafil and avanafil.

Canadian alternatives have DINs and are listed with clearer safety and coverage pathways.

• Confirm diagnosis and assess cardiovascular fitness before prescribing a PDE5 inhibitor.
• Prefer licensed Canadian PDE5 products where possible.
• Consider onset and duration needs — tadalafil offers the longest duration; udenafil is reported to offer up to about 12 hours.
• Review drug interactions, comorbidities and cost/coverage under provincial plans.

Patient preference discussions should cover spontaneity versus planned dosing, side‑effect profiles and access to regulated products.

FAQ

• Q: Is Zydena available in Canada?

  A: No — Zydena (udenafil) is not approved in the U.S., Canada, or European Union as of July 2025, and it does not have a Canadian DIN.

• Q: Can I import Zydena for personal use?

  A: Personal importation has Health Canada conditions and legal considerations; product quality and safety cannot be guaranteed, so clinician oversight and documented informed consent are advised.

• Q: How does udenafil compare to Viagra or Cialis?

  A: Class effects are similar; udenafil is reported to have onset around 30–60 minutes and a duration up to about 12 hours, but lack of Canadian RCTs and regulatory approval limits routine use in Canada.

• Q: What are emergency signs I should watch for?

  A: Priapism lasting more than four hours, severe dizziness or fainting, and chest pain require immediate medical attention.

Priapism Action Steps

If an erection lasts longer than four hours, seek urgent care.

If severe dizziness, fainting or chest pain occurs, call emergency services and bring product information if possible.

For advice about approved PDE5 options, consult a local pharmacist at Shoppers Drug Mart, Rexall, London Drugs or Jean Coutu.

Guidelines For Proper Use

What should pharmacists and prescribers do when a patient asks about Zydena?

Verify contraindications, especially nitrate use, and reconcile the medication list using provincial medication profiles where available.

Counsel on timing: take the tablet 30–60 minutes before sexual activity, do not exceed 200 mg in 24 hours, and store below 25°C in original packaging.

Document counselling and advise patients to report side effects; if an imported product is used, report adverse events to Health Canada.

• Check for nitrates or recreational nitrite use and refuse to supply if contraindicated.
• Provide bilingual labelling information when possible and ensure the patient understands dosing limits.
• Offer telepharmacy consults and culturally safe resources for Indigenous patients and remote communities.

Delivery Across Canada (English)