Basic Zydena Information

• INN (International Nonproprietary Name): Udenafil.
• Brand Names Available In United Kingdom: Not available / No authorised Zydena brands in the United Kingdom or EU as of July 2025.
• ATC Code: G04BE10.
• Forms & Dosages: Tablets typically 100 mg (4, 8 or 10 tab blisters) and 200 mg (4 or 8 tab blisters) sold in Korea, CIS and parts of Asia.
• Manufacturers In United Kingdom: Not specified.
• Registration Status In United Kingdom: Not approved in the European Union or United Kingdom as of July 2025; approved in South Korea (Zydena) since 2005 and registered in some CIS markets.
• OTC / Rx Classification: Prescription Only (Rx) where registered; not authorised in the UK as of July 2025.

Latest Research Highlights

Are you wondering what the latest clinical evidence says about udenafil for erectile dysfunction?

UK and EU clinical literature specifically on udenafil is limited, with most primary trials and pharmacology originating from South Korea where Zydena has been authorised since 2005.

Systematic randomised controlled trials in the UK and EU between 2022 and 2025 are sparse, and recent reports are mainly observational or regionally focused in Asia and the CIS.

Key reproducible findings across published sources include an onset of effect around 30–60 minutes and an effect duration reported up to about 12 hours.

Common adverse events mirror other phosphodiesterase type‑5 inhibitors, including headache, flushing, nasal congestion and dyspepsia.

Absolute contraindications recorded repeatedly include concurrent nitrate therapy and severe hepatic or renal impairment.

Regulatory status is important for UK readers: as of July 2025 there is no MHRA or EMA marketing authorisation for Zydena or udenafil.

Evidence quality is moderate for short‑term on‑demand efficacy but limited for long‑term safety data in European populations.

For comparison with licensed agents like sildenafil, tadalafil and vardenafil, more UK/EU trial data and post‑marketing surveillance are needed to close regulatory gaps.

Suggested quick table for readers: study design, sample size, primary efficacy and safety signals — UK/EU entries are mostly "not available" versus multiple South Korean and CIS entries.

Clinical Effectiveness In The UK

Are patients in the UK likely to experience benefits similar to those described in international trials?

Because udenafil (Zydena) lacks MHRA and EMA approval, there are no NHS outcome data and UK effectiveness is inferred from South Korean trials and international observational reports.

Private clinics and patients who import products commonly report improved erections, greater sexual satisfaction and a prolonged window of effect, often quoted up to 12 hours.

Onset is typically described as 30–60 minutes, which places udenafil between fast‑onset agents like avanafil and longer‑acting tadalafil by patient experience.

Challenges in the UK context include variable product quality when sourced online, inconsistent labelling and the absence of UK‑specific pharmacovigilance data.

Forum and patient portal feedback shows a preference among some men for the longer action but concern about side‑effect monitoring and drug interactions with cardiovascular medications.

NHS clinicians would treat udenafil as an unlicensed medicine and document informed consent, perform a cardiovascular risk assessment and consider licensed PDE5 inhibitors such as sildenafil, tadalafil, vardenafil and avanafil first.

For patients choosing private routes, pharmacists should advise on checking provenance, batch numbers and seeking GP review for continued use.

Patient‑reported advantages versus risks: advantage — longer effective window; risk — lack of regulated supply, unknown long‑term safety in UK populations.

Indications And Expanded Uses

What is udenafil authorised to treat, and can it be used for anything else?

Registered indication for udenafil in authorised markets is the treatment of erectile dysfunction, with Zydena marketed by Dong‑A Pharmaceutical for on‑demand use.

Manufacturer labelling recommends an initial dose of 100 mg taken as needed 30–60 minutes before sexual activity, with a maximum single dose of 200 mg and no more than one dose per 24 hours.

In the United Kingdom there is no MHRA approval, so no licensed indication exists domestically and the NHS has no formal prescribing guidance for udenafil.

Off‑label or expanded uses are not widely documented in UK or EU guidelines; clinicians considering off‑label applications must rely on limited international literature and local governance for unlicensed medicines.

Some markets discuss low‑dose daily regimens, but as of July 2025 this is not an authorised or standard regimen per manufacturer sources.

Definition checklist: Licensed Indication — Erectile dysfunction in Korea and some CIS markets; UK Status — Unlicensed, no MHRA/EMA authorisation as of July 2025.

Clinicians should document rationale and informed consent for any unlicensed use and prefer licensed alternatives where evidence and regulatory approval exist.

Composition And Brand Landscape

Where does udenafil come from and what brand names should UK patients look for?

The active ingredient is udenafil (INN) and the principal brand is Zydena, manufactured by Dong‑A Pharmaceutical in South Korea.

Alternate regional spellings include Zidena in CIS markets and packaging labelled Udenafilo seen in some Spanish/Portuguese online listings.

Formulations commonly sold are tablets of 100 mg and 200 mg in blister packs across Korea, CIS and parts of Asia.

The ATC code for udenafil is G04BE10, placing it in the PDE5 inhibitor class alongside sildenafil and tadalafil.

There are no authorised udenafil brands or generics marketed in the UK or EU as of July 2025.

Common UK PDE5 alternatives available through NHS or private prescription include sildenafil (Viagra), tadalafil (Cialis), vardenafil (Levitra) and avanafil (Spedra).

Supply routes encountered by UK patients include private importation and overseas e‑pharmacies, which can carry risks of relabelling and inconsistent provenance.

When patients present with imported packets, pharmacists should attempt to verify manufacturer details and batch numbers against Dong‑A listings where possible.

Contraindications And Special Precautions

Who should not take udenafil, and what checks must a pharmacist perform?

Absolute contraindications mirror other PDE5 inhibitors: known hypersensitivity to udenafil or excipients and concurrent use with any nitrates owing to the risk of severe hypotension.

Severe hepatic or renal impairment and unstable cardiovascular disease such as recent myocardial infarction, stroke or severe arrhythmia are contraindications or strong reasons to avoid udenafil.

Relative contraindications that require close monitoring include penile anatomical deformities like Peyronie’s disease and conditions that increase priapism risk such as sickle cell disease.

Patients with hypotension at rest, uncontrolled hypertension, bleeding disorders or active peptic ulcer disease should be assessed carefully before any PDE5 inhibitor is considered.

In the UK context pharmacists should assess cardiovascular risk, current medications and document counselling when patients present with imported udenafil.

Advise against combining udenafil with nitrates and instruct patients to seek urgent care for chest pain, severe dizziness or other worrying symptoms.

Report any serious adverse events to the MHRA Yellow Card scheme, particularly when the medicine is imported or unlicensed in the UK.

Dosage Guidelines

How should udenafil be dosed and adjusted for common patient groups?

Manufacturer guidance lists an initial dose of 100 mg taken orally 30–60 minutes before sexual activity, with a maximum single dose of 200 mg and a limit of one dose per 24 hours.

Udenafil is not indicated for individuals under 18 years and should not be used in paediatric populations.

Elderly patients can start at 100 mg and be titrated by tolerance, following the originator labelling.

In renal impairment mild to moderate use with caution and starting low is advised, and severe renal impairment is not recommended due to lack of data.

Hepatic impairment guidance is cautious for mild cases and avoidance for moderate to severe impairment because of insufficient clinical evidence.

Overdose is managed supportively; symptomatic hypotension or priapism require emergency treatment and hospital assessment.

Storage advice for patients: keep below 25°C in the original packaging, protect from moisture and direct sunlight, and transport in secure, temperature‑stable packaging.

Interactions Overview

What medicines and substances must be avoided with udenafil?

The most critical interaction is with nitrates, which together with udenafil can cause severe, life‑threatening hypotension.

Alpha‑blockers carry an additive hypotension risk and require careful timing, dose adjustment and monitoring if combined with a PDE5 inhibitor.

Potent CYP3A4 inhibitors such as ketoconazole or ritonavir can raise udenafil plasma levels and necessitate caution or avoidance, while strong inducers may reduce efficacy.

Alcohol can exacerbate dizziness and hypotensive effects; heavy drinking around dosing is discouraged.

High‑fat meals may delay absorption and onset, similar to other agents in the class, while routine caffeine intake does not have a documented major interaction.

Advise patients to review all medications with a pharmacist or GP before taking imported udenafil and to report interaction‑related adverse events via the MHRA Yellow Card scheme.

Cultural Perceptions And Patient Habits

How do people in the UK typically seek treatment for erectile dysfunction and view imported medicines?

Many patients first consult a GP or local pharmacist when erectile dysfunction becomes a concern, and trusted touchpoints include high‑street pharmacies and NHS online services.

Online forums and patient portals show that UK patients are cautious about importing unlicensed medicines, concerned about authenticity, labelling and aftercare.

Pharmacist counselling is valued for checking interactions and providing reassurance, and many patients prefer licensed alternatives available via NHS or reputable private clinics.

Payment willingness varies regionally; in England the NHS prescription charge influences choices, while in Scotland, Wales and Northern Ireland free prescriptions shift decisions differently.

Typical patient pathways are: NHS → pharmacy → private clinic → online import, with pharmacists often mediating between online purchases and GP verification.

Culturally, shared decision‑making and clinician‑led risk assessment are common expectations among UK patients dealing with erectile dysfunction.

Availability And Pricing Patterns

Where can UK patients legally obtain udenafil and what should they expect to pay?

As of July 2025 Zydena/udenafil is not approved in the EU or UK and is therefore not stocked or prescribed via the NHS; supply in the UK is limited to private import or overseas e‑pharmacies.

Major UK pharmacy chains such as Boots, LloydsPharmacy and Superdrug typically stock licensed PDE5 medicines like sildenafil and tadalafil and do not list Zydena as an authorised product.

NHS prescription charges apply in England (around £9.65 per item as a representative figure), while Scotland, Wales and Northern Ireland have different prescription arrangements that affect patient choices.

Private clinic consultation fees, online pharmacy pricing and import costs vary widely; cheaper unregulated online sources carry a greater risk of poor quality or incorrect labelling.

Electronic prescriptions and registered online pharmacies provide safer access to licensed PDE5 drugs, and clinicians should counsel patients about regulatory and safety trade‑offs if they insist on imported udenafil.

In our online pharmacy, zydena is available without a prescription, with discreet delivery to United Kingdom in 5-14 days.

Comparable Medicines And Preferences

How does udenafil compare to sildenafil, tadalafil, vardenafil and avanafil in everyday practice?

All belong to the PDE5 inhibitor class, with udenafil generally reported to have an onset of about 30–60 minutes and an effective duration cited up to 12 hours.

Sildenafil typically offers fast onset and shorter duration, while tadalafil is known for a longer duration and offers daily dosing options.

Vardenafil and avanafil are other licensed alternatives with variable onset speeds and tolerability profiles valued by prescribers.

Adverse effects are broadly similar across the class: headache, flushing, nasal congestion and dyspepsia are common.

Some reports suggest udenafil may cause fewer transient visual disturbances than sildenafil, but head‑to‑head UK data are limited.

In the UK clinical preference follows MHRA‑licensed options first; udenafil would be considered only as an unlicensed medicine with formal documentation and informed consent.

Frequently Asked Questions

Q1: Is Zydena (udenafil) available on the NHS?

No. As of July 2025 Zydena has no MHRA or EMA marketing authorisation and NHS prescribing is not supported.

Q2: Can I import Zydena or buy it online?

Private import is possible via some e‑pharmacies, but patients should verify manufacturer (Dong‑A), batch details and legal import rules and be aware that unregulated products can carry quality risks.

Q3: How should I take it and what dose?

Manufacturer guidance recommends start 100 mg orally 30–60 minutes before activity, maximum single dose 200 mg and not more than once per 24 hours; adjust for elderly, renal or hepatic disease as advised.

Q4: What should I do if I experience severe side effects?

Seek urgent care for priapism lasting more than four hours or severe hypotension, and report adverse reactions to the MHRA Yellow Card scheme if you are in the UK.

Guidelines For Proper Use

What should a pharmacist cover when counselling a patient about imported udenafil?

Start by verifying medical history, particularly cardiovascular disease and any nitrates or nitrate‑containing medicines.

Review current medications for alpha‑blockers and CYP3A4 modulators and assess priapism risk factors such as sickle cell disease.

Document informed consent and advise patients to seek GP review when an unlicensed medicine is being considered or taken.

Key patient advice includes taking 100 mg 30–60 minutes before sex, avoiding nitrates, limiting alcohol around dosing and not exceeding 200 mg in 24 hours.

Explain emergency signs: chest pain, severe dizziness, sudden vision or hearing changes and priapism require urgent A&E attendance.

Encourage reporting of any adverse events to the MHRA Yellow Card scheme and ensure the GP record notes any off‑label or unlicensed use.

Pharmacists in high‑street chains commonly liaise with GPs for verification and repeat counselling for patients using imported products.

Delivery Across United Kingdom