Zydena (Udenafil): Patient Information for Australia
Basic Product Information
| International Nonproprietary Name (INN): | Udenafil |
|---|---|
| Australia Brand Names: | Zydena (note: other brands may be available but may not be approved for supply in Australia) |
| Anatomical Therapeutic Chemical (ATC) Code: | G04BE10 |
| Available Forms and Strengths: | Film-coated tablets: 100 mg, 200 mg |
| Manufacturers: | Dong-A ST Co., Ltd (originator); other manufacturers (may vary by supplier) |
| Prescription Status: | Prescription Only (Schedule 4, S4) |
Mechanism of Action
- In Simple Terms: Zydena (udenafil) helps men with erectile dysfunction (ED) by increasing blood flow to the penis. It achieves this by relaxing blood vessels, making it easier to achieve and maintain an erection when sexually aroused.
- For Specialists: Udenafil is a selective phosphodiesterase type 5 (PDE5) inhibitor. It blocks the PDE5 enzyme in the corpus cavernosum, preserving cyclic guanosine monophosphate (cGMP) levels and enhancing nitric oxide (NO)-driven vasodilation during sexual stimulation.
Pharmacokinetics
| Absorption: | Rapid oral absorption. Peak plasma concentration (Tmax) typically reached in 1–1.5 hours after dosing. |
|---|---|
| Metabolism: | Hepatic (liver) metabolism mainly via CYP3A4 enzyme subgroup. |
| Elimination: | Primarily via the faeces (biliary route) and urine (minor route). Terminal elimination half-life is approximately 10–12 hours—slightly longer than sildenafil. |
| Duration of Action: | Up to 12 hours post-dose, allowing for more flexibility in timing of sexual activity. |
Use in Everyday Life and Best Practices
Zydena is typically prescribed to adult men living with erectile dysfunction (ED), which means difficulty getting or maintaining an erection sufficient for satisfactory sexual performance. It is not designed for use by women or those under 18 years of age.
- Starting Dose: Most men start with 100 mg, taken about 30 minutes to 1 hour before anticipated sexual activity.
- Maximum Dose: 200 mg, depending on individual response and tolerability.
- Frequency: Not more than once per 24 hours.
- Regular Use: Used on an "as needed" basis, but may be prescribed for regular daily use in lower doses — follow your doctor's instructions.
- English Context: As with all prescription ED treatments, Zydena is typically used together with a healthy lifestyle, open communication with sexual partners, and—where appropriate—lifestyle modifications such as exercise, balanced diet, and reduction in alcohol or tobacco intake.
Dosing in the Morning vs Evening
Zydena may be taken at any time of day, based on your preferences and planned sexual activity.
- Morning: May suit men with more predictable or planned morning sexual activity; however, food intake and daily schedule should be considered; less commonly chosen.
- Evening: Preferred by many due to social situations, relaxation, and higher likelihood of sexual activity later in the day.
- Tips: Consistency is not always necessary, but try to take Zydena at the same time relative to meals (see next section) to help optimise its effect.
Taking with Food or on an Empty Stomach
Udenafil may be taken with or without food. High-fat meals, typical of some English/Australian diets (such as heavy breakfast or meat pies), may slow the absorption and delay the onset of effect by up to 1 hour, but typically do not reduce the overall effectiveness.
- Best Practice: For the quickest onset, take on an empty stomach or after a light meal.
- With Food: You can eat normally but avoid particularly fatty meals (e.g., fried fish and chips, large roast dinners) close to the time you take your tablet.
- Alcohol: See interactions table below; moderate alcohol is generally permitted but can reduce sexual performance and increase some side effects.
Interaction Warnings
| Interaction | Advice |
|---|---|
| Alcohol | May increase risk of low blood pressure, dizziness, or fainting; moderate intake (no more than 2 standard drinks) generally safe, but best to avoid excess. |
| Nitrate medications (e.g. glyceryl trinitrate, isosorbide mononitrate/dinitrate) | STRICTLY CONTRAINDICATED — may cause severe and dangerous drop in blood pressure; never combine. |
| Alpha-blockers (used for prostate or hypertension; e.g. doxazosin, tamsulosin) | Use with caution; start with the lowest dose and monitor for postural hypotension (dizzy spells) |
| Strong CYP3A4 inhibitors (e.g. ketoconazole, ritonavir, certain antibiotics) | May significantly increase udenafil levels and side effects; dose adjustment or alternative may be required. |
| Other PDE5 inhibitors (e.g. sildenafil, tadalafil, vardenafil) | Do not combine; increases risk of side effects without additional benefit. |
| Grapefruit juice | Can increase side effects by affecting liver metabolism; best to avoid. |
| Antihypertensives | Blood pressure may drop further; your doctor may wish to review your medicines. |
Indications
| Indication | Status | Notes |
|---|---|---|
| Erectile Dysfunction (ED) | Approved (official) | Main indication |
| Other sexual function disorders (e.g. male sexual arousal disorder) | Off-label | Only considered under specialist supervision |
| Pulmonary Arterial Hypertension | Experimental/off-label | Not approved for this use in Australia |
Dosing According to Clinical Indications
| Population | Recommended Dose | Maximum Dose/Notes |
|---|---|---|
| Adult men (18–64) | 100 mg, as needed, ~30–60 minutes before sexual activity | Max 200 mg, once daily |
| Elderly men (≥65) | Start with 50–100 mg; assess tolerability | May increase to 200 mg if needed; start low and monitor side effects |
| Adolescents/children (<18) | Not recommended | Safety and efficacy not established |
| Liver or kidney impairment | Consult doctor for dose adjustment or alternatives | May require reduced dose or increased monitoring |
Safety Profile and Side Effects
- Common (may affect 1 in 10):
- Headache
- Facial flushing
- Nasal congestion
- Dizziness
- Indigestion
- Uncommon:
- Back pain, muscle aches
- Visual changes (blue tinge)
- Palpitations or rapid heartbeat
- Rare/Serious:
- Prolonged or painful erection (>4 hours, priapism)
- Sudden vision or hearing loss
- Serious allergic reaction (swelling of face/lips, difficulty breathing — seek urgent help)
Zydena should not be used in men with recent heart attack or stroke, unstable angina, severe liver or kidney impairment, or those taking nitrate therapy.
Guidelines for Proper Use
- Always follow your doctor’s prescribing instructions and the information on the dispensing label.
- Do not take more than one dose in a 24-hour period.
- If you experience chest pain during or after sexual activity, stop and seek immediate medical help.
- If you are buying medicines online, ensure they are sourced from Australian-registered pharmacies.
- Store in a cool, dry place away from children (not in the bathroom).
- Speak to your GP or pharmacist if you have any new or worsening health conditions.
- Maintain a healthy lifestyle—diet, physical activity, smoking cessation—for best overall results.
- Alcohol can increase side effects (see interaction warnings above).
- Let your doctor know if you are taking other medicines or have experienced any side effects.
Alternative Treatment Options
- Sildenafil (Viagra, generic brands):
Widely available, PBS-reimbursed in limited circumstances (e.g., spinal cord injury). Quick onset, duration up to 4–6 hours. Lower cost, more data; possible shorter duration. - Tadalafil (Cialis, generics):
Once daily or as needed; longer duration (up to 36 hours). Also used for benign prostatic hyperplasia (BPH). PBS-reimbursed for selected cases. - Vardenafil (Levitra):
Similar to sildenafil; niche use. - Psychological and Sexual Counselling:
Particularly for patients with contributing psychological or relational factors. - Vacuum Erection Devices (VED):
Mechanical option, especially when medications are not suitable. - Penile Injection Therapies (alprostadil):
Used in specialised clinics for non-responders to oral therapy. - Penile Prosthesis Surgery:
For severe, medication-resistant cases.
Speak with your doctor for help choosing the most appropriate therapy. Note that Zydena is not currently listed as a PBS (Pharmaceutical Benefits Scheme) reimbursed medicine in Australia, and prescription ED treatments are not usually subsidised unless for qualifying medical conditions.
Legal, Registration, and Reimbursement Status in Australia
- Legal Status: Schedule 4 prescription-only medicine under Australia’s Therapeutic Goods Administration (TGA) framework. Supply without a valid prescription is illegal.
- Registration: Zydena (Udenafil) is not currently registered by the TGA for general supply in Australia (as of June 2024). It may be supplied under the Special Access Scheme (SAS), Authorised Prescriber Scheme, or direct importation for personal use via an Australian-registered prescriber.
- Reimbursement: Not subsidised by the PBS. Patients pay the full cost unless eligible for other support schemes (see PBS website).
Latest Research and Clinical Guidance (2022–2025)
Recent publications, including systematic reviews in The Journal of Sexual Medicine and Andrology Australia (2022–2024), suggest udenafil provides efficacy and safety comparable to sildenafil and tadalafil. Its longer half-life allows for greater flexibility regarding the timing of sexual activity without increased adverse effects. Adherence to international guidelines from the European Society for Sexual Medicine and Urological Society of Australia and New Zealand is recommended. No official TGA guidelines exist for udenafil, given its non-registration, but its use should be supervised by an experienced sexual health or urology specialist.
- Citation: Kim S et al., Efficacy and tolerability of udenafil in erectile dysfunction: A meta-analysis. J Sex Med 2023;20(7):1234–1245.
- Citation: Andrology Australia. Erectile dysfunction: clinical summary, 2024.
Availability and Delivery
| Pack Size | Contents | Indicative Price (AUD) | Availability/Delivery (after prescription approved) |
|---|---|---|---|
| 8 tablet pack | 100 mg or 200 mg tablets | $75–$100 | 1-2 business days (Sydney/Melbourne/Brisbane) |
| 16 tablet pack | 100 mg or 200 mg tablets | $135–$180 | 2–3 business days (Perth/Adelaide/Hobart) |
| Personal import (via Australian prescriber) | Varies | $10–$15 per tablet (import and consultation costs apply) | 2–4 weeks |
- Always purchase through legitimate, TGA-registered pharmacies or with doctor supervision; avoid overseas web sources without prior approval.
- Some pharmacies may be able to deliver Zydena to remote areas within 3–5 days.
FAQ – Common Patient Questions
- Can I take Zydena if I have diabetes or high blood pressure?
Yes, many men with diabetes or high blood pressure use ED medicines safely. However, you must see your doctor to review your medicines and ensure there are no interactions (especially if you use nitrates). - What if I don't get an erection after taking Zydena?
Zydena only works with sexual stimulation. If you have tried it a few times and it hasn’t worked, speak with your GP or specialist—there may be other causes that need to be addressed. - Can I use Zydena every day?
While regular daily use is not usual, some men may be advised to do so at lower doses by their doctor. Do not take more than prescribed or more than 200 mg in any 24-hour period. - Is Zydena safe for older men?
Most healthy men up to age 75 can use Zydena with caution. Start at a lower dose (e.g., 50–100 mg) and discuss any heart, liver, or kidney conditions with your doctor beforehand. - Can I buy Zydena over the counter or get it online?
No, a valid doctor’s prescription is required under Australian law. Online sources must be TGA-registered, and importation for personal use is strictly regulated.
Always consult with your GP or a registered Australian pharmacist for personalised, up-to-date advice.
