Tadasiva (Sildenafil Citrate/Tadalafil): Comprehensive Patient Information – Australia
Basic Product Information
| International Non-proprietary Names (INN) | Sildenafil Citrate, Tadalafil |
|---|---|
| Australian Brand Names | Tadasiva, Viagra, Cialis, Revatio, Adcirca (for pulmonary arterial hypertension) |
| ATC Code | G04BE (Drugs used in erectile dysfunction) |
| Available Forms & Strengths | Oral tablets: typically 100 mg sildenafil / 20 mg tadalafil; other strengths may be available |
| Manufacturers | Several international and Australian pharmaceutical manufacturers; check specific pharmacy for brand |
| Prescription Status in Australia | Prescription Only Medicine (POM) – Schedule 4 (S4) |
Mechanism of Action
- For Patients: Tadasiva contains two active medicines: sildenafil citrate and tadalafil. Both help men get and keep erections by improving blood flow to the penis when you are sexually aroused.
- For Healthcare Professionals: Both act as selective phosphodiesterase type 5 (PDE5) inhibitors, enhancing the nitric oxide-cGMP pathway. Sildenafil has a rapid onset and shorter duration; tadalafil provides a longer-lasting effect (up to 36 hours), due to differences in PDE5 binding and half-lives.
Pharmacokinetics
- Absorption: Tadasiva’s components are rapidly absorbed orally. Sildenafil: Peak plasma in 30–120 minutes; Tadalafil: Peak in 2 hours.
- Metabolism: Both are metabolised in the liver, primarily by CYP3A4 (minor role of CYP2C9 for sildenafil).
- Elimination: Mainly excreted in faeces; less in urine.
- Duration of Action: Sildenafil: 4–6 hours. Tadalafil: up to 36 hours (“the weekend pill”).
Use in Everyday Life & Best Practices (Australia)
- Usually taken “as needed” 30–60 minutes before anticipated sexual activity.
- Do not exceed 1 dose per day.
- Swallow tablets whole with water; do not break or chew.
- Typical starting dose: Sildenafil 50–100 mg, Tadalafil 10–20 mg. Doctor may adjust for effectiveness or side effects.
- Available by prescription from your Australian GP, sexual health specialist, or urologist.
- Discuss use with your partner and doctor if you have heart, liver, or kidney problems.
Dosing: Morning vs Evening
- Morning Use: May offer greater flexibility for weekend or morning intimacy. Tadalafil’s long effect may suit spontaneous encounters.
- Evening Use: Most commonly used for evening or night-time intimacy. If taken soon after a high-fat meal (see below), sildenafil may work less efficiently.
- Take at a consistent time if using daily, as for some tadalafil regimens.
- Discuss the best timing with your doctor to suit your lifestyle and needs.
Taking With Food or on an Empty Stomach: Australian Context
- Sildenafil: Absorption may be delayed and effect possibly reduced after a heavy or fatty meal (e.g., steak and chips, burgers).
- Tadalafil: Less affected by food, but a lighter meal may enhance quicker onset.
- Tip: Traditional Australian meals (meat pies, fish and chips, roast dinners) can be high in fat. Consider taking Tadasiva on an empty stomach or after a light meal for best results.
Interaction Warnings
| Interaction Type | Impact | Advised Action |
|---|---|---|
| Alcohol | Increases risk of side effects; may reduce blood pressure excessively, increase dizziness | Limit alcohol intake; avoid binge drinking |
| Nitrates (e.g., GTN spray, nitroglycerin) | Severe, potentially life-threatening drop in blood pressure | Never use Tadasiva if taking any form of nitrate medication |
| Other antihypertensives | May further lower blood pressure | Monitor blood pressure; discuss with doctor |
| CYP3A4 inhibitors (ketoconazole, ritonavir, etc.) | Increase blood levels of sildenafil/tadalafil—higher risk of side effects | Doctor may recommend dose adjustment or avoidance |
| Grapefruit juice | Raises drug levels; increased risk of side effects | Avoid grapefruit products while using Tadasiva |
Indications: Approved and Off-label Uses
| Indication | Status | Details |
|---|---|---|
| Erectile Dysfunction (ED) | Approved | First-line treatment for ED in adult men |
| Pulmonary Arterial Hypertension (PAH) | Approved for individual substances | Sildenafil (Revatio), Tadalafil (Adcirca) used by specialist prescription |
| Lower Urinary Tract Symptoms / Benign Prostatic Hyperplasia | Off-label for tadalafil; specialist prescription | Under specialist urological supervision only |
Dosing According to Clinical Indications
| Indication | Population | Recommended Dose |
|---|---|---|
| Erectile Dysfunction (ED) | Adult men | Sildenafil 50–100 mg and/or tadalafil 10–20 mg as needed, up to once daily |
| Erectile Dysfunction (ED) | Elderly (65+) | Consider starting at lower dose (sildenafil 25 mg, tadalafil 5 mg); titrate carefully |
| Pulmonary Hypertension (as per specialist) | Adults only | Lower daily doses, regular schedule (sildenafil 20 mg or tadalafil 40 mg) |
| Pediatric | Not indicated for sexual dysfunction | Use only under paediatric specialist direction for PAH |
Safety Profile & Side Effects
| Side Effect | Frequency | Notes |
|---|---|---|
| Headache | Very common | May be relieved with simple analgesics; usually short-lived |
| Flushing (warmth/redness) | Common | Mild, temporary |
| Indigestion (dyspepsia) | Common | Take with water to minimise |
| Nasal congestion | Common | Temporary, generally not serious |
| Dizziness | Common | More likely with alcohol or standing suddenly |
| Visual disturbances (blue tinge, blurred vision) | Uncommon | Usually transient, reversible |
| Priapism (painful, prolonged erection >4 hrs) | Very rare | Seek urgent medical attention |
| Heart attack, stroke | Very rare | Risk increased in those with serious heart disease; seek urgent help for chest pain |
| Hearing loss, ringing in ears | Rare | Discontinue and seek advice if noticed |
Warnings: Do not combine with other ED drugs. Avoid if you have severe heart, liver, or low blood pressure conditions. Discuss with your doctor before use if you have any chronic health problems.
Guidelines for Proper Use (Australian Context)
- Obtain Tadasiva only by prescription from a registered Australian prescriber.
- Purchase from a licensed Australian pharmacy: avoid unregulated online sellers.
- Take only as directed; never more than one dose per 24 hours.
- Inform your GP about all other medicines/supplements you are taking.
- If you experience chest pain, sudden vision or hearing loss, or a prolonged/painful erection, seek immediate medical help (ring 000 or present to a hospital emergency department).
- Store in a cool, dry place below 30oC; keep out of reach of children.
Alternative Treatment Options for Erectile Dysfunction (PBS Reimbursed & Private Medications)
- Viagra (Sildenafil): Available as generic; effective, short-acting; may be affected by food.
- Cialis (Tadalafil): Long-acting; option for daily dosing; less affected by meals.
- Levitra (Vardenafil): Similar to sildenafil; onset and side effects profile slightly different.
- Avanafil (not PBS listed): Faster onset; less interaction with food.
- Vacuum erection devices: Non-pharmaceutical, can be considered if oral agents unsuitable.
- Testosterone replacement: For men with documented low testosterone only, under endocrinologist supervision.
- Injection therapies (alprostadil): Used when oral medications are ineffective or unsuitable.
- Discuss PBS eligibility and the best options with your Australian doctor. Most oral drugs are prescription-only and some (not all) are government reimbursed for specific indications on the PBS (Pharmaceutical Benefits Scheme).
Legal, Registration, and Reimbursement Status in Australia
- Tadasiva is considered a combination product of two registered and approved drugs in Australia (sildenafil, tadalafil).
- Therapeutic Goods Administration (TGA) regulates approval, quality, and safety in Australia.
- Prescription-only (S4); not for over-the-counter sale.
- Some individual PDE5 inhibitors are PBS listed for select severe cases of ED (e.g., after prostate surgery); most are private scripts.
- Reimbursement through PBS is under strict criteria; discuss eligibility with your healthcare provider.
Latest Research and Clinical Guidance (2022–2025)
- Combination PDE5 inhibitor therapy (sildenafil + tadalafil) is not widely standard due to increased risk of side effects, but may be considered for select refractory cases under specialist supervision (Wong et al, Asian Journal of Andrology 2023).
- Australian and international guidelines (Urological Society of Australia and New Zealand, AUA, EAU) recommend monotherapy as first-line, with combination regimens reserved for special cases.
- Regular cardiovascular screening recommended prior to and during use. (Australian Government Health Advisory, 2023).
- Emerging real-world data emphasise discussing patient/partner preferences, side effect risk, and realistic expectations.
Availability and Delivery (Australia, 2024)
| Pack Size | Indicative Price Range (AUD) | Online/Home Delivery Times |
|---|---|---|
| 4 tablets | $40–$70 | Capital cities: 1–2 business days; Regional: 2–4 days |
| 8 tablets | $75–$135 | As above |
| 16 tablets | $140–$260 | As above |
Note: Prices are indicative for private prescriptions and will vary; ask your pharmacy for updates. Express and discreet packaging options are generally available.
Frequently Asked Questions (FAQ)
- Do I need a prescription for Tadasiva?
Yes. In Australia, Tadasiva and all PDE5 inhibitor combinations require a valid prescription from a licensed healthcare provider. - Can I drink alcohol when using Tadasiva?
Small amounts of alcohol are unlikely to interfere, but drinking heavily can increase side effects such as dizziness or low blood pressure. It is best to limit alcohol. - Can Tadasiva be used with heart medications?
Never combine Tadasiva with any nitrate medications or amyl nitrite (“poppers”) as this is dangerous. Other heart medications may interact—always ask your doctor or pharmacist first. - Is it safe and legal to buy Tadasiva online?
Only purchase from registered Australian pharmacies or telehealth services. Avoid overseas or unregulated websites due to risk of counterfeit products. - What should I do if I experience side effects?
For common side effects like mild headaches or flushing, rest and simple pain relief may help. For severe symptoms (e.g., chest pain, prolonged erections, vision loss), seek immediate medical help (call 000 if needed).
For personalised advice or concerns about Tadasiva, always consult your Australian healthcare professional or pharmacist.

