Revatio (Sildenafil Citrate) – Patient Information (Australia)

Revatio is a medicine containing sildenafil citrate. It is used to treat certain types of pulmonary hypertension (high blood pressure in the lungs). This page explains how Revatio works, how it is taken, what to expect, and important safety information—written in patient-friendly language for people in Australia.

Always follow the advice provided by your treating healthcare professional and the directions on your medicine label.

1. Basic product information

In Australia, availability and pack strengths can vary. Your pharmacist or supplier can confirm the exact presentation you are purchasing.

2. What Revatio is used for (indications)

Revatio is used for pulmonary arterial hypertension (PAH) to help improve symptoms and exercise capacity. PAH involves narrowed or stiff arteries in the lungs, raising pressure and making it harder for the heart to pump blood through the lungs.

Revatio may be used:

• As monotherapy (alone), or
• In combination with other PAH medicines (for example, therapies targeting different pathways).

Your treating clinician will determine whether Revatio is appropriate for your specific type of pulmonary hypertension.

3. How Revatio works (mechanism of action)

Sildenafil belongs to a group of medicines called PDE5 inhibitors (phosphodiesterase type 5 inhibitors).

In pulmonary arteries, sildenafil helps increase levels of a natural signalling molecule called nitric oxide (through the nitric oxide–cGMP pathway). This results in:

• Relaxation of smooth muscle in the blood vessel wall
• Widening (dilation) of pulmonary blood vessels
• Lower resistance to blood flow through the lungs

The overall effect is to reduce pulmonary pressure and improve symptoms related to PAH.

4. Pharmacokinetics (how the body handles Revatio)

Understanding pharmacokinetics can help explain timing and how factors like food or other medicines may affect you.

• Absorption: Sildenafil is absorbed after oral administration. Peak blood levels typically occur within a few hours (commonly around 1–2 hours for many patients, though it can vary).
• Distribution: Sildenafil distributes throughout the body and binds to plasma proteins.
• Metabolism: The liver mainly metabolises sildenafil via the CYP450 enzyme system (particularly CYP3A4).
• Elimination: Metabolites are cleared primarily via the liver/bile and to a lesser extent via the kidneys. The overall duration of effect is reflected in how often it is taken for PAH.

Because sildenafil is processed by liver enzymes, medicines that strongly affect these pathways can change sildenafil levels in the body.

5. Typical dosing and timing

Dosing for Revatio in PAH is individualised based on your condition, response, and other medications. Common PAH dosing regimens use multiple daily doses rather than once-daily dosing used in some other sildenafil indications.

Important: Your healthcare professional will specify the exact dose and schedule. Do not change your dose without medical advice.

How to take Revatio

• Take tablets as directed at regular times.
• Try to keep doses consistent each day to maintain stable blood levels.
• If you miss a dose, follow the instructions you were given by your clinician or pharmacist. In general, do not take extra doses to “catch up” unless advised.

When you may notice effects

• Some people notice improvement in symptoms over days.
• More meaningful clinical benefits can take longer, and follow-up assessments are often used to judge response.
• If you feel worse rather than better, seek medical advice promptly.

6. Food interactions (including what to eat)

Food can affect the timing and speed of sildenafil absorption. In many cases, sildenafil can be taken with or without food, but for some people a heavy or high-fat meal may delay absorption and slightly delay onset.

• With food: Absorption may be slower, meaning you may feel effects later.
• Fasting: Absorption may occur faster.

To keep your schedule consistent, consider taking Revatio at the same times relative to meals each day unless your clinician advises otherwise.

7. Alcohol interactions

Alcohol may increase the risk of dizziness or low blood pressure when combined with sildenafil, because both can contribute to changes in blood vessel tone and circulation.

• Limit alcohol where possible, especially at the start of treatment.
• Avoid binge drinking.
• If you experience lightheadedness, fainting, or unusual headaches, speak to a clinician.

8. Interactions with other medicines

Interactions are important with sildenafil. Some medicines can increase sildenafil levels and raise the risk of side effects, while others can reduce effectiveness.

Medicines that can be dangerous to combine

Sildenafil should generally not be used with nitrates (for example, glyceryl trinitrate) or nitric-oxide donors, because the combination can cause a marked drop in blood pressure.

Also avoid combining with riociguat (a soluble guanylate cyclase stimulator) due to risk of significant blood pressure effects.

Medicines that may increase sildenafil levels

Sildenafil is metabolised by CYP3A4. Medicines that strongly inhibit CYP3A4 can raise sildenafil concentrations. Examples (not exhaustive) include:

• Some antifungal medicines (e.g., ketoconazole, itraconazole)
• Some antibiotics (e.g., clarithromycin)
• Some HIV medications (certain protease inhibitors)
• Some “azole” antifungals and other strong CYP3A4 inhibitors

Combining these may increase the likelihood of adverse effects such as headache, flushing, or visual disturbances.

Medicines that may reduce sildenafil levels

CYP3A4 inducers can reduce sildenafil concentrations and effectiveness. Examples include some medicines used for:

• Seizures (certain anticonvulsants)
• Tuberculosis (some TB medicines)
• Other strong inducers

Blood pressure and prostate (“alpha-blocker”) medicines

If you take medicines that affect blood pressure—such as alpha-blockers for urinary symptoms—there can be an additive blood pressure-lowering effect. Your clinician may adjust dosing schedules and monitor you more closely.

Riociguat, nitrates, and emergency angina treatment

If you have angina and use nitrate medicines for emergency relief, you must discuss this with your healthcare team before using sildenafil. In an emergency, tell paramedics or clinicians that you take Revatio so they can manage blood pressure safely.

Always tell your pharmacist or doctor about all medicines you take (including over-the-counter products, herbal supplements, and recreational substances).

9. Safety profile and side effects

Like all medicines, Revatio can cause side effects. Not everyone will experience them. Many side effects are mild and temporary, but some require urgent medical attention.

Common side effects

• Headache
• Flushing (warmth/redness of the skin)
• Indigestion or stomach discomfort
• Dizziness
• Nasal congestion
• Visual disturbances (e.g., mild colour tinge or blurred vision), which are less common but recognised with PDE5 inhibitors

Less common but serious effects – seek urgent help

• Sudden vision loss or severe eye symptoms
• Sudden hearing loss
• Chest pain or fainting
• Severe allergic reaction (swelling of face/lips, rash, breathing difficulty)
• Priapism (a prolonged painful erection lasting more than 4 hours) – this requires emergency treatment
• Severe dizziness or collapse due to low blood pressure

When to contact a clinician promptly

• Side effects that are persistent or worsening
• Signs of worsening PAH symptoms (e.g., increasing shortness of breath, swelling, or reduced exercise tolerance)
• Any new symptoms after starting or changing dose

If you are unsure whether symptoms are serious, it’s safer to seek medical advice promptly.

10. Practical use tips (getting the best from Revatio)

• Take it consistently: Use a daily routine (e.g., with morning and evening activities) to reduce missed doses.
• Track your symptoms: Note changes in breathlessness, fatigue, and exercise tolerance to help your clinician assess response.
• Monitor blood pressure if advised: Some people may experience dizziness or lightheadedness—especially when starting treatment or if taking other blood pressure medicines.
• Be cautious with activities that require alertness: If you feel dizzy, avoid driving or hazardous tasks until you know how the medicine affects you.
• Avoid unapproved supplements: Herbal products and “performance” supplements can interact with PDE5 inhibitors.

What to do if you miss a dose

If you miss a dose, take it when you remember unless it’s close to your next dose. Do not double up to make up for a missed dose. If you’re unsure, ask your pharmacist.

11. Alternative options for PAH (discuss with your clinician)

Pulmonary arterial hypertension can be treated with multiple medication classes. Depending on your diagnosis, severity, and response, alternatives may include:

• Other PDE5 inhibitors (sildenafil is one option; treatment plans may vary)
• Endothelin receptor antagonists
• Soluble guanylate cyclase stimulators
• Prostacyclin pathway therapies (e.g., prostacyclin analogues or prostacyclin receptor agonists)
• Combination therapy using two or more pathways

The best alternative depends on factors such as your functional class, symptoms, liver/kidney function, and co-existing medicines. Your clinician can explain the rationale for choosing Revatio versus other options.

12. Market and legal context for Australia (what this means for you)

In Australia, medicines are supplied under a structured regulatory framework. Whether a medicine can be purchased and how it is supplied depends on classification and prescribing rules.

For PAH treatment, Revatio is typically managed under appropriate clinician oversight and medicine supply pathways. When ordering online, ensure that:

• You select a reputable Australian pharmacy website.
• The product you receive matches the correct strength and form.
• Your order includes the correct directions and consumer medicine information.
• You provide accurate medical details if the pharmacy asks for them (to help screen for interactions and suitability).

Australia also has requirements for safe dispensing and product authenticity, including controls around importation and distribution. Choose services that clearly state where they source products and how they handle quality and delivery.

Note: If you have questions about whether Revatio is appropriate for you, speak with a healthcare professional or pharmacist.

13. Recent guidance and clinical monitoring (general points)

Clinical guidance for PAH management evolves over time. Your clinician may recommend monitoring based on your response to therapy and overall health status. Typical monitoring may include:

• Assessment of symptoms and functional capacity
• Regular review of side effects and medication interactions
• Periodic measurements such as oxygen saturation and relevant PAH tests as appropriate
• Review of liver function if clinically indicated (since sildenafil is metabolised by the liver)

If you become pregnant, develop liver disease, or start or stop other medicines, tell your clinician promptly so your regimen can be reviewed.

14. Delivery and availability in Australia

Online pharmacies may deliver Revatio to eligible Australian addresses. Delivery times depend on stock availability, courier services, and your location.

When ordering, consider the following:

• Stock status: Some strengths or formulations may sell out temporarily.
• Packaging and labelling: Check for original manufacturer packaging and clear labelling.
• Cold-chain needs: Sildenafil tablets typically do not require refrigeration unless otherwise stated.
• Delivery reliability: Choose a pharmacy that provides tracking and clear delivery estimates.

If you are travelling or plan to start treatment soon, allow extra time for dispatch and delivery.

15. Frequently Asked Questions (FAQ)

Is Revatio the same as Viagra?

Both contain sildenafil citrate, but they are used for different conditions and may have different dosing schedules and formulations depending on the product and country. Always use Revatio as directed for your PAH treatment plan.

How quickly does Revatio start working?

Sildenafil is absorbed relatively quickly and reaches peak blood levels within a few hours for many people. Symptom improvement can vary; some people notice changes early, while others may take longer. Clinical benefits are usually judged over time with follow-up.

Can I take Revatio with food?

Yes, Revatio can generally be taken with or without food. A heavy meal may delay absorption, so consistent timing relative to meals can help you manage predictable effects.

What should I do if I get a headache or flushing?

Headache and flushing are common sildenafil effects. Hydration, rest, and taking the medicine at the same times daily may help. If side effects are severe, persistent, or you feel faint, contact a clinician or pharmacist.

Can I drink alcohol while taking Revatio?

Alcohol may increase dizziness or blood pressure-related side effects. Keep alcohol modest, avoid binge drinking, and seek advice if you experience lightheadedness or fainting.

Are there medicines I must avoid?

Yes. Do not combine sildenafil with nitrates or riociguat due to risk of significant blood pressure effects. Also discuss any strong antifungals, antibiotics, or HIV medicines with your pharmacist due to possible interaction with sildenafil metabolism.

What if I feel my breathing is worsening?

Worsening shortness of breath or exercise tolerance may indicate disease progression or another issue. Seek prompt medical advice rather than adjusting your dose without guidance.

Can Revatio affect vision?

Some people experience mild visual changes. Sudden or severe vision loss is a medical emergency and needs urgent assessment. If you notice unusual eye symptoms, seek advice promptly.

Is Revatio safe for everyone?

Revatio may not be appropriate for everyone, particularly people with certain heart conditions, low blood pressure, severe liver impairment, or those taking interacting medicines. A pharmacist or clinician can help review suitability.

16. Summary

Revatio (sildenafil citrate) helps treat pulmonary arterial hypertension by relaxing blood vessels in the lungs through the PDE5/ nitric oxide–cGMP pathway. It is typically taken in a structured daily schedule, and consistent timing matters for best day-to-day control.

• Be mindful of interactions, especially nitrates and riociguat.
• Watch for dizziness, headache, and other common effects.
• Seek urgent help for serious symptoms such as priapism, sudden vision or hearing loss, or severe allergic reactions.
• Maintain regular monitoring and review your medicines with a clinician.

If you’d like, tell us the strength and form you’ve been given (tablet strength and daily schedule) and any other medicines you take—then we can help you identify practical interaction questions to discuss with your pharmacist.