Revatio (Sildenafil Citrate) – Patient Guide (UK)

Revatio contains sildenafil citrate. It is used to treat certain forms of pulmonary arterial hypertension (PAH) in adults and, in some cases, other patient groups as advised by healthcare professionals. This guide explains what Revatio is, how it works, how it’s taken, key safety information, and practical tips—written for patients using an online pharmacy service in the United Kingdom.

1. Basic product information

Note: Strengths and presentations may differ between products. Always check your specific pack and leaflet for the exact dose and how to take it.

2. How Revatio works (mechanism of action)

Revatio contains sildenafil, a medicine that belongs to a group called PDE5 inhibitors. It works by affecting blood vessels in the lungs.

• Normal pathway: Nitric oxide helps relax smooth muscle in blood vessels by increasing cGMP.
• Role of PDE5: PDE5 breaks down cGMP.
• Effect of sildenafil: Sildenafil inhibits PDE5, helping maintain higher cGMP levels.
• Result: This encourages relaxation of pulmonary blood vessels, which can lower pulmonary artery pressure and improve symptoms in PAH.

Revatio is designed for pulmonary arterial hypertension. It is not the same use as medicines commonly associated with erectile dysfunction, though sildenafil is the same active ingredient. Your local prescribing/clinical guidance will specify the intended condition and dose.

3. Pharmacokinetics (how your body handles the medicine)

Understanding how Revatio moves through the body can help you take it more confidently.

• Absorption: Sildenafil is absorbed through the gut after oral dosing. Peak blood levels generally occur within a few hours.
• Distribution: Sildenafil distributes through the body and binds to plasma proteins.
• Metabolism: It is mainly metabolised by the liver via CYP enzymes (particularly CYP3A4 and also CYP2C9).
• Elimination: Metabolites are excreted primarily in the faeces and, to a lesser extent, in the urine.
• Half-life: The effective duration can last several hours, which is why it can be used on a regular schedule for PAH rather than “as needed.”

Practical meaning: Because sildenafil is processed by the liver and affected by drug interactions, it’s important to review other medicines you take.

4. Typical use in the UK

Revatio is used to treat pulmonary arterial hypertension (PAH). PAH is a condition where the blood vessels in the lungs become narrowed, leading to increased pressure and strain on the heart.

Your clinician may prescribe Revatio as part of a broader treatment plan, sometimes alongside other PAH therapies (for example, endothelin receptor antagonists, prostacyclin pathway therapies, or other strategies). Treatment goals often include:

• Improving exercise capacity
• Reducing symptoms such as breathlessness
• Helping slow disease progression
• Improving quality of life

Important: Revatio is taken regularly for PAH. It is not typically intended for sudden relief of acute breathlessness.

5. When to take Revatio (timing and missed doses)

Follow the dosing schedule given to you with your specific product. Many PAH regimens involve taking doses two or three times a day depending on your individual plan.

How to take it

• Take the tablets with water.
• Try to take your doses at consistent times each day.
• Do not change your dose or stop without medical advice.

If you miss a dose

• Take it when you remember, unless it is close to your next dose.
• If it’s near the next dose, skip the missed dose and continue as normal.
• Do not take a double dose to make up for the missed one.

For ongoing PAH care

PAH treatment often requires regular monitoring (symptoms, clinical review, and sometimes blood tests or specialised assessments). Keep clinic appointments and report side effects promptly.

6. Food interactions and what to expect

In many people, taking sildenafil with food does not meaningfully reduce safety, but it can influence how quickly the medicine starts working.

• With meals: A heavy meal may delay the time to peak effect.
• Practical approach: You can usually take Revatio with or without food—aim for consistency in your usual routine.

Tip: If you notice that your symptoms fluctuate around meal times, discuss timing with your clinician or pharmacist.

7. Alcohol interactions

Alcohol can affect blood pressure and dizziness risk. Because sildenafil can also lower blood pressure in some people, the combination may increase the chance of:

• Dizziness
• Light-headedness
• Headache
• Flushing

Patient-friendly guidance:

• Keep alcohol intake moderate.
• Avoid binge drinking.
• Be cautious if you already have low blood pressure or feel faint.

If you develop fainting, severe dizziness, chest pain, or worsening breathlessness after alcohol, seek urgent medical advice.

8. Medicine interactions (very important)

Certain medicines can significantly increase or decrease sildenafil levels, and some combinations can be dangerous.

Absolute or high-risk interactions

• Nitrates (used for chest pain/angina) and nitrite preparations: the combination can cause a dangerous drop in blood pressure.
• Riociguat (for pulmonary hypertension): combined use is contraindicated due to risk of hypotension.
• “Poppers” (alkyl nitrites): can interact dangerously with PDE5 inhibitors.

Medicines that may increase sildenafil levels

These can increase the likelihood of side effects such as headache, flushing, and low blood pressure:

• Strong CYP3A4 inhibitors (examples include some antifungals and some antibiotics)
• HIV protease inhibitors (examples depend on regimen)

Medicines that may decrease sildenafil levels

These can reduce effectiveness:

• CYP3A4 inducers (certain anti-epileptics and herbal products such as St John’s wort)

Other blood pressure medicines

• If you take medicines that lower blood pressure (including some antihypertensives or alpha-blockers), your prescriber may adjust dosing or monitor you more closely.
• Do not stop any blood pressure medicine without guidance.

Before starting Revatio

• Tell your pharmacist or clinician about all medicines and supplements you use, including herbal products.
• Ensure you understand whether any of your medicines contain nitrates or interact with pulmonary hypertension treatments.

9. Indications (what Revatio is for)

In the UK, Revatio is indicated for the treatment of:

• Pulmonary arterial hypertension (PAH) (to improve exercise capacity and symptoms, as part of appropriate PAH management)

Your healthcare professional may determine suitability based on your PAH type, severity, and overall treatment plan.

10. Dosing (how much to take)

Dosing depends on your condition, age, and other factors such as liver or kidney function and interaction risks. Always follow the dose on your label.

Typical dosing approach (general information)

Revatio is commonly dosed multiple times per day for PAH. The exact dose may vary by:

• Your prescribed strength and regimen
• Whether you have liver impairment
• Whether you take interacting medicines
• Your individual response and tolerance

When dose adjustment may be needed

• Liver impairment: increased sildenafil exposure can occur.
• Kidney impairment: exposure may differ; clinicians may monitor and adjust.
• Drug interactions: if you take medicines that affect metabolism (especially CYP3A4), your clinician may choose a different dosing schedule or avoid certain combinations.

Safety note: Avoid exceeding your prescribed dose. Taking extra doses increases the chance of side effects such as hypotension and vision-related effects.

11. Safety profile (side effects and warnings)

Like all medicines, Revatio can cause side effects. Many are mild and improve over time. However, some symptoms need prompt medical attention.

Common side effects

• Headache
• Flushing (warmth/redness of the skin)
• Indigestion or stomach discomfort
• Nasal congestion (runny or blocked nose)
• Dizziness
• Visual disturbances (e.g., changes in colour perception)

Serious side effects – seek urgent help

Contact urgent medical services or seek emergency care if you experience:

• Chest pain or severe shortness of breath that is worsening
• Fainting or severe dizziness
• Sudden vision loss or sudden hearing loss
• Priapism (painful erection lasting more than a few hours) — this is a medical emergency
• Signs of a serious allergic reaction (swelling of face/lips, difficulty breathing, rash with severe symptoms)

Special cautions

• Low blood pressure: sildenafil may lower blood pressure, which can worsen dizziness.
• Heart conditions: if you have significant cardiovascular disease, discuss suitability and monitoring.
• History of eye problems: PDE5 inhibitors have been associated with rare serious visual events; report changes immediately.
• Bleeding risk: if you take medicines affecting blood clotting, discuss risks.

12. Practical tips for taking Revatio

• Keep a routine: Use reminders (phone alarms) to support regular dosing for PAH.
• Track symptoms: Note changes in breathlessness, fatigue, dizziness, and headaches to discuss at reviews.
• Stand up slowly: If you feel light-headed, change positions gradually.
• Stay hydrated: Dehydration can worsen dizziness and low blood pressure symptoms.
• Avoid interacting products: Do not use nitrates or “poppers.” Avoid St John’s wort unless your prescriber approves it.
• Don’t double up: If you miss a dose, follow the missed-dose guidance and resume your schedule.
• Report vision/hearing changes quickly: Seek immediate help for sudden visual or hearing symptoms.

13. Alternative options (for PAH treatment)

PAH is managed using multiple medication classes and sometimes combination therapy. Alternatives depend on your PAH severity, treatment history, and tolerability.

Other medication classes your clinician may consider

• Endothelin receptor antagonists
• Prostacyclin analogues or receptor agonists
• Soluble guanylate cyclase stimulators (in some cases—note interaction cautions)
• Other PDE5 inhibitors (depending on indication and guidance)
• Supportive therapies such as diuretics or oxygen, where appropriate

Important: Switching between options should be done with clinical guidance to maintain appropriate PAH control and avoid interactions.

14. Market and legal context in the United Kingdom

In the UK, medicines are regulated by the Medicines and Healthcare products Regulatory Agency (MHRA) and dispensed according to medicine classification and pharmacy regulations. PAH treatments such as sildenafil (Revatio) require correct supply and appropriate patient counselling to ensure safe use.

Online pharmacy services in the UK typically aim to provide:

• Clear product information and patient guidance
• Correct identification of the medicine you need
• Checks to reduce the risk of unsafe interactions
• Compliance with applicable UK dispensing and supply requirements

Always read the patient information leaflet supplied with your medicine pack for the most accurate and complete safety information for your specific formulation.

15. Recent guidance and monitoring considerations

Guidance for PAH treatment evolves as new evidence becomes available. In recent years, PAH care has emphasised:

• Early, structured treatment plans based on risk and disease severity
• Care in specialist centres where possible
• Regular monitoring to track symptom response and safety
• Careful management of drug interactions and comorbidities

Your clinician may periodically review your regimen and adjust therapy based on your response and tolerability.

16. Delivery and availability (UK online pharmacy)

Availability can vary by pharmacy and by product presentation (such as tablet strength and pack size). Many online pharmacies in the UK aim to offer:

• Secure delivery options to eligible UK addresses
• Tracking information where available
• Clear dispatch timelines displayed at checkout
• Packaging designed to protect medicines during transit

What to check when ordering:

• Correct product name: Revatio
• Correct strength and pack size
• Any delivery cut-off times
• Household availability for delivery

If an item is out of stock, the pharmacy may provide an expected restock date or an alternative option depending on availability and clinical appropriateness.

17. FAQ about Revatio (Sildenafil Citrate)

Is Revatio the same as sildenafil used for erectile dysfunction?

Revatio and other sildenafil-containing products use the same active ingredient (sildenafil citrate), but they are intended for different conditions and may have different dosing regimens and labels. Always use the product and schedule prescribed for your PAH treatment.

How long does Revatio take to start working?

After a dose, sildenafil can begin working within a few hours. For PAH, improvements are generally assessed over time through symptom and clinical monitoring rather than immediate “as needed” relief.

Can I take Revatio with food?

In many cases, yes. Food may delay peak effect, but it usually does not stop the medicine from working. Taking it consistently at the same times each day can help.

What should I avoid while taking Revatio?

Avoid:

• Nitrates and nitrate-like preparations
• Riociguat
• “Poppers” (alkyl nitrites)
• Unapproved herbal supplements that may interact (such as St John’s wort)

Always check with your pharmacist before starting new medicines or supplements.

Can I drink alcohol?

Alcohol may increase dizziness or low blood pressure symptoms. If you drink, keep it moderate and avoid binge drinking. Stop alcohol and seek medical advice if you feel faint or unwell.

What side effects are most common?

Common side effects include headache, flushing, indigestion, nasal congestion, dizziness, and sometimes visual disturbances.

What if I get a headache or flushing?

These are common and may settle. Stay hydrated and avoid overheating. If headaches are severe, persistent, or you feel faint, contact a healthcare professional for advice.

Can Revatio affect my vision?

Some people experience temporary visual disturbances. Seek urgent medical help if you notice sudden vision loss or severe eye symptoms.

When should I seek urgent help?

Get urgent medical attention if you have severe symptoms such as fainting, severe breathlessness/chest pain, sudden vision or hearing loss, signs of an allergic reaction, or other serious concerns.

How should I store Revatio tablets?

Store according to the instructions on the pack or patient leaflet. In general, keep tablets in their original packaging, away from moisture and excessive heat, and out of the reach of children.

Reminder: This guide provides general information and does not replace the advice in your medicine leaflet or from a healthcare professional. If you have questions about Revatio—especially about interactions—speak to your pharmacist.