Revatio (Sildenafil Citrate) – Patient Guide (UK)

Revatio is a medicine containing sildenafil citrate. In the UK, it is used to treat a specific condition affecting the heart and lungs called pulmonary arterial hypertension (PAH). This page explains how Revatio works, how it is typically taken, what to expect, and important safety information. It is written to be easy to follow and patient-friendly.

Quick overview

• Active ingredient: Sildenafil citrate
• Brand name: Revatio
• Used for: Pulmonary arterial hypertension (PAH)
• How it works: Helps relax blood vessels in the lungs
• Common dosage form: Tablets (strengths vary by product pack)
• Key caution: Do not use with nitrates (e.g., glyceryl trinitrate) or “poppers”

What is pulmonary arterial hypertension (PAH)?

Pulmonary arterial hypertension is a condition where the blood pressure in the arteries of the lungs becomes abnormally high. This puts strain on the heart and can make everyday activities harder. Symptoms may include:

• Shortness of breath (especially on exertion)
• Fatigue
• Chest discomfort
• Dizziness
• Swelling of the ankles/legs (in advanced cases)

Revatio helps lower the pressure in the lung arteries, improving blood flow and symptoms for many people.

How Revatio works (mechanism of action)

Revatio contains sildenafil, which belongs to a group of medicines called PDE5 inhibitors (phosphodiesterase type 5 inhibitors).

In PAH, blood vessels in the lungs can become narrow and less able to relax. Sildenafil works by:

• Blocking PDE5, an enzyme that breaks down cGMP
• Increasing cGMP levels in the smooth muscle cells lining blood vessels
• Allowing blood vessels to relax and widen
• Reducing pulmonary vascular resistance (the resistance to blood flow in the lungs)

With improved blood flow, the heart has less resistance to pump against.

Pharmacokinetics (how the body handles Revatio)

Pharmacokinetics describes what the body does to a medicine—how it is absorbed, distributed, metabolised, and eliminated.

• Absorption: Sildenafil is absorbed after taking a dose. Peak effects occur after it reaches maximum concentration in the bloodstream.
• Onset: Some people notice effects within about an hour, though the overall benefit in PAH may build with ongoing treatment.
• Metabolism: Sildenafil is mainly broken down in the liver by enzymes, particularly CYP3A4.
• Elimination: Metabolites are mainly removed through the liver and kidneys.
• Duration: The effect lasts for several hours; however, PAH treatment typically requires regular dosing rather than “as needed” use.

Note: Your prescriber may adjust the dose based on other medicines, liver function, kidney function, age, and your overall clinical situation.

Indications (when Revatio is used)

In the UK, Revatio (sildenafil citrate) is indicated for the treatment of:

• Pulmonary arterial hypertension (PAH) in adults (and in some cases, depending on the specific product licence and local guidance, use may extend to certain paediatric populations under specialist care).

Revatio may be used alone or as part of combination therapy in PAH, depending on severity and response.

Typical use and treatment goals

Revatio is intended for long-term management of PAH. While individual responses vary, treatment aims to:

• Improve symptoms such as breathlessness and exercise tolerance
• Lower lung artery pressure
• Slow disease progression and improve quality of life
• Support overall cardiovascular health in PAH

Important: Revatio is not a “rescue” medication for sudden attacks of breathlessness. It is part of a planned regimen.

How to take Revatio (dosing and timing)

Because PAH affects people differently, dosing should follow the directions provided with your medicine. Dosing details can vary by the specific licensed formulation and strength.

Common principles (general guidance):

• Take it regularly rather than only when symptoms worsen.
• Try to take doses at the same times each day to maintain steady effect.
• Do not stop Revatio suddenly unless advised—PAH can worsen without ongoing treatment.

Timing: In many PAH regimens, sildenafil is taken multiple times per day. The exact schedule depends on your prescription instructions and product licence. If you are unsure about your schedule, check the pack and seek clarification from your healthcare team.

Food interactions (with meals)

Food is not usually a major issue with sildenafil. In many cases, it can be taken with or without food. However, individual absorption and tolerability may vary.

• If you notice stomach discomfort, try taking Revatio with a light meal.
• If you experience headache or flushing, spacing doses and staying hydrated may help.

Tip: If you take other medicines at set meal times, keep Revatio consistent with your routine. Consistency helps maintain predictable blood levels.

Alcohol interactions

Alcohol can widen blood vessels and may affect blood pressure. Sildenafil can also lower blood pressure. Together, they may increase the likelihood of:

• Dizziness
• Lightheadedness
• Low blood pressure symptoms (especially when standing)

Moderation is advised. If you feel unwell after combining alcohol and Revatio, avoid alcohol and speak to a clinician.

Important medicine interactions

Certain medicines can strongly interact with sildenafil. Some interactions can be dangerous, while others require dose adjustments and careful monitoring.

Do not use with nitrates or “poppers”

• Nitrates (e.g., glyceryl trinitrate, isosorbide dinitrate/mononitrate) can cause a significant drop in blood pressure when combined with sildenafil.
• “Poppers” (alkyl nitrites) should not be used with sildenafil.

Be cautious with blood pressure–lowering medicines

• Medicines for blood pressure or other vasodilators may further lower blood pressure when combined with Revatio.
• Monitor for symptoms such as dizziness, fainting, or unusual weakness.

CYP3A4 inhibitors (can increase sildenafil levels)

Sildenafil is metabolised mainly by CYP3A4. Medicines that inhibit CYP3A4 can increase sildenafil exposure and side effects.

• Examples can include certain antifungals (e.g., ketoconazole), macrolide antibiotics (e.g., clarithromycin), and some HIV protease inhibitors.
• If you take these, your dose may need adjustment and you may require extra monitoring.

CYP3A4 inducers (can reduce sildenafil levels)

Some medicines speed up metabolism and may reduce sildenafil effectiveness.

• Examples can include rifampicin and certain anticonvulsants.

Other PAH medicines

Revatio may be used alongside other PAH therapies in specialist care (for example, endothilin receptor antagonists or prostacyclin-based therapies). Combining therapies should be guided by specialists because blood pressure and overall effects need monitoring.

Alpha-blockers

If you take an alpha-blocker for urinary symptoms or blood pressure, the combination can increase risk of low blood pressure in some people. Dose timing and gradual changes may be needed.

Safety profile and side effects

Like all medicines, Revatio can cause side effects. Many people experience mild or temporary effects, while others may require medical advice.

Common side effects

• Headache
• Flushing (warmth/redness)
• Indigestion or stomach discomfort
• Nasal congestion
• Visual changes (e.g., altered colour perception) – typically temporary

Less common but important side effects

• Back pain
• Dizziness
• Low blood pressure symptoms
• Nausea

Seek urgent medical help if you experience

• Chest pain, severe shortness of breath, or fainting
• Sudden vision loss or severe eye pain
• Sudden hearing loss or ringing in the ears
• A serious allergic reaction such as swelling of the face/lips or difficulty breathing
• Prolonged erection (painful or lasting longer than expected) – emergency assessment is required

Practical note: Report any persistent or worrying side effects to your healthcare team. Your dose or regimen may need review.

Practical tips for using Revatio effectively

• Keep a routine: Taking doses at consistent times can help maintain stable symptom control.
• Don’t double up: If you miss a dose, follow the advice given with your medicine or by your healthcare team. Do not take extra doses to “catch up” unless instructed.
• Hydrate sensibly: Dehydration can worsen dizziness. Aim for normal fluid intake unless you’ve been advised to restrict fluids.
• Monitor symptoms: Track breathlessness, exercise tolerance, swelling, and how you feel overall. This helps healthcare teams assess response.
• Be careful with recreational substances: Avoid drugs that contain nitrates or “poppers.”
• Plan travel: Carry your medicine with you in hand luggage when travelling, and keep doses on schedule.
• Driving and machinery: If you feel dizzy or lightheaded, avoid driving or operating machinery.

Alternative treatment options

PAH management may include different classes of medicines, sometimes in combination. Alternatives to Revatio (sildenafil) include:

• Tadalafil (another PDE5 inhibitor, longer acting)
• Endothelin receptor antagonists (e.g., bosentan, ambrisentan)
• Soluble guanylate cyclase stimulators (e.g., riociguat) – note this class must not be used with certain other vasodilators
• Prostacyclin analogues or prostacyclin receptor agonists
• Supportive measures (e.g., oxygen where appropriate, vaccines, physical rehabilitation as advised)

Choosing an alternative: The best option depends on PAH type, severity, existing treatments, blood pressure, other medical conditions, and how you respond over time.

Market and legal context in the United Kingdom (UK)

In the UK, PAH medicines such as Revatio are supplied according to national prescribing and supply regulations. Healthcare providers follow licensed indications and patient monitoring requirements. Medicines may be prescribed and dispensed through authorised routes and pharmacy services.

Quality and authenticity: When buying medicines online, choose reputable UK-compliant pharmacies. Look for clear product information, secure payment, and transparent delivery and returns policies. Avoid counterfeit medicines.

Recent guidance and clinical practice: PAH treatment is managed by specialist services, with treatment selection based on severity, functional class, imaging and blood tests, and ongoing monitoring. Clinical recommendations may evolve, and local specialist centres may update preferred strategies for combination therapy.

Note: If your treatment plan changes, your dose and medicine schedule should be updated accordingly by your healthcare team.

Delivery, availability and packaging

Online pharmacies in the UK may offer delivery services to eligible UK addresses. Availability can vary depending on stock levels and the strength/pack size required.

• Packaging: Tablets are typically supplied in sealed packs with manufacturer labels and leaflets.
• Delivery times: Depend on the chosen delivery option (standard or express) and postcode coverage.
• Cold chain: Usually not required for sildenafil tablets.
• Storage: Store at room temperature as directed on the pack, protect from moisture, and keep out of reach of children.

Important: Always check the pack strength, expiry date, and that the medicine matches what you ordered.

Frequently Asked Questions (FAQ)

1) What is Revatio used for?

Revatio (sildenafil citrate) is used to treat pulmonary arterial hypertension (PAH) by helping relax blood vessels in the lungs and reduce pulmonary artery pressure.

2) How soon will Revatio start working?

Some people may feel effects within hours after a dose, but PAH benefits are often assessed over time. Your clinician will monitor your response using symptoms and clinical measures.

3) Can I take Revatio if I miss a dose?

If you miss a dose, follow the instructions given with your medicine or contact your healthcare team/pharmacist for advice. In general, do not take double doses to make up for a missed tablet.

4) Can I take Revatio with food?

Revatio can usually be taken with or without food. If you experience stomach discomfort, taking it with a light meal may improve tolerability.

5) Is it safe to drink alcohol while taking Revatio?

Alcohol may increase the chance of dizziness or low blood pressure when combined with sildenafil. Keep alcohol intake moderate and avoid if you notice symptoms.

6) What medicines should I avoid?

Do not use Revatio with nitrates (for example glyceryl trinitrate) or “poppers”. Tell your pharmacist about all other medicines, including antibiotics, antifungals, HIV medicines, blood pressure treatments, and urinary medicines.

7) Can Revatio be taken with other PAH medicines?

Often, PAH medicines are combined, but this must be managed by specialists to balance benefits and blood pressure effects. Never change your regimen without medical advice.

8) Are there any warnings about vision or hearing?

Rarely, sildenafil-containing medicines have been associated with sudden vision or hearing problems. If you experience sudden changes, seek urgent medical help.

9) Will Revatio affect driving?

If you feel dizzy, lightheaded, or experience visual changes, avoid driving and seek advice.

10) How should Revatio be stored?

Store according to the pack instructions (typically at room temperature, away from moisture), and keep out of reach of children.

At-a-glance safety summary

Further help

If you have questions about Revatio, side effects, or interactions with your current medicines, speak to a pharmacist or your healthcare team. Keeping an up-to-date list of all medicines (including over-the-counter products and herbal supplements) can help ensure safe use.