Stendra (Avanafil) – Patient Guide (UK)

Stendra is a medicine containing avanafil, used to treat erectile dysfunction (ED) in adult men. This page explains how it works, how to take it safely, what to expect, and what to discuss with a healthcare professional—tailored to the context of the United Kingdom.

Important: This information is for education. Everyone’s health situation is different. Always follow the directions provided by your prescriber or pharmacist.

Quick facts

• Active ingredient: Avanafil
• Common use: Erectile dysfunction (ED)
• How it works: Helps increase blood flow to the penis during sexual stimulation
• Typical onset: Often within 15–30 minutes (may vary)
• Duration: Effects can last for several hours
• Available strengths: Commonly 50 mg, 100 mg, and 200 mg tablets

What is Stendra?

Stendra is an oral medicine from the phosphodiesterase type 5 (PDE5) inhibitor group. Like other medicines in this group, it does not automatically produce an erection. Instead, it supports normal erectile response by improving blood flow when you are sexually stimulated.

In the UK, ED is common and treatable. If ED is persistent, consider discussing the underlying causes as well—such as diabetes, high blood pressure, smoking, stress, anxiety, or certain medications.

How Stendra works (mechanism of action)

To understand how Stendra works, it helps to know the role of the blood vessels and smooth muscle in erectile function.

• Sexual arousal triggers release of nitric oxide in the body.
• Nitric oxide activates a natural chemical pathway that increases cGMP (cyclic guanosine monophosphate).
• cGMP relaxes the smooth muscle in the penis, allowing more blood to flow in and remain there during erection.
• Avanafil blocks PDE5, an enzyme that normally breaks down cGMP.
• By blocking PDE5, avanafil helps maintain higher cGMP levels, supporting improved erection quality and firmness during sexual stimulation.

Key point: Stendra enhances the body’s natural erectile response; it still requires sexual stimulation to work effectively.

Pharmacokinetics (how the body handles avanafil)

Pharmacokinetics describes how a drug is absorbed, distributed, metabolised, and eliminated.

• Absorption: Avanafil is absorbed after oral dosing. Peak blood levels are reached in roughly 30–60 minutes for many people, but timing can vary (especially with food).
• Effect of food: Heavy meals—particularly those high in fat—can reduce or delay absorption.
• Metabolism: Primarily metabolised in the liver (notably via CYP3A4 enzyme pathways).
• Elimination: Metabolites are removed mainly through the liver/bile and kidneys.
• Half-life: The active substance remains in the body long enough to allow dosing a limited number of times per day, based on safety guidance.

If you have liver impairment or take interacting medicines, your dose and frequency may need adjustment.

Typical use and indications

Indication

Stendra is indicated for the treatment of erectile dysfunction in adult men, defined as the inability to achieve or maintain an erection sufficient for satisfactory sexual performance.

Who may be suitable?

Many men with ED can take a PDE5 inhibitor. However, suitability depends on your cardiovascular health and medicines—especially whether you use nitrates or drugs affecting cGMP pathways.

• You should be assessed if you have heart disease, low blood pressure, a history of stroke, or significant cardiovascular risk.
• You should not use Stendra if you take nitrates for chest pain (see safety section below).

How to take Stendra: dosing and timing

Dosage should be individualised based on how you respond and your risk factors. Below is general guidance consistent with how avanafil is commonly prescribed and labelled.

Recommended starting dose (typical)

• 50 mg or 100 mg may be used initially, depending on clinical judgement.
• Your prescriber may adjust the dose to 100 mg or 200 mg if needed and if tolerated.

Maximum frequency

Do not take Stendra more often than recommended in your specific instructions. In general, PDE5 inhibitors are used sparingly and dosing frequency is limited to reduce the risk of side effects.

When to take it

• Stendra is usually taken before sexual activity.
• For many people, it may work within 15–30 minutes.
• Some individuals may need more time; if not effective, clinicians may adjust dose or timing.

Practical timing example

Example: If you plan sex at 8:00 pm and your healthcare professional advised taking it about 30–60 minutes beforehand, you might take it around 7:00–7:30 pm. If you ate a heavy, fatty meal, you may need to allow more time (or keep meals lighter—see food interactions).

Food interactions (what to know about eating)

Food can influence absorption of avanafil and therefore the speed and strength of its effect.

• Heavy or high-fat meals: may delay onset and reduce the peak effect.
• Lighter meals: typically cause less delay.
• Practical tip: If you want more predictable timing, consider taking Stendra with a lighter meal or when you are not very full.

If you notice that it takes longer to work after meals, discuss this with a pharmacist or prescriber to adjust your timing strategy.

Alcohol and Stendra

Small amounts of alcohol may not completely prevent Stendra from working, but alcohol can affect sexual performance and cardiovascular stability.

• Alcohol may worsen ED: by reducing sexual arousal and increasing the likelihood of erection difficulty.
• Higher alcohol intake can lower blood pressure: PDE5 inhibitors also can lower blood pressure, so combining them with heavy drinking may increase dizziness or light-headedness.
• Safety practical advice: Avoid heavy drinking. If you feel dizzy, do not drive and seek medical help if symptoms are severe or persistent.

Seek urgent help: if you develop chest pain, fainting, severe dizziness, or unusual shortness of breath.

Medicine interactions (important safety information)

Avanafil can interact with medicines that affect liver enzymes (especially CYP3A4) or blood pressure.

Absolute contraindication with nitrates

Do not take Stendra if you use nitrates (often used for angina/chest pain) such as:

• Glyceryl trinitrate (GTN)
• Isosorbide mononitrate / dinitrate
• Other nitrate preparations

Why: Combining PDE5 inhibitors with nitrates can cause a dangerous fall in blood pressure.

Nitrite “poppers” and other related substances

Recreational nitrite inhalants (“poppers”) may also interact with PDE5 inhibitors and should be avoided.

Medicines to use with caution

Some medicines may increase avanafil levels, increasing side effects such as headache, flushing, dizziness, or low blood pressure. Others may reduce effectiveness.

• Strong CYP3A4 inhibitors (e.g., some antifungals and certain antibiotics/antivirals) may increase avanafil exposure. Your prescriber may lower dose or avoid use.
• Alpha-blockers used for prostate symptoms or blood pressure (e.g., doxazosin, tamsulosin): can increase risk of dizziness or low blood pressure if not coordinated properly.
• Other PDE5 inhibitors (e.g., sildenafil, tadalafil, vardenafil): do not use concurrently.
• Antihypertensives: may add to blood pressure-lowering effects.
• Riociguat (for pulmonary hypertension): is generally incompatible with PDE5 inhibitors.

What to do

• Tell your pharmacist or prescriber about all medicines you take, including over-the-counter products and herbal supplements.
• If you start a new medicine, check whether it interacts.

Safety profile and possible side effects

Most people tolerate Stendra well when used correctly. Side effects are usually mild to moderate and may lessen as your body adjusts.

Common side effects

• Headache
• Flushing (warmth or redness)
• Dizziness
• Blocked or runny nose
• Indigestion or nausea
• Back pain (less common than with some other PDE5 inhibitors)

Serious but uncommon reactions

Get urgent medical help if you have:

• Chest pain or fainting
• Severe dizziness or signs of dangerously low blood pressure
• Prolonged erection (priapism) lasting more than a few hours—this requires emergency care
• Sudden vision or hearing changes
• Severe allergic reactions (e.g., swelling of face/lips, difficulty breathing, rash)

Who should be extra cautious?

• Men with significant heart or circulation problems
• Men with history of stroke or low blood pressure
• Those with liver impairment or severe kidney disease may need dose adjustments
• Anyone taking medicines that strongly affect CYP3A4 pathways

How to use Stendra effectively: practical tips

• Use sexual stimulation: Avanafil supports arousal but doesn’t replace it. Allow time for relaxation and stimulation.
• Plan your timing: Try timing it consistently. If it’s not working, avoid increasing frequency—discuss dose and timing with a clinician.
• Keep meals lighter beforehand: particularly if you’re aiming for a quicker onset.
• Manage stress and anxiety: ED can become self-reinforcing; addressing anxiety often improves outcomes.
• Avoid smoking and excessive alcohol: both can reduce erectile function.
• Track what works: note the dose, time taken, meal size, and response to help fine-tune use with your healthcare team.

Typical expectations: when you should see results

Some men notice improvements the first time they try a PDE5 inhibitor, while others may need dose adjustment or timing changes. If Stendra doesn’t help after several attempts, it doesn’t necessarily mean it’s the wrong medicine—there may be a need to consider underlying causes or alternative options.

If you have not had satisfactory results, it is best to review:

• That the timing is correct for you
• Whether food or alcohol affected onset
• Medication interactions
• Whether another diagnosis contributes to ED

Alternative options for ED in the UK

Stendra is one option. Depending on your situation, other treatments may be considered.

Other PDE5 inhibitors

• Sildenafil (often shorter onset window; commonly used)
• Tadalafil (often longer duration; sometimes chosen for flexibility)
• Vardenafil

Your prescriber may recommend switching based on speed of effect, duration, side effects, and interactions.

Non-PDE5 options

• Lifestyle measures: weight management, exercise, smoking cessation, limiting alcohol
• Psychosexual support: counselling can help especially when anxiety contributes
• Vacuum erection devices
• Injections or urethral therapies (specialist-led)
• For some men: evaluation for hormonal or vascular causes

In the UK, ED is often approached stepwise: start with safe oral options where appropriate and broaden evaluation if ED is persistent or accompanied by other symptoms.

Market and legal context (United Kingdom)

In the UK, medicines are regulated by the Medicines and Healthcare products Regulatory Agency (MHRA), with additional oversight through the wider UK healthcare framework. ED treatments are medicines and are supplied through regulated channels.

Reputable UK online pharmacies typically require completion of a health questionnaire to check suitability and interactions, and may involve a review by a qualified healthcare professional where appropriate. This helps ensure medicines are used safely.

If you are buying any ED medication online, choose a supplier that is transparent about:

• UK regulatory compliance
• Clear product identity and dosage forms
• Safety screening for interacting conditions and medicines
• Customer support and delivery terms

Recent guidance and responsible use (general)

Ongoing clinical guidance across Europe and the UK consistently emphasises:

• Screening for cardiovascular risk and contraindications (particularly nitrate use)
• Appropriate dosing and avoidance of combining PDE5 inhibitors
• Awareness of drug interactions (CYP3A4 inhibitors, alpha-blockers, riociguat)
• Prompt medical attention for rare serious adverse events such as priapism

If you have recurrent ED or ED that appears suddenly, it’s sensible to seek medical review to rule out contributing factors (e.g., diabetes, vascular disease, medication side effects, hormonal changes).

Delivery and availability

Availability of Stendra may vary by strength and supply chain timing. In general, online pharmacies in the UK may offer different delivery options, such as:

• Standard delivery (often 2–3 working days, depending on courier and region)
• Express delivery (where available)
• Trackable shipments with delivery updates

Check the pharmacy listing for:

• In-stock status
• Estimated delivery times
• Packaging and temperature/handling conditions (if applicable)
• Returns policy and how to contact customer support

Storage and handling

• Keep tablets in the original packaging.
• Store below 25°C (unless the label says otherwise) and protect from excess moisture.
• Keep out of the sight and reach of children.

FAQ: Stendra (Avanafil) in the UK

1) How fast does Stendra work?

Many people find effects within 15–30 minutes. However, onset can vary—especially with heavy or fatty meals. If you’re planning sex, taking it with sensible meal timing can help.

2) How long does it last?

Effects can last for several hours, allowing flexibility during the sexual window. Individual duration varies.

3) Can I take Stendra every day?

Stendra is generally taken as needed before sexual activity, with dosing frequency limited by safety considerations. Follow the specific advice given to you.

4) What happens if Stendra doesn’t work for me?

Possible reasons include timing, food/alcohol effects, dose, inadequate sexual stimulation, or interactions with other medicines. If repeated attempts are unsuccessful, discuss adjusting dose/timing or considering alternative options.

5) Can I take Stendra with meals?

Yes, but if the meal is heavy or high in fat, it may delay onset or reduce peak effect. Many people prefer a lighter meal for more predictable timing.

6) Is Stendra safe with alcohol?

Moderate alcohol may be tolerated by some people, but heavy drinking can worsen ED and increase risks such as dizziness due to additive blood pressure effects. Avoid excessive alcohol.

7) What medicines should I avoid?

Do not take Stendra if you use nitrates for chest pain. Also be cautious with medicines that affect blood pressure or interact with avanafil metabolism (e.g., certain CYP3A4 inhibitors, alpha-blockers). Your pharmacist can advise on your specific list of medicines.

8) Can I take Stendra with other ED tablets?

Do not combine PDE5 inhibitors (for example, do not take Stendra and sildenafil/tadalafil together). Combination therapy increases side effects risk.

9) Are there any red-flag side effects?

Yes. Seek urgent medical help if you experience chest pain, fainting, severe dizziness, sudden vision/hearing changes, severe allergic reaction, or an erection lasting long enough to suggest priapism.

10) Does Stendra work for all causes of ED?

It works best for ED where sexual stimulation and blood flow mechanisms are involved. If ED is due to other causes (for example, neurological conditions, hormonal issues, or significant vascular disease), you may need additional assessment and a broader plan.

Summary

Stendra (avanafil) is an oral PDE5 inhibitor used to treat erectile dysfunction in adult men. It supports erectile function by improving blood flow during sexual stimulation. Timing matters: it often works within 15–30 minutes, but heavy meals can slow onset. Avoid nitrates and be cautious with interacting medicines, alcohol, and cardiovascular risk. If you have persistent ED or concerns about safety, consult a healthcare professional for personalised advice.