Sildenafil and Lisinopril: Can They Be Taken Together?

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At a glance

What Is Sildenafil and How Does It Work?

Sildenafil is the active ingredient in Viagra and is licensed in the UK to treat erectile dysfunction (ED) [3]. It belongs to a group of medicines called PDE5 inhibitors, which work by relaxing blood vessels in the penis, allowing increased blood flow when you are sexually aroused. Sildenafil does not cause an erection on its own—sexual stimulation is still needed for it to work.

Sildenafil is available in 25mg, 50mg, and 100mg tablets. The usual starting dose is 50mg, taken about one hour before sexual activity, with a maximum of one dose in 24 hours [3]. The medicine typically works for four to six hours, though this varies between individuals. Common side effects include headache, flushing, indigestion, and nasal congestion, which are usually mild and short-lived.

At Cured Pharmacy, sildenafil is available only after an online consultation reviewed by a UK-registered prescriber, who will check your medical history, current medicines, and whether sildenafil is suitable and safe for you.

What Is Lisinopril and Why Is It Prescribed?

Lisinopril is a medicine used to treat high blood pressure (hypertension) and heart failure, and to protect the kidneys in people with diabetes. It belongs to a class of medicines called ACE inhibitors (angiotensin-converting enzyme inhibitors), which work by relaxing and widening your blood vessels, making it easier for your heart to pump blood around your body [2].

Lisinopril is usually taken once a day, and it may take several weeks to reach its full effect on blood pressure. Common side effects include a persistent dry cough, dizziness (especially when standing up), headache, and fatigue. Because lisinopril lowers blood pressure, it is important that your blood pressure is stable and well-controlled before adding any other medicine that can also affect blood pressure.

Many men with high blood pressure also experience erectile dysfunction, which can be related to the underlying condition itself or, less commonly, to the medication. If you have noticed changes in your erections since starting lisinopril, it is worth discussing this with your GP, as ED can sometimes be an early warning sign of cardiovascular disease [1].

Can You Take Sildenafil and Lisinopril Together?

Yes, sildenafil and lisinopril can usually be taken together, but only under the supervision of a prescriber who has reviewed your full medical history [2][3]. There is no absolute contraindication between these two medicines, meaning they are not in the dangerous category of combinations (such as sildenafil with nitrates, which must never be taken together). However, both medicines can lower blood pressure, so there is a potential for an additive effect that may cause dizziness, light-headedness, or fainting, particularly when standing up quickly.

Your prescriber will check that your blood pressure is stable and well-controlled on lisinopril before prescribing sildenafil. They will also review your cardiovascular health to ensure that sexual activity itself is safe for you, as it does place extra demands on the heart [2]. If you have recently had a heart attack or stroke, have unstable angina, or have very low blood pressure, sildenafil may not be suitable.

It is essential to declare all your current medicines—including lisinopril and any other blood pressure tablets—during your consultation. Never stop or change your prescribed blood pressure medicine without advice from your GP or prescriber, as this can be dangerous.

How the Interaction Works in Plain English

Lisinopril lowers blood pressure by relaxing your blood vessels. Sildenafil also causes blood vessels to relax, though its main action is in the penis. When taken together, the combined effect on your blood vessels can lead to a greater drop in blood pressure than either medicine alone. For most men whose blood pressure is stable and well-controlled, this is manageable and does not cause problems. However, if your blood pressure drops too much, you may feel dizzy, faint, or unsteady, especially when you stand up or move quickly. This is why your prescriber will start you on the lowest suitable dose of sildenafil and monitor how you respond.

What you need to know

• Sildenafil and lisinopril can usually be taken together if your blood pressure is stable and well-controlled.
• Both medicines can lower blood pressure, so watch for dizziness and start with the lowest suitable dose.
• Never take sildenafil with nitrates, nicorandil, or poppers—this combination is dangerous.
• Declare all your medicines during your consultation, and never stop lisinopril without medical advice.
• Seek urgent help for chest pain, prolonged erection over four hours, or sudden vision or hearing loss.

What Your Prescriber Checks Before Prescribing Sildenafil with Lisinopril

During your online consultation at Cured Pharmacy, the prescriber will ask detailed questions about your current medicines, including the dose of lisinopril you take and how long you have been on it. They will want to know whether your blood pressure is stable and well-controlled, and whether you have experienced any side effects such as dizziness or fainting [2].

The prescriber will also review your cardiovascular history, including any history of heart attack, stroke, angina, heart failure, or abnormal heart rhythms. They will check whether you are taking any other medicines that can interact with sildenafil, such as alpha-blockers (e.g. doxazosin, tamsulosin), nitrates (e.g. GTN spray, isosorbide mononitrate), or potent CYP3A4 inhibitors (e.g. ritonavir, ketoconazole) [3].

If you are taking other blood pressure medicines in addition to lisinopril—such as amlodipine, bisoprolol, or bendroflumethiazide—the prescriber will take this into account, as the combined blood-pressure-lowering effect may be greater. They may recommend starting with a lower dose of sildenafil (25mg) and monitoring how you feel. It is important to be honest and thorough in your answers, as this ensures the safest and most effective treatment for you.

Practical Advice for Taking Sildenafil and Lisinopril Safely

If your prescriber approves sildenafil, take it exactly as directed. The usual starting dose is 50mg, taken about one hour before sexual activity, but your prescriber may recommend 25mg if you are on multiple blood pressure medicines or have other risk factors [3]. Do not take more than one dose in 24 hours, and do not increase the dose without consulting your prescriber first.

Be aware of how you feel after taking sildenafil, especially the first time. If you experience dizziness, light-headedness, or feel faint, sit or lie down until the feeling passes. Avoid standing up quickly, particularly after lying down or sitting for a while. Drinking alcohol can make dizziness worse and may also make it harder to get an erection, so it is best to limit alcohol when planning to use sildenafil [3].

Continue taking your lisinopril as prescribed by your GP—do not stop or skip doses because you are taking sildenafil. If you experience any unusual symptoms, such as chest pain during sex, a prolonged erection lasting more than four hours, or sudden changes in vision or hearing, stop sexual activity and seek urgent medical help. Keep your GP informed that you are using sildenafil, especially if your blood pressure control changes or if new medicines are added to your treatment.

Lifestyle Tips to Support Both Medicines

Maintaining a healthy lifestyle can improve both your blood pressure control and your erectile function. Regular physical activity, a balanced diet low in salt and saturated fat, maintaining a healthy weight, and not smoking all support cardiovascular health and can enhance the effectiveness of both lisinopril and sildenafil [1]. Managing stress and getting enough sleep are also important. If you have diabetes or high cholesterol, keeping these well-controlled will further reduce your risk of complications and improve your overall wellbeing.

When to get urgent help

• Chest pain or severe dizziness during or after sex—call 999 immediately
• Erection lasting longer than 4 hours (priapism)—go to A&E straight away
• Sudden loss of vision in one or both eyes—seek urgent medical attention
• Sudden decrease or loss of hearing, sometimes with ringing in the ears—contact a doctor urgently
• Severe fainting or collapse—call 999

Call 999 or go to A&E in an emergency, or contact NHS 111 for urgent advice.

When Sildenafil and Lisinopril Should Not Be Combined

While sildenafil and lisinopril can usually be taken together, there are some situations where sildenafil is not suitable, regardless of whether you take lisinopril. Do not take sildenafil if you are using nitrate medicines for angina (such as GTN spray, isosorbide mononitrate, or isosorbide dinitrate), nicorandil, riociguat, or recreational drugs known as 'poppers' (amyl or alkyl nitrites). The combination of sildenafil with any of these can cause a dangerous, potentially life-threatening drop in blood pressure [3].

Sildenafil is also not suitable if you have very low blood pressure (hypotension), have had a recent heart attack or stroke (usually within the last six months), have unstable angina or severe heart failure, or if your doctor has advised you to avoid sexual activity due to cardiovascular risk [2][3]. If you have a history of sudden vision loss due to a condition called non-arteritic anterior ischaemic optic neuropathy (NAION), sildenafil should not be used.

If you are taking alpha-blockers for prostate symptoms (such as tamsulosin or doxazosin) in addition to lisinopril, extra caution is needed, as the combination with sildenafil can increase the risk of low blood pressure and dizziness. Your prescriber will ensure you are stable on the alpha-blocker and will start you on the lowest dose of sildenafil. Always declare every medicine you take, including over-the-counter medicines, herbal remedies (such as St John's wort), and supplements, as these can also interact.

Warning Signs to Watch For

Seek urgent medical help if you experience chest pain, severe dizziness, fainting, or palpitations after taking sildenafil. If you develop an erection that lasts longer than four hours (priapism), go to A&E immediately, as this requires urgent treatment to prevent permanent damage. Sudden loss of vision in one or both eyes, or sudden decrease or loss of hearing (sometimes with ringing in the ears), are rare but serious side effects that require immediate medical attention [3]. If you are unsure whether a symptom is serious, contact NHS 111 for advice or call 999 in an emergency.