Tadalafil and Rivastigmine: Can They Be Taken Together?

Takes less than 2 minutes to complete 100% online

What is tadalafil and how does it work?

Tadalafil is a prescription medicine used to treat erectile dysfunction (ED) in men [4]. It belongs to a group of medicines called phosphodiesterase type 5 (PDE5) inhibitors, which work by relaxing blood vessels in the penis, allowing increased blood flow when you are sexually aroused [1][4].

Tadalafil is available in two forms: on-demand tablets (10mg or 20mg) taken at least 30 minutes before sexual activity, with effects lasting up to 36 hours, and daily low-dose tablets (2.5mg or 5mg) taken once a day [4]. The medicine only works when you are sexually stimulated—it does not cause an automatic erection [1].

Common brand names include Cialis, but generic tadalafil is widely available and just as effective. At Cured Pharmacy, all tadalafil treatments require an online consultation reviewed by a UK-registered prescriber to ensure they are safe and suitable for you.

What is rivastigmine and why is it prescribed?

Rivastigmine is a prescription medicine used to treat mild to moderate dementia in people with Alzheimer's disease or Parkinson's disease. It belongs to a class of medicines called cholinesterase inhibitors, which work by increasing levels of a chemical messenger called acetylcholine in the brain, helping to improve memory, thinking and daily function.

Rivastigmine is available as capsules, oral solution, or skin patches. The dose is usually started low and gradually increased to reduce side effects such as nausea, vomiting, dizziness or loss of appetite. It does not cure dementia but may help slow the worsening of symptoms for a period of time.

Because rivastigmine affects the nervous system and can influence heart rate and blood pressure in some people, your prescriber will consider all your current medicines—including any treatments for erectile dysfunction—when reviewing your overall care plan.

When to get urgent help

• Erection lasting more than 4 hours (priapism)—go to A&E immediately
• Sudden loss of vision or hearing—seek urgent medical help
• Chest pain during sexual activity—stop and call 999
• Severe dizziness, fainting or very slow heart rate—seek same-day medical advice
• New or severe side effects from either medicine—contact your GP or pharmacist promptly

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

Can you take tadalafil and rivastigmine together?

There is no major interaction commonly reported between tadalafil and rivastigmine, and many men take both medicines together without problems [2][3][4]. Rivastigmine does not significantly affect the way tadalafil works, and tadalafil does not interfere with rivastigmine's action on brain chemistry.

However, both medicines can affect blood pressure and heart function in different ways. Tadalafil can cause a mild drop in blood pressure, particularly when you first stand up, and rivastigmine can occasionally slow the heart rate or cause dizziness. Your prescriber will review your full medical history, current medicines and overall health during consultation to ensure the combination is safe for you.

It is essential to declare all your medicines—including rivastigmine, any other dementia treatments, blood pressure tablets, and over-the-counter products—during your online consultation. Never stop or change a prescribed medicine without speaking to your doctor or pharmacist first.

What your prescriber checks

During your consultation, the prescriber will ask about your heart health, blood pressure, other medicines (especially nitrates, alpha-blockers, or potent CYP3A4 inhibitors), and any history of stroke, heart attack or severe liver or kidney problems [2][3][4]. They will also check whether sexual activity is safe for you, as this is an important consideration for anyone with cardiovascular or neurological conditions. If you are taking rivastigmine, the prescriber will consider your overall health picture, including the reason for the dementia treatment and any other conditions you may have.

How tadalafil and rivastigmine interact in your body

Tadalafil works by blocking an enzyme called phosphodiesterase type 5 (PDE5) in the smooth muscle of blood vessels in the penis, leading to relaxation and increased blood flow during sexual arousal [4]. It is broken down in the liver mainly by an enzyme called CYP3A4.

Rivastigmine works in the brain by blocking the enzyme acetylcholinesterase, which normally breaks down the neurotransmitter acetylcholine. By preventing this breakdown, rivastigmine increases acetylcholine levels, which may help improve memory and thinking. Rivastigmine is broken down differently from tadalafil and does not significantly affect the CYP3A4 enzyme.

Because the two medicines work on different systems and are metabolised by different pathways, they do not directly interfere with each other's breakdown or action. However, both can have effects on the cardiovascular system—tadalafil by lowering blood pressure slightly, and rivastigmine occasionally by slowing heart rate—so your prescriber will assess whether the combination is appropriate for your individual health profile.

At a glance

Practical advice for taking tadalafil and rivastigmine safely

If your prescriber approves tadalafil while you are taking rivastigmine, follow the dosing instructions carefully. Take tadalafil on-demand tablets at least 30 minutes before sexual activity (effects can last up to 36 hours), or take daily tadalafil at the same time each day [4]. Continue taking rivastigmine exactly as your doctor has prescribed—do not adjust the dose or timing without medical advice.

Be aware of side effects from both medicines. Common side effects of tadalafil include headache, indigestion, back pain, muscle aches, flushing and a blocked or runny nose [4]. Rivastigmine can cause nausea, vomiting, diarrhoea, dizziness, loss of appetite and tiredness. If you experience dizziness or light-headedness, stand up slowly from sitting or lying down, and avoid heavy alcohol, which can worsen these effects and make erectile dysfunction worse [1][2].

Keep all your healthcare professionals informed. Let your GP, specialist and pharmacist know about every medicine you take, including over-the-counter products and herbal supplements. If you start any new medicine, check with your pharmacist or doctor whether it is safe to continue tadalafil.

When to seek help

Seek urgent medical help if you experience an erection lasting more than four hours (priapism), sudden loss of vision or hearing, severe dizziness or fainting, or chest pain during sexual activity [3][4]. If you notice new or worsening side effects from either medicine, or if rivastigmine side effects become troublesome, speak to your GP or pharmacist promptly. Never stop rivastigmine suddenly without medical advice, as this can affect your dementia symptoms.

Other medicines and considerations with tadalafil and rivastigmine

While tadalafil and rivastigmine can usually be taken together, other medicines you take may pose more significant interactions. Never take tadalafil with nitrates (such as GTN spray, isosorbide mononitrate or dinitrate), nicorandil, riociguat, or recreational drugs called 'poppers' (amyl or alkyl nitrites)—this combination can cause a dangerous drop in blood pressure [3][4]. Do not take tadalafil with another PDE5 inhibitor such as sildenafil or vardenafil.

If you take alpha-blockers for prostate symptoms or blood pressure (such as doxazosin, tamsulosin, alfuzosin or terazosin), you should be stable on the alpha-blocker before starting tadalafil, and your prescriber will usually recommend the lowest dose of tadalafil to reduce the risk of low blood pressure and dizziness [3][4]. Potent CYP3A4 inhibitors—including some HIV medicines (ritonavir, cobicistat), antifungals (ketoconazole, itraconazole), and antibiotics (clarithromycin)—can raise tadalafil levels, requiring dose adjustment [4].

Other blood pressure medicines, CYP3A4 inducers (such as rifampicin, carbamazepine, phenytoin or St John's wort), and grapefruit juice can also affect tadalafil. Your prescriber and pharmacist will check every current medicine during your consultation to identify any interactions and adjust treatment accordingly [2][3][4].

Lifestyle and overall health

Erectile dysfunction can be an early warning sign of heart disease or diabetes, so it is important to see your GP for a full health check if you have new or worsening ED [1][2]. Lifestyle changes—such as stopping smoking, reducing alcohol, losing weight if needed, exercising regularly and managing stress—can improve both erectile function and overall health. If you are taking rivastigmine for dementia, maintaining good cardiovascular health is particularly important, as heart and brain health are closely linked.

In summary

• No major interaction is commonly reported between tadalafil and rivastigmine
• Your prescriber reviews all medicines and health conditions during consultation
• Both medicines can affect blood pressure or heart rate in different ways
• Declare all current medicines including rivastigmine during your online consultation
• Never take tadalafil with nitrates, nicorandil or another PDE5 inhibitor

Faq