Tadalafil and Mefloquine: 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 licensed in the UK for treating erectile dysfunction in adult men [4]. It belongs to a group of medicines called PDE5 inhibitors, which work by relaxing the blood vessels in the penis, allowing increased blood flow when you are sexually aroused. Unlike some ED treatments, tadalafil does not cause an erection on its own—sexual stimulation is still needed.

Tadalafil is available in two forms: on-demand tablets (usually 10 mg or 20 mg) taken at least 30 minutes before sexual activity, with effects lasting up to 36 hours, and daily low-dose tablets (2.5 mg or 5 mg) taken once a day at the same time [4]. The branded version is known as Cialis, but generic tadalafil is widely available and works in exactly the same way. At Cured Pharmacy, tadalafil is available on prescription following an online consultation reviewed by a UK-registered prescriber.

What Is Mefloquine and Why Is It Prescribed?

Mefloquine is an antimalarial medicine used to prevent and treat malaria, a serious infection spread by mosquitoes in many tropical and subtropical regions. It is typically prescribed for travellers visiting areas where malaria is common, or for people living in those regions. Mefloquine works by killing the malaria parasites in the blood.

This medicine is usually taken once a week for malaria prevention, starting before travel and continuing for several weeks after returning. Mefloquine can cause side effects in some people, including dizziness, sleep disturbances, mood changes, and occasionally more serious neurological or psychiatric effects. Because of these potential side effects, your doctor will assess whether mefloquine is the right antimalarial for you, especially if you have a history of mental health conditions, epilepsy, or heart rhythm problems.

When to get urgent help

• Erection lasting more than 4 hours (priapism)—go to A&E immediately
• Sudden loss of vision or hearing—stop tadalafil and seek urgent medical help
• Chest pain during sexual activity—stop and call 999
• Severe dizziness, fainting, or irregular heartbeat—contact your doctor or call 999
• Severe psychiatric symptoms (hallucinations, severe anxiety, seizures) while on mefloquine—call 999

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

Tadalafil and Mefloquine: Is There a Direct Interaction?

No major direct interaction between tadalafil and mefloquine is commonly reported in clinical practice or standard drug interaction databases. This means that, in most cases, taking tadalafil for erectile dysfunction while you are on mefloquine for malaria prevention or treatment should not cause a significant problem. Neither medicine is known to substantially affect the way the other works in the body.

However, it is important to remember that both medicines can have side effects that may overlap or add together. For example, mefloquine can sometimes cause dizziness or changes in heart rhythm, and tadalafil can lower blood pressure slightly, which may also cause dizziness or light-headedness in some men [4]. If you experience unusual symptoms when taking both medicines together, it is important to speak to your doctor or pharmacist.

What Your Prescriber Will Check

During your consultation at Cured Pharmacy, the prescriber will ask about all your current medicines, including mefloquine, as well as your full medical history. They will check for any conditions or other medicines that could make tadalafil unsuitable—such as recent heart problems, very low blood pressure, or medicines that interact dangerously with tadalafil (like nitrates or riociguat). Even though tadalafil and mefloquine do not have a major direct interaction, your prescriber needs the complete picture to ensure your treatment is safe and appropriate for you.

Other Medicines That Can Interact with Tadalafil

While tadalafil and mefloquine can generally be used together, there are some medicines that must never be taken with tadalafil because they can cause a dangerous drop in blood pressure. These include nitrates (such as GTN spray, isosorbide mononitrate, or isosorbide dinitrate), nicorandil, riociguat, and recreational drugs known as 'poppers' (amyl or alkyl nitrites). Do not take tadalafil with any of these medicines or substances [4].

Alpha-blockers (such as doxazosin, tamsulosin, or alfuzosin), used for prostate problems or high blood pressure, can also interact with tadalafil, increasing the risk of dizziness or fainting. If you take an alpha-blocker, your prescriber will usually start you on the lowest dose of tadalafil and ensure you are stable on your alpha-blocker first [4]. Potent CYP3A4 inhibitors—medicines like ritonavir, ketoconazole, itraconazole, or clarithromycin—can raise tadalafil levels in the blood, so your prescriber may need to adjust your tadalafil dose or choose a different ED treatment.

Always tell your prescriber about every medicine you take, including over-the-counter products, herbal remedies (such as St John's wort), and supplements. This helps them choose the safest and most effective treatment for you.

At a glance

Practical Advice for Taking Tadalafil and Mefloquine Together

If your prescriber has confirmed that tadalafil is suitable for you while you are taking mefloquine, follow the dosing instructions for both medicines carefully. Take tadalafil as prescribed—either on-demand at least 30 minutes before sexual activity, or once daily at the same time each day if you are on the low-dose daily regimen [4]. Continue taking mefloquine exactly as your doctor has advised for malaria prevention or treatment, usually once a week at the same time.

Be aware of how you feel when taking both medicines together, especially in the first few days. If you notice unusual dizziness, light-headedness, changes in vision or hearing, or any other concerning symptoms, stop taking tadalafil and contact your doctor or pharmacist for advice. Avoid drinking large amounts of alcohol, as this can worsen erectile dysfunction and increase the risk of side effects such as dizziness or low blood pressure.

If you are travelling to a malaria-endemic area and plan to take tadalafil with you, make sure you have enough supply and keep it in its original packaging with the patient information leaflet. Store both medicines as directed—usually at room temperature, away from moisture and direct sunlight.

When to Seek Medical Advice

Seek urgent medical help if you experience an erection lasting more than four hours (priapism), sudden loss of vision or hearing, or chest pain during sexual activity while taking tadalafil [4]. These are rare but serious side effects that need immediate attention. If you develop severe side effects from mefloquine—such as severe anxiety, hallucinations, seizures, or irregular heartbeat—contact your doctor or call 999 straight away. Do not stop taking mefloquine suddenly without medical advice, especially if you are in a malaria-risk area.

How to Get Tadalafil Safely from Cured Pharmacy

At Cured Pharmacy, a GPhC-registered online pharmacy (GPhC 9012511), you can request tadalafil and other ED treatments through a confidential online consultation. A UK-registered prescriber will review your medical history, current medicines (including mefloquine), and any health conditions to ensure tadalafil is safe and suitable for you. If approved, your medicine is dispensed by our pharmacy team and delivered discreetly to your door.

We offer a range of ED treatments, including generic tadalafil from £7.95 (or £6.36 for your first order with code Ednew), as well as other PDE5 inhibitors such as sildenafil, vardenafil, and avanafil [2][4]. All our medicines are sourced from licensed UK suppliers and meet the same quality standards as those dispensed in high-street pharmacies. If you have any questions about tadalafil and mefloquine, or any other aspect of your treatment, our pharmacist-led team is here to help.

Remember, if you are experiencing erectile dysfunction for the first time, it is a good idea to see your GP as well. ED can sometimes be an early warning sign of underlying health conditions such as heart disease or diabetes, and your doctor can arrange tests and provide advice on lifestyle changes that may help [1][2].

Why Choose Cured Pharmacy?

Cured Pharmacy combines the convenience of online ordering with the safety and professionalism of a fully regulated UK pharmacy. Every prescription is reviewed by a qualified prescriber, and our team is available to answer your questions and provide ongoing support. We understand that discussing erectile dysfunction can feel uncomfortable, so we have made the process as straightforward and discreet as possible, with plain packaging and fast, reliable delivery across the UK.

In summary

• Tadalafil and mefloquine can generally be taken together with no major direct interaction reported
• Your prescriber will review all your medicines during consultation to ensure tadalafil is safe for you
• Both medicines can cause dizziness; watch for unusual symptoms and seek advice if concerned
• Never take tadalafil with nitrates, nicorandil, riociguat, or poppers—this can be dangerous
• Cured Pharmacy offers tadalafil from £7.95 after a UK prescriber-reviewed online consultation

Frequently Asked Questions

Choose your treatment

Select from our recommended UK-licensed medications.

Answer quick questions

Select safe UK treatments. Quick answers.

Get it delivered fast

We will deliver direct to you as quickly as tomorrow.