Tadalafil and Temazepam: Can You Take Them Together?

Tadalafil and Temazepam: Understanding the Interaction

Published: 26 October 2026

Many men taking tadalafil and temazepam together wonder whether the combination is safe. Tadalafil is a prescription medicine used to treat erectile dysfunction (ED), while temazepam is a benzodiazepine prescribed for short-term insomnia. Although there is no major direct interaction between these two medicines, both can lower blood pressure and cause dizziness, so your prescriber will carefully assess your suitability before approving treatment.

What is tadalafil and how does it work?

Tadalafil is a phosphodiesterase type 5 (PDE5) inhibitor licensed in the UK to treat erectile dysfunction [4]. It works by relaxing blood vessels in the penis, allowing increased blood flow when you are sexually aroused. Tadalafil is the active ingredient in branded Cialis and is available in generic forms at lower cost.

Tadalafil comes in two dosing options: on-demand tablets (10mg or 20mg) taken at least 30 minutes before sexual activity, with effects lasting up to 36 hours, and daily tablets (2.5mg or 5mg) taken once a day regardless of when you plan to have sex [4]. All PDE5 inhibitors require sexual stimulation to work—they do not cause an automatic erection.

Common side effects include headache, indigestion, back pain, muscle aches, flushing, and nasal congestion [4]. Tadalafil is not suitable for men taking nitrates, nicorandil, riociguat, or recreational drugs called 'poppers', as the combination can cause a dangerous drop in blood pressure. Your prescriber will check your medical history and current medicines before approving tadalafil.

What is temazepam and why is it prescribed?

Temazepam is a benzodiazepine medicine prescribed for the short-term treatment of severe insomnia that is disabling or causing extreme distress. It works by enhancing the effect of a neurotransmitter called GABA in the brain, which has a calming effect and helps you fall asleep more easily.

Temazepam is usually prescribed at the lowest effective dose (10mg or 20mg) and for the shortest possible time—typically no more than two to four weeks—because long-term use can lead to tolerance, dependence, and withdrawal symptoms. Common side effects include drowsiness the next day, confusion, dizziness, muscle weakness, and impaired coordination.

Because temazepam can cause drowsiness and affect your balance, it is important not to drive, operate machinery, or make important decisions while taking it. Alcohol should be avoided, as it increases sedation and the risk of accidents. Your GP will review your need for temazepam regularly and may suggest non-drug approaches to improve sleep, such as cognitive behavioural therapy for insomnia (CBT-I).

Can temazepam affect erectile function?

Benzodiazepines like temazepam do not directly cause erectile dysfunction, but they can reduce libido (sex drive) and may contribute to sexual difficulties in some men. Anxiety and poor sleep are both common causes of ED, so treating insomnia may indirectly improve erectile function for some men [1]. However, if you notice new or worsening ED after starting temazepam, discuss this with your GP—there may be alternative treatments or underlying causes that need addressing.

Is there an interaction between tadalafil and temazepam?

There is no major direct pharmacological interaction between tadalafil and temazepam—they work on different systems in the body and do not significantly affect each other's metabolism. However, both medicines can cause dizziness and lower blood pressure, so taking them together may increase the risk of feeling light-headed, unsteady, or faint, especially when standing up quickly.

Tadalafil lowers blood pressure slightly by relaxing blood vessels, and temazepam can cause drowsiness, confusion, and reduced coordination. If you take both medicines on the same day, you may be more likely to experience these side effects, particularly if you also drink alcohol or take other medicines that affect blood pressure or cause sedation.

Your prescriber will ask about all your current medicines, including temazepam, during the online consultation for tadalafil. They will assess whether the combination is suitable for you based on your overall health, other medicines, and any history of low blood pressure or falls. If approved, you will usually be advised to start on the lowest effective dose of tadalafil and to be cautious when standing up or moving around after taking either medicine.

What your prescriber will check

Before approving tadalafil, your prescriber will review your full medical history, including any heart conditions, blood pressure problems, recent stroke or heart attack, liver or kidney disease, and any medicines you take regularly or occasionally. They will specifically ask about temazepam and other sedatives, as well as any medicines that lower blood pressure, such as alpha-blockers or antihypertensives. If you are stable on temazepam and have no other contraindications, tadalafil is usually safe to prescribe, but your prescriber may recommend starting with a lower dose (such as 10mg on-demand) and monitoring how you respond.

Practical advice for taking tadalafil and temazepam together

If your prescriber approves both medicines, there are some practical steps you can take to minimise the risk of side effects. First, avoid drinking alcohol on days when you take either medicine, as alcohol increases drowsiness, dizziness, and the risk of low blood pressure. Second, be cautious when standing up from sitting or lying down—get up slowly to avoid feeling faint.

Temazepam is usually taken at bedtime, and tadalafil on-demand is taken 30 minutes to an hour before sexual activity. If you plan to take both on the same day, be aware that you may feel more drowsy or unsteady than usual. Do not drive or operate machinery if you feel affected. If you experience severe dizziness, chest pain, or an erection lasting more than four hours, seek urgent medical help.

Never take tadalafil if you are also using nitrates (such as GTN spray for angina), nicorandil, riociguat, or recreational drugs called 'poppers', as this combination can cause a dangerous drop in blood pressure [4]. Always tell your prescriber and pharmacist about every medicine you take, including over-the-counter products, herbal remedies, and recreational drugs, so they can check for interactions.

Other medicines that interact with tadalafil

Tadalafil has several important drug interactions that your prescriber must check before approving treatment. Do not take tadalafil with nitrates (GTN spray, isosorbide mononitrate or dinitrate), nicorandil, riociguat, or amyl/alkyl nitrites ('poppers'), as the combination can cause a life-threatening fall in blood pressure [4]. Never take tadalafil with another PDE5 inhibitor such as sildenafil or vardenafil.

Alpha-blockers (doxazosin, tamsulosin, alfuzosin) used for prostate symptoms can also lower blood pressure, so if you take one of these medicines, you should be stable on it before starting tadalafil, and your prescriber will usually recommend the lowest dose [4]. Potent CYP3A4 inhibitors—such as ritonavir, cobicistat, Paxlovid, ketoconazole, itraconazole, and clarithromycin—can raise tadalafil levels in the blood, so your dose may need to be reduced or the combination avoided [4].

CYP3A4 inducers like rifampicin, carbamazepine, phenytoin, and St John's wort can make tadalafil less effective. Grapefruit juice may also raise tadalafil levels and should be avoided. Other blood-pressure medicines can add to the blood-pressure-lowering effect, but this is usually manageable—your prescriber will assess your individual situation during the consultation.

Declaring all your medicines

It is essential to list every medicine you take during your online consultation, including prescription medicines, over-the-counter products, herbal remedies, vitamins, and recreational drugs. Your prescriber and pharmacist will check each one for interactions and contraindications. Do not stop or change any prescribed medicine without speaking to your GP or pharmacist first, even if you think it might interact with tadalafil—there may be safer alternatives or ways to manage the combination.

When to seek medical help and next steps

Seek urgent medical help (call 999 or go to A&E) if you experience an erection lasting more than four hours (priapism), sudden loss of vision or hearing, severe chest pain during sex, or signs of an allergic reaction such as swelling of the face, lips, or throat [4]. If you feel severely dizzy, faint, or unwell after taking tadalafil and temazepam together, sit or lie down and seek medical advice.

If you have new or worsening erectile dysfunction, it is important to see your GP for a full assessment, as ED can be an early warning sign of heart disease, diabetes, or other health conditions [1]. Your GP can check your cardiovascular risk, blood pressure, blood sugar, and cholesterol, and discuss lifestyle changes such as stopping smoking, losing weight, reducing alcohol, and increasing physical activity—all of which can improve erectile function [2].

At Cured Pharmacy, all ED treatments are supplied only after an online consultation reviewed by a UK-registered prescriber. You will be asked about your medical history, current medicines (including temazepam), and any symptoms or conditions that might make tadalafil unsuitable. If approved, your medicine will be dispensed by our GPhC-registered pharmacy and delivered discreetly to your door. If you have any questions or concerns about taking tadalafil and temazepam together, our pharmacist-led team is here to help.

Scientific References

1. NHS. (n.d.). Erectile dysfunction (impotence). NHS website. https://www.nhs.uk/conditions/erection-problems-erectile-dysfunction/ [accessed 26 October 2026]
2. National Institute for Health and Care Excellence. (n.d.). Erectile dysfunction. Clinical Knowledge Summaries. https://cks.nice.org.uk/topics/erectile-dysfunction/ [accessed 26 October 2026]
3. Joint Formulary Committee. (n.d.). Tadalafil. British National Formulary. NICE. https://bnf.nice.org.uk/drugs/tadalafil/ [accessed 26 October 2026]

Information on this page is for educational purposes only and is not medical advice. Prescription treatments require clinical assessment by a UK-registered prescriber. Always consult a qualified healthcare professional before starting or changing any medication.