Can I take Doxadura and Losartan together?
Drug interaction guide
Originally published 25 Jan 2026
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Taking these two medicines together can cause your blood pressure to drop lower than intended. This may make you feel dizzy, light-headed, or faint, especially when you stand up quickly from a sitting or lying position.
Why this happens
Both Doxadura (doxazosin) and losartan are used to lower blood pressure, but they work in different ways. When used together, their effects add up (an additive effect), which can sometimes lower blood pressure too much.
What you should do
You can take these together, but you should be careful. When you first start this combination or if your dose is increased, get up slowly from a bed or chair to avoid dizziness. It is a good idea to monitor your blood pressure at home and let your doctor know if you feel very dizzy or if your readings are consistently low.
Important precautions
Pregnancy
You must not take losartan if you are pregnant or planning to become pregnant, as it can cause serious harm or death to an unborn baby. Use effective contraception while taking it.
First-dose hypotension
Doxadura can cause a sudden drop in blood pressure, especially after the very first dose. This may make you feel dizzy or faint when standing up. It is recommended to take your first dose at bedtime to avoid falls.
Cataract surgery
If you are due to have eye surgery for cataracts, you must tell your surgeon you are taking Doxadura. It can cause a complication called 'Floppy Iris Syndrome' which the surgeon needs to prepare for.
Food and drink warnings
Alcohol
It is best to avoid or strictly limit alcohol while taking these medicines. Both Doxadura and Losartan lower your blood pressure; alcohol also has this effect. Combining them can make you feel very dizzy, lightheaded, or faint, especially when standing up. It also increases the risk of falls.
Potassium-rich foods and Salt Substitutes
Losartan can increase the levels of potassium in your blood. You should avoid using salt substitutes (such as Lo-Salt) that contain potassium. You should also avoid consuming excessive amounts of potassium-rich foods (such as bananas, spinach, or coconut water) unless specifically advised by your doctor, as high potassium levels can affect your heart rhythm.
Using other medicines
Taking multiple medicines? Our Medicines Interaction Checker helps you check whether your prescriptions, over-the-counter medicines, and supplements are safe to take together. Simply search for your medicines to see potential interactions and what to do about them.
Disclaimer
This information is for general educational purposes only and should not be relied upon as a substitute for professional medical advice. Always consult your GP, pharmacist, or another qualified healthcare professional before making decisions about your medications. Individual circumstances may vary, and only a healthcare professional who knows your medical history can provide personalised guidance.
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Article history
The information on this page is written and peer reviewed by qualified clinicians.
Article also available in English, German, Spanish, French, Italian, Portuguese, Hindi, Hebrew, Arabic, and Swedish.
25 Jan 2026 | Originally published
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