Losartan potassium/hydrochlorothiazide 100/25 mg tablets: uses and side effects
Quick summary Losartan potassium/hydrochlorothiazide 100/25 mg is a combination tablet used for essential hypertension (high blood pressure). It combines an angiotensin II receptor blocker with a thiazide diuretic to help lower blood pressure when...
This content is for educational purposes only and does not replace medical advice, diagnosis or treatment from a qualified healthcare professional.
Quick summary
Losartan potassium/hydrochlorothiazide 100/25 mg is a combination tablet used for essential hypertension (high blood pressure). It combines an angiotensin II receptor blocker with a thiazide diuretic to help lower blood pressure when a single medicine is not enough.
Medical disclaimer: This article is for general information only and does not replace advice from a doctor, pharmacist, or the official patient leaflet. Do not use it to diagnose a condition or to change your treatment plan.
What is losartan potassium/hydrochlorothiazide 100/25 mg?
Losartan potassium/hydrochlorothiazide 100/25 mg film-coated tablets are a fixed-dose combination medicine used mainly to treat essential hypertension. Each tablet contains 100 mg of losartan and 25 mg of hydrochlorothiazide.
Losartan blocks the effects of angiotensin II, a substance that narrows blood vessels. Hydrochlorothiazide is a thiazide diuretic that helps the body remove extra salt and water. Together, they can help lower blood pressure.
What is it used for?
The main use of this medicine is the treatment of high blood pressure. It may be prescribed when blood pressure is not adequately controlled with a single medicine.
- Management of essential hypertension
- Blood pressure control when combination treatment is needed
- Support for reducing long-term risks linked to uncontrolled hypertension
Blood pressure treatment is individualised. A doctor or pharmacist can confirm whether this strength is appropriate for a specific prescription.
How does the combination work?
Losartan and hydrochlorothiazide work in different ways:
- Losartan helps relax blood vessels.
- Hydrochlorothiazide helps reduce fluid volume by increasing urine output.
This dual action is why the combination may be used when one medicine alone has not provided enough control.
Possible side effects
Like all medicines, this combination can cause side effects. Not everyone will experience them.
Side effects mentioned in the source content include:
- Dizziness
- Fatigue
- Respiratory infections
- Kidney-related problems
- Electrolyte imbalances
Allergic reactions can also occur. Seek urgent medical help if there is swelling of the face, tongue, or throat, or if rash and itching are severe.
Precautions and monitoring
Before taking this medicine, a healthcare professional should know about any history of kidney or liver problems. Monitoring of blood pressure, kidney function, and electrolytes may be recommended during treatment.
Extra caution may be needed if dehydration is possible, such as during hot weather, prolonged exercise, or illness causing fluid loss.
It is also important to review all other medicines and supplements with a pharmacist or doctor, especially products that may affect kidney function or potassium levels.
Who should not use it?
The source content states that this medicine is contraindicated in people with severe renal or hepatic impairment and in those with a known hypersensitivity to any component.
It also notes that coadministration with aliskiren in diabetic patients is not recommended.
Because suitability depends on the full medical history, the official leaflet and prescriber advice should always be checked.
Pregnancy and fetal safety
This medicine is described as contraindicated during pregnancy because of the risk of fetal toxicity, especially in the second and third trimesters.
Anyone who is pregnant, planning a pregnancy, or thinks they may be pregnant should speak to a healthcare professional promptly. The source content also notes that effective contraception may be advised while taking this medicine.
How is it usually taken?
The medicine is generally taken once daily, with or without food, and at the same time each day. The source content notes that the full 100/25 mg strength may be used after a lower starting dose if needed, but the exact regimen should be followed as prescribed.
Do not change the dose or stop treatment without medical advice.
What to check with a doctor or pharmacist
If you are reviewing this medicine, it can help to confirm the following:
- Whether the prescribed strength matches the intended treatment plan
- Whether any kidney, liver, or electrolyte monitoring is needed
- Whether other medicines could interact with this combination
- Whether pregnancy-related precautions apply
- How and when the tablets should be taken
Frequently asked questions
▸ What is losartan HCTZ 100/25 mg used for?
It is mainly used to treat high blood pressure. The combination is used when blood pressure needs more than one medicine to be controlled.
▸ What is the best time of day to take losartan hydrochlorothiazide?
The source content says it is often taken in the morning to help avoid nighttime urination. Follow the timing given by the prescriber.
▸ What should not be taken with losartan and hydrochlorothiazide?
The source content highlights caution with medicines that may affect kidney function or potassium levels, including some diuretics, potassium supplements, and NSAIDs. Always check with a pharmacist before adding anything new.
▸ Is losartan potassium the same as losartan?
Yes. The source content explains that losartan potassium refers to the potassium salt form of losartan.
▸ Can this medicine be used in pregnancy?
The source content says it should not be used during pregnancy because of fetal toxicity risk. A healthcare professional should be contacted if pregnancy is possible or confirmed.
Safety reminder
If you have symptoms such as severe dizziness, swelling, breathing difficulty, or signs of an allergic reaction, seek urgent medical help. For all other questions about this medicine, check the patient leaflet or speak with a doctor or pharmacist.
Medical disclaimer
This content is for educational purposes only. It should not be used as a substitute for professional medical advice, diagnosis or treatment. Always ask a doctor, pharmacist or qualified healthcare professional before starting, stopping or changing any medicine.
Sources and verification
The following sources or official references are listed to support verification of the medicine information discussed in this article.
Medicine information can change and may vary depending on country, product formulation, patient history and professional guidance. Always check official medicine information and ask a healthcare professional for personal medical questions.