Valsartan: uses, side effects and cautions

Valsartan is mainly used to manage high blood pressure and is also used to help treat heart failure. It is an angiotensin receptor blocker and is available only on prescription. The NHS page does not give a brand name or say how quickly it takes effect.

Most adults aged 18 or over can take valsartan, and it may suit children aged 6 to 17. It is unsuitable if you have had an allergic reaction or serious side effect from another ARB, if you have severe heart failure, if you have liver or kidney problems, or if you have a history of angioedema, which is sudden swelling of the body. It is not usually used in pregnancy or during breastfeeding.

It comes as tablets, capsules or a liquid. Most people take it once or twice a day, at any time of day but at the same time each day, with water and with or without food. The NHS gives no fixed dose figures, and your dose may be adjusted after several weeks.

Treatment is usually long term, and the NHS is clear that you should not stop unless your doctor tells you to. Missed a dose? Take the next one as normal; do not double up. Taking too much can be dangerous: call NHS 111, and use 999 if you need emergency transport.

Your doctor will arrange blood tests and blood pressure checks to see how valsartan is affecting your pressure and your kidneys.

Common effects include dizziness, headache, tummy pain, tiredness, nausea and vomiting. Speak to a pharmacist or doctor if they bother you, and keep taking the tablets unless advised to stop.

Serious effects are uncommon but include anaphylaxis with a swollen throat or tongue, liver problems with yellow skin and eyes, a fast or irregular heartbeat that feels like pounding or fluttering, and high potassium causing muscle weakness or twitching. Call 999 for suspected anaphylaxis and NHS 111 for the others.

Because the tablets, capsules and liquid are different products, check which one you were handed and read the leaflet that comes with it. A sensible habit is to keep a short list of every medicine you take, including pharmacy purchases, and show it to anyone who prescribes something new.

If you are dehydrated through illness, or a pharmacist offers an anti-inflammatory painkiller, mention valsartan first. Neither is a reason to stop the tablets on your own, but both are reasons to ask before carrying on unchanged.

The NHS names other blood pressure medicines including ACE inhibitors such as lisinopril, diuretics such as spironolactone, NSAIDs including ibuprofen, and lithium. Potassium supplements and potassium-containing salt substitutes can push potassium too high.

Drinking too much alcohol can cause dizziness, light-headedness and dehydration. Valsartan should not affect driving or machinery, but if you feel dizzy or tired, wait until it passes.

Valsartan is not usually used in pregnancy, and your doctor may offer different treatment. It is also not usually used while breastfeeding. Tell your doctor if you are pregnant, planning a pregnancy or nursing. The NHS points to the Bumps website for details about ARBs in pregnancy.

Losartan, candesartan and irbesartan are related ARBs, and ACE inhibitors such as ramipril are another class. Side effects can be reported through the Yellow Card scheme.