Common questions about olmesartan

Olmesartan is a type of medicine called an angiotensin receptor blocker (ARB) or angiotensin receptor antagonist.

Like other angiotensin receptor blockers, olmesartan relaxes and widens your blood vessels.

This lowers your blood pressure and makes it easier for your heart to pump blood around your body.

It usually takes about a week for olmesartan to start reducing high blood pressure.

It may take 2 to 8 weeks to take effect fully.

If you have high blood pressure, you may not have any symptoms. In this case, you may not feel any different when you take olmesartan.

This does not mean that it is not working. It's important to keep taking your medicine.

Olmesartan is generally safe to take for a long time. In fact, it works best when you take it for a long time.

Taking olmesartan for a long time can sometimes cause your kidneys not to work as well as they should. Your doctor will check how well your kidneys are working with regular blood tests.

Even if olmesartan has successfully lowered your blood pressure, it's best to carry on taking it.

If you stop taking olmesartan, your blood pressure could go back up again.

If you need to take medicine to lower your blood pressure, you'll probably need to take it for the rest of your life.

Remember, by keeping your blood pressure low, you're protecting yourself against having a heart attack or stroke in the future.

Olmesartan works as well as other angiotensin receptor blockers (ARBs) such as candesartan, losartan and valsartan when it's used to lower blood pressure. Its side effects are also similar.

It also works as well as ramipril and other angiotensin converting enzyme (ACE) inhibitors to lower blood pressure.

Olmesartan can be used by people who have tried taking ramipril or other ACE inhibitors but had to stop taking them because the medicine gave them a dry, irritating cough.

There are also lots of other types of blood pressure-lowering medicines, such as:

• calcium-channel blockers like amlodipine
• ACE inhibitors like ramipril
• beta blockers like bisoprolol
• tablets which make you pee more (diuretics) like bendroflumethiazide
• alpha blockers like doxazosin

The medicine you're prescribed depends on your age and ethnicity:

• if you're under 55 and not of African Caribbean or Black African origin you'll usually be offered an ACE inhibitor or an angiotensin receptor blocker
• if you're aged 55 or older, you'll usually be offered a calcium channel blocker
• if you're of African Caribbean or Black African origin, you'll usually be offered a calcium channel blocker whatever age you are

Many people need to take a combination of different blood pressure-lowering medicines.

But taking ARBs and ACE inhibitors together is not usually recommended.

If you're going to be put to sleep (have a general anaesthetic) for an operation or dental procedure, tell the doctor or dental surgeon that you're taking olmesartan.

This is because general anaesthetics can reduce your blood pressure.

Your doctor or dental surgeon will probably advise you to stop taking olmesartan 24 hours before surgery.

There's some evidence that olmesartan might help prevent migraines. But olmesartan is not officially approved for migraines.

Your doctor would probably advise you to try other medicines first.

There have been some studies looking into whether blood pressure medicines could help protect people against Alzheimer's disease.

But at the moment there's not enough evidence to recommend taking olmesartan or other similar medicines for Alzheimer's disease.

There are steps you can take that may reduce your risk of Alzheimer's.

If you're worried about getting Alzheimer's disease in the future or have a family history of this condition, speak to your doctor.

No, olmesartan will not affect any type of contraception, including emergency contraception.

But some types of hormonal methods of contraception, like the combined pill, progestogen-only pill or contraceptive patch, are not usually recommended if you have high blood pressure.

Talk to your doctor if you're taking or using combined hormonal contraceptives.

However, if you are being sick or have severe diarrhoea for over 24 hours while taking olmesartan, your contraception may not protect you from pregnancy. If this happens, follow the instructions in the leaflet that comes with your contraceptive pills.

Find out more:

• What to do if you're sick or have diarrhoea when taking the combined pill
• What to do if you're sick or have diarrhoea when taking the progestogen-only pill

Olmesartan can make some people feel dizzy, especially when they first start taking it or after taking a bigger dose.

If this happens to you, do not drive a car, ride a bike, or use tools or machinery until you feel better.

It's an offence to drive a car if your ability to drive safely is affected. It's your responsibility to decide if it's safe to drive. If you're in any doubt, do not drive.

Talk to your doctor or pharmacist if you're unsure whether it's safe for you to drive while taking olmesartan. GOV.UK has more information on the law on drugs and driving.

Yes, but be careful as drinking alcohol can increase the blood pressure-lowering effect of olmesartan, which can make you feel dizzy or light-headed.

During the first few days of taking olmesartan or after a dose increase, it's best not to drink alcohol until you see how the medicine affects you.

If you find olmesartan makes you feel dizzy, it's best to stop drinking alcohol.

Do not use salt substitutes such as Lo-Salt. This is because they are high in potassium.

When mixed with olmesartan, they may make the level of potassium in your blood too high.

Apart from not drinking too much alcohol, there's nothing else you need to avoid while taking olmesartan.

Eating a healthy, balanced diet can help if you have high blood pressure or heart failure.

You can boost the health of your heart by making some key lifestyle changes.

These will also help if you have high blood pressure or angina:

• Quit smoking – smoking increases your heart rate and blood pressure. Quitting smoking brings down your blood pressure and relieves heart failure symptoms. Try to avoid second-hand smoke.
• Cut down on alcohol – drinking too much alcohol raises blood pressure over time and also makes heart failure worse. Men and women should not drink more than 14 units of alcohol a week. A standard glass of wine (175ml) is 2 units. A pint of lager or beer is usually 2 to 3 units of alcohol.
• Exercise – regular exercise lowers blood pressure by keeping your heart and blood vessels in good condition. It does not need to be too energetic. Walking every day will help.
• Eat well – aim to eat a diet that includes plenty of fruit and vegetables, wholegrains, fat-free or low-fat dairy products and lean proteins. It's a good idea to follow these tips for a lower salt diet, too. Eating too much salt is the biggest cause of high blood pressure. The more salt you eat, the higher your blood pressure will be. Aim for no more than 6g of salt a day.
• Deal with stress – when you're anxious or upset, your heart beats faster, you breathe more heavily and your blood pressure often goes up. This can make heart failure worse, too. Find ways to reduce stress in your life. To give your heart a rest, try napping or putting your feet up when possible. Spend time with friends and family to be social and help avoid stress.
• Vaccinations – if you have heart failure, it's recommended that you have the flu vaccine every year and the pneumococcal vaccine as recommended by your GP. Ask your doctor about these vaccinations. You can have them free on the NHS. The coronavirus (COVID-19) vaccine is recommended for most people. Make sure you've had all the doses that you are eligible for. Talk to your doctor if you think you might be in one of the high risk groups.