Always take olmesartan as instructed by your doctor.
Dosage and strength
Olmesartan comes as 10mg, 20mg and 40mg tablets.
For adults and children aged 6 years and over, the usual starting dose is 10mg taken once a day.
Your dose may go up to 20mg or 40mg, taken once a day.
Children weighing less than 35kg (about 5.5 stone) should not take more than 20mg daily.
Changes to your dose
After a few weeks your doctor will check your blood pressure and ask you if you're getting any side effects.
You may also have blood tests to check how well your kidneys are working and the amount of potassium in your blood.
Your doctor will then decide whether to change your dose of olmesartan.
If olmesartan does not bring your blood pressure down, your doctor may want to increase the dose.
If your blood pressure gets too low or you get side effects, your doctor may want to lower your dose.
How to take it
Take olmesartan tablets once a day. Swallow the tablets whole with a drink of water. Do not crush or chew them.
You can take olmesartan with or without food.
Your doctor may suggest that you take your first dose before bedtime, as it can make you feel dizzy. After the first dose, you can then take olmesartan at any time of day.
Usually people take olmesartan in the morning, but it does not really matter. Just try to take it at the same time every day.
Speak to a pharmacist if you or your child have difficulty swallowing tablets.
How long to take it for
Usually treatment with olmesartan is long term, even for the rest of your life.
If you get ill while taking it
If you get severe diarrhoea or vomiting for any reason, contact your doctor or a pharmacist. They'll be able to advise you about what to do.
They may lower your dose or recommend that you stop taking olmesartan until you're better and able to eat and drink normally again.
If you take contraceptive pills and you're being sick (vomiting) or have severe diarrhoea for more than 24 hours, your contraception may not protect you from pregnancy. Check the pill packet to find out what to do.
If you forget to take it
If you miss a dose of olmesartan, take it as soon as you remember if it's the same day. If you do not remember until the next day, skip the forgotten dose and take your next dose at the usual time.
Do not take a double dose to make up for a forgotten one.
If you forget doses often, it may help to set an alarm to remind you. You could also ask your pharmacist for advice on other ways to help you remember to take your medicine.
Stopping olmesartan
Talk to your doctor if you want to stop taking olmesartan.
Stopping olmesartan may cause your blood pressure to rise. This may increase your chances of having a heart attack or stroke.
If you're bothered by side effects, your doctor may be able to prescribe a different blood pressure-lowering medicine.
Important
Take olmesartan even if you feel well, as you'll still be getting the benefits of the medicine.
If you take too much
Taking too much olmesartan can make you feel dizzy (due to low blood pressure).
The amount of olmesartan that can lead to an overdose varies from person to person.
Urgent advice: Contact 111 for advice now if:
- you take more than your prescribed dose of olmesartan
Go to 111.nhs.uk or call 111.
If you need to go to A&E, do not drive yourself. Get someone else to drive you or call for an ambulance.
Take the olmesartan packet or the leaflet inside it, plus any remaining medicine, with you.