Take clonidine exactly as your doctor or pharmacist tells you to. Always follow the instructions that come with the medicine. If you're not sure, check with your doctor or pharmacist.
Dosage and strengths
Clonidine tablets come in 2 strengths: 100 micrograms or 25 micrograms. The liquid contains 50 micrograms in 5ml.
Dose for adults
Your dose of clonidine depends on what you're taking it for.
For preventing migraines or similar types of headaches, or for treating menopausal hot flushes or sweats, the usual dose for adults is 50 micrograms to 75 micrograms twice a day.
For high blood pressure, the usual starting dose for adults is 50 micrograms to 100 micrograms 3 times a day.
Your doctor will tell you how much to take and how often to take it.
Dose for children
The dose for children depends on why they’re taking it, how old they are and how much they weigh. A specialist will advise you on the correct dose.
Changes to your dose
If you're taking clonidine to prevent migraines or for menopausal hot flushes, your dose will usually stay the same as long as it seems to be working well and you are not having too many side effects.
If you're taking clonidine for high blood pressure, your doctor will gradually increase your dose until your blood pressure is under control. The maximum recommended dose is 1.2mg in total per day.
Over time your dose may need to go up or down according to your blood pressure readings.
How to take it
Try to spread the doses out as evenly as possible and take clonidine at the same times each day.
If you take it once a day, you can take it in the morning or the evening. But because clonidine can make you feel sleepy, you may prefer to take it around bedtime.
If you take it twice a day, take the first dose in the morning and the second dose in the evening. It's best to leave about 10 to 12 hours between doses.
If you take it 3 times a day, take the first dose in the morning, the second dose early afternoon and the third dose at bedtime. It's best to leave about 6 to 8 hours between doses.
Swallow the tablets whole with a drink of water. You can take clonidine with or without food.
The 100 microgram tablets can be cut in half if you need a 50 microgram dose but you do not have any 25 microgram tablets. Talk to your pharmacist about how to do this. It's best to use a special tablet-cutting device, available to buy in pharmacies.
Liquid clonidine should come with a plastic syringe or spoon to help you measure out the right dose. If you do not have a syringe or spoon, ask your pharmacist for one. Do not use a kitchen teaspoon as it will not measure the right amount.
How long to take it for
How long you'll take clonidine for depends on why you're taking it. For most conditions you'll need to keep taking clonidine for as long as it's working for you and you still need it. Some people take it for many months and even for years.
Do not stop taking clonidine suddenly as this can cause dangerously high blood pressure and withdrawal side effects.
If you take clonidine for high blood pressure, you'll probably need to take it for the rest of your life to protect against the risks of high blood pressure, such as heart attacks and strokes.
Keep taking it regularly, even if you feel well.
If you forget to take it
If you or your child forgets a dose of clonidine, take it as soon as you remember, unless it's nearly time for your next dose. In this case, skip the missed dose and take your next dose at the usual time.
Never take 2 doses at the same time. Never have an extra 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 medicines.
If you take too much
Taking too much clonidine can cause:
- low blood pressure – this might make you faint feel dizzy
- a slow heart rate
- sleepiness
- breathing difficulties
- being sick
- small pupils in your eyes
- dry mouth
Urgent advice: Contact 111 for advice now if:
- you or your child has taken more than your prescribed dose of clonidine
Go to 111.nhs.uk or call 111. Call 111 if you're asking about a child under the age of 5 years.
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 clonidine packet, or the leaflet inside it, plus any remaining medicine with you.
Stopping clonidine
Whatever you're taking clonidine for, stopping it suddenly can cause a dangerous increase in your blood pressure. It can also cause withdrawal side effects such as restlessness, heart palpitations, agitation, nervousness, tremor or shaking hands, headaches or feeling sick (nausea).
Do not stop taking clonidine without talking to a doctor. If you need to stop taking it, you'll need to reduce your dose gradually. Your doctor can advise you how to do this safely.