Follow your doctor's advice, and the instructions that come with your medicine.
Dosage
The usual starting dose for mirtazapine is 15mg to 30mg a day. This can be increased to up to 45mg a day.
Your doctor may recommend dividing your daily dose into 2 doses of different sizes.
If you have problems with your liver or kidneys your doctor might prescribe a lower dose.
How to take it
You can take mirtazapine with or without food.
Swallow the tablets whole with a drink of water. Do not break, crush or chew them.
Mirtazapine also comes as tablets that melt in your mouth (orodispersible tablets). Put the tablet on your tongue and let it dissolve. You can then swallow it without a drink.
Liquid mirtazapine will 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.
You'll usually take mirtazapine once a day. It's best to take it before you go to bed as it can make you sleepy.
If your doctor tells you to take it twice a day, take the smaller dose in the morning and the higher dose before you go to bed.
How long to take it for
Once you're feeling better you're likely to keep taking mirtazapine for several more months.
Most doctors recommend that you take antidepressants for 6 months to a year after you no longer feel depressed.
Stopping your medicine too soon can make depression come back.
If you forget to take it
If you take mirtazapine once a day and miss a dose, skip the missed dose and take the next dose at the usual time. Do not take a double dose to make up for a forgotten dose.
If you take mirtazapine twice a day and forget:
- your morning dose – take it together with your evening dose
- your evening dose – do not take it with the next morning dose. Instead skip the missed dose, and then continue the next day with your usual morning and evening doses
- both doses – skip the missed doses. Continue the next day with your usual morning and evening doses. Do not take an extra dose to make up for a missed dose
If you often forget doses, 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.
If you take too much
Taking more than your prescribed dose of mirtazapine can cause problems. You may get symptoms including:
- feeling sleepy
- a fast or irregular heartbeat
- feeling confused or faint
The amount of mirtazapine that can lead to an overdose varies from person to person.
Urgent advice: Contact 111 for advice now if:
- you've taken more than your prescribed dose of mirtazapine
Get help from 111 online or call 111
If you need to go to A&E, do not drive. Ask someone to drive you or call 999 and ask for an ambulance.
Bring the mirtazapine packet or leaflet inside it, any remaining medicine, and any other medicines you take.
Stopping mirtazapine
If you've been feeling better for 6 months or more, your doctor may suggest coming off mirtazapine.
Your doctor may recommend reducing your dose gradually over several months, or longer if you've been taking mirtazapine for a long time.
This is to help prevent you getting any extra side effects as you come off the medicine.
Important
Do not stop taking mirtazapine suddenly, or without talking to your doctor first.