Tricyclic Antidepressants (TCAs)

Amitriptyline and imipramine

Amitriptyline and imipramine are tricyclic antidepressants (TCAs).

They can help neuropathic (nerve) or widespread pain, such as fibromyalgia. They may help improve sleep quality. Imipramine is less sedating than amitriptyline.

You have not been prescribed this medication for depression. The dose use for pain is much lower. Caution is needed if TCAs are prescribed along with other antidepressants.

What dose should I take?

The dose prescribed will vary from person to person. Know your prescribed dose and never take more than recommended.

Start at 10mg at night. Take it 10-12 hours before your usual wake up time. If you get up at 7 AM, take it between 7-9 PM.

You may be advised to continue increasing weekly until you reach a dose that helps with pain or sleep without causing side effects.

Week 1: One 10mg tablet each night.

Week 2: Two 10mg tablets each night.

Week 3: Three 10mg tablets each night.

It can take 4-6 weeks to gain the best effect.

The usual maximum dose for pain is 75mg at night. Often lower doses give benefit. Higher doses cause more side effects.

The tablets come in different strengths including 10mg and 25mg.

What are the side effects?

All medicines can cause side effects. Not everyone will get them. Read the information sheet given with the medicine.

Common side-effects include: drowsiness, dizziness, dry mouth, constipation and sweating.

Less common side effects include: fainting, trembling, irregular heartbeat, blurred vision, problems passing urine.

If the medicine makes you sleepy, do not driving or operating machinery. It is an offence to do so whilst unsafe due to medicines. Alcohol may make the sleepiness worse.

Some side effects can be reduced by slowly building up the dose. Others may pass after the first few doses. Talk to a doctor or pharmacist about any problems.

How long should I take amitriptyline or imipramine for?

It can be taken for as long as it is helping and not causing problems. Review will help to decide this.

Review is recommended every few weeks or months when starting. Then at least every 6-12 months.

After a while medicine may not work as well. Or it may no longer be needed. Talk to a doctor or pharmacist if you have concerns.

How do I reduce the dose?

Do not stop amitriptyline or imipramine suddenly, as this may cause withdrawal effects. Reducing the dose slowly can prevent these effects. A doctor or pharmacist can advise.

A reduction in 10mg steps is often recommended. This can be done every 1 or 2 weeks and be continued until the medicine is stopped.

Let you doctor know if

• You are planning to get pregnant, pregnant or breastfeeding.

Medication in chronic pain

• Medicines are not always helpful for long term pain.
• They can cause side effects and harm.
• It is best to stop medicines that are not working or cause problems.
• It is helpful to find other ways of managing pain.
• A doctor or pharmacist can explain more.

Remember

• Do not stop medicines suddenly.
• Do not share medicines.
• Never take more medicine than prescribed.
• Let a doctor or pharmacist know about other medicines or products taken.
• Read the information sheet given with each medicine.
• Keep medicines out of the reach of children.
• Store medicines safely.
• Return unused medicines to a pharmacy.
• If medicines make you drowsy, do not drive.
• Talk to a doctor or pharmacist about any concerns.