Imipramine

What is imipramine?

Imipramine belongs to a group of medicines called tricyclic antidepressants. In the past, these medicines were commonly used for depression, but today doctors usually prescribe newer classes of antidepressants. Tricyclic antidepressants are used for severe depression or when other antidepressants are unsuitable. Read more about antidepressants.

Imipramine is also used to treat night-time bed wetting in older children if they have already tried other treatments without success. Read more about bed wetting in children. 

In New Zealand, imipramine is available as tablets in different strengths - 10 mg and 25 mg.

Dose

• The dose of imipramine will be different for different people.
• For depression: your doctor will usually start you on a low dose and increase this slowly. This allows your body to get used to the medicine and reduces side effects. Imipramine may be prescribed as a single dose to be taken at bedtime, or it may be prescribed in smaller doses taken two or three times a day.
• For bed wetting: imipramine is given once each day, in the evening. 
• Always take your imipramine exactly as your doctor has told you. The pharmacy label on your medicine will tell you how much imipramine to take, how often to take it, and any special instructions.
• If your tablets look different to your last supply, ask your doctor or pharmacist for advice.

How to take imipramine

• Take imipramine at the same times each day. 
• Swallow your imipramine tablets with a glass of water.
• You can take imipramine with or without food.
• Keep taking imipramine every day. It may take a few weeks before you notice the full benefits of imipramine.
• If you think imipramine is not working for you, do not stop taking it suddenly; speak to your doctor or nurse before stopping.

Missed dose

If you forget to take your dose:

• For depression: take it as soon as you remember. But, if it is nearly time for your next dose, just take the next dose at the right time. Do not take double the dose.
• For bed wetting: you do not need to wake your child up to give the missed dose. It is likely to make your child sleepy so it may be better to forget the missed dose altogether and give the next evening dose as usual.

Precautions before starting imipramine

• Have you recently had a heart attack?
• Do you have problems with your heart rhythm?
• Do you have diabetes?
• Do you have problems with your kidneys or liver?
• Do you have glaucoma?
• Do you have problems with your thyroid?
• Do you have bipolar disorder?
• Do you have epilepsy?
• Do you have problems passing urine or problems with your prostate?
• Do you have problems with constipation?
• Are you pregnant or breastfeeding?
• Are you taking any other medicines, including medicines you can buy without a prescription, such as herbal and complementary medicines?

If any of these apply, it’s important that you tell your doctor or pharmacist before you start imipramine. Sometimes a medicine isn’t suitable for a person with certain conditions, or it can only be used with extra care.

Precautions while taking imipramine

• Alcohol: avoid alcohol while you are taking imipramine, especially when you first start treatment. Drinking alcohol while taking imipramine can cause drowsiness and affect concentration, putting you at risk of falls and other accidents. It can also cause agitation, aggression and forgetfulness. If you do drink alcohol, drink only small amounts and see how you feel. Do not stop taking your medication.
• Diabetes: if you have diabetes, you may need to check your blood glucose more often because imipramine can affect the levels of glucose in your blood. 

What are the side effects of imipramine?

Like all medicines, imipramine can cause side effects, although not everyone gets them. Often side effects improve as your body gets used to the new medicine.

Suicidal behaviour

The use of antidepressants has been linked with self-harm or suicidal thoughts and behaviour. Children, teenagers, young adults and people with a history of suicidal behaviour are most at risk. This is most likely during the first few weeks of starting treatment or if the dose is changed. It is important to look out for signs of suicidal behaviour such as suicidal thoughts, self-harm, worsening of low mood, agitation or aggression.

If you notice any of these signs, contact your doctor immediately. If you need urgent help or are concerned, phone:

• Lifeline 0800 543 354 (available 24/7), or
• Healthline 0800 611 116, who can give you the phone number for your local mental health crisis line.

Other side effects

Interactions

Imipramine interacts with many other medications and herbal supplements (such as St. John's Wort) so check with your doctor or pharmacist before starting imipramine or before starting any new medicines.

Learn more

The following links have more information on imipramine.

Medsafe Consumer Information Sheets: Tofranil  
New Zealand Formulary Patient Information: imipramine

References

1. Imipramine hydrochloride New Zealand Formulary
2. The role of medicines in the management of depression in primary care BPAC, 2017