Trimipramine belongs to a class of medications called tricyclic antidepressants (TCAs). It is used to treat depression and works by affecting the balance of certain chemicals called neurotransmitters in the brain. It may take several days to several weeks before improvement in symptoms is seen with this medication.

This medication may be available under multiple brand names and/or in several different forms. Any specific brand name of this medication may not be available in all of the forms or approved for all of the conditions discussed here. As well, some forms of this medication may not be used for all of the conditions discussed here.

Your doctor may have suggested this medication for conditions other than those listed in these drug information articles. If you have not discussed this with your doctor or are not sure why you are taking this medication, speak to your doctor. Do not stop taking this medication without consulting your doctor.

Do not give this medication to anyone else, even if they have the same symptoms as you do. It can be harmful for people to take this medication if their doctor has not prescribed it.

The recommended starting dose of trimipramine is 75 mg daily in 2 or 3 divided doses. Your doctor may increase the dose gradually until a response to the medication occurs (this may take a few weeks or more). The dose is then adjusted to control the symptoms with acceptable side effects. The usual maintenance dose is approximately 150 mg to 200 mg daily in divided doses.

Trimipramine may be taken with or without food.

Many things can affect the dose of a medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a dose different from the ones listed here, do not change the way that you are taking the medication without consulting your doctor.

It is important that this medication be taken exactly as prescribed by your doctor. If you miss a dose, take it as soon as possible and continue with your regular schedule. If it is almost time for your next dose, skip the missed dose and continue with your regular dosing schedule. Do not take a double dose to make up for a missed one. If you are not sure what to do after missing a dose, contact your doctor or pharmacist for advice.

Do not take trimipramine if you:

• are allergic to any of the ingredients of the medication
• are allergic to other dibenzazepine-type medications
• are also taking a MAO inhibitor (e.g., phenelzine, tranylcypromine) or have taken one within the last 2 weeks
• have acute congestive heart failure
• have just had a heart attack
• have glaucoma
• have an enlarged prostate gland

Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent. The side effects listed below are not experienced by everyone who takes this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor.

The following side effects have been reported by at least 1% of people taking this medication. Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

• diarrhea
• dizziness
• drowsiness
• dryness of mouth
• headache
• heartburn
• increased appetite (may include a craving for sweets)
• increased sweating
• nausea
• tiredness or weakness (mild)
• trouble sleeping
• unpleasant taste
• vomiting
• weight gain

Although most of the side effects listed below don't happen very often, they could lead to serious problems if you do not seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

Less common:

Rare:

• anxiety
• breast enlargement (both men and women)
• hair loss
• inappropriate secretion of breast milk (women)
• increased sensitivity to sunlight
• irritability
• muscle twitching
• red or brownish spots on skin
• ringing, buzzing, or other unexplained sounds in the ears
• seizures
• skin rash and itching
• sore throat and fever
• swelling of face and tongue
• swelling of testicles
• trouble with teeth or gums
• weakness
• yellow eyes or skin

Stop taking the medication and seek immediate medical attention if any of the following occur:

• seizures
• symptoms of a severe allergic reaction (e.g., swelling of face and tongue, difficulty breathing, hives)

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking this medication.

Before you begin using a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use this medication.

Alcohol and other medications that cause drowsiness: Do not combine this medication with alcohol or other medications (e.g., antidepressants, sleeping pills, anxiety medications) that cause drowsiness because trimipramine can also cause drowsiness and the combination can be dangerous.

Constipation: Trimipramine may cause constipation, especially for seniors.

Mania or hypomania: Trimipramine may cause activation of mania or hypomania. If you experience symptoms such as hallucinations, mania (feeling unusually over-excited or uninhibited), or delusional thinking, or notice them in a family member who is taking this medication, contact your doctor as soon as possible.

People with a history of bipolar disorder should be closely monitored by their doctor while using this medication.

Medical conditions:  If you have a history of seizures, urinary retention, glaucoma, or thyroid disease, let your doctor know before you start this medication. Tricyclic antidepressant medications such as trimipramine, particularly when taken in high doses, can cause abnormal heart rhythms. Therefore, seniors or people with a history of heart disease should be closely monitored by their doctor when taking trimipramine.

Mental and physical impairment: Trimipramine may impair the mental or physical abilities required for the performance of potentially hazardous tasks, such as driving or operating machinery.

Suicidal or agitated behaviour: People taking antidepressants such as trimipramine feel agitated (restless, anxious, aggressive, emotional, trouble sleeping, and feeling not like themselves), or they may want to hurt themselves or others. If you notice any changes in mood, behaviours, thoughts, or feelings in yourself or someone who is taking this medication, contact a doctor immediately. Your doctor will monitor you closely for behaviour changes, especially at the start of treatment or when your dose is increased or decreased.

Withdrawal: Stopping treatment with trimipramine after having taken it for a long period of time may produce nausea, headache, and malaise. These symptoms do not mean that you are addicted to the medication. Do not stop taking trimipramine suddenly without first talking with your doctor.

Pregnancy: The safety of trimipramine for use during pregnancy has not been established. If you are or may be pregnant, the possible benefits of taking this medication must be weighed against the possible risks. If you become pregnant while taking trimipramine, talk to your doctor.

Breast-feeding: The safety of trimipramine for use while breast-feeding has not been established. If you are a breast-feeding mother and are taking trimipramine, it may affect your baby. Talk to your doctor about whether you should continue breast-feeding.  

Seniors: Seniors may be more at risk of experiencing side effects from trimipramine.

There may be an interaction between trimipramine and any of the following:

• abiraterone
• acetylsalicylic acid (ASA)
• aclidinium
• alcohol
• alpha agonists (e.g., clonidine, methyldopa)
• amantadine
• amphetamines (e.g., dextroamphetamine, lisdexamfetamine)
• antihistamines (e.g., azelastine, cetirizine, doxylamine, diphenhydramine, hydroxyzine, loratadine,)
• antipsychotics (e.g., chlorpromazine, clozapine, haloperidol, methotrimeprazine, olanzapine, quetiapine, risperidone)
• apraclonidine
• benzodiazepines (e.g., alprazolam, diazepam, lorazepam)
• benztropine
• beta-2 agonists (e.g., salbutamol, salmeterol, formoterol, terbutaline)
• botulinum toxin-containing products
• brimonidine
• buprenorphine
• bupropion
• buspirone
• butorphanol
• cannabis
• celecoxib
• chloral hydrate
• cinacalcet
• clidinium
• darifenacin
• darunavir
• decongestants (e.g., naphazoline, oxymetazoline, phenylephrine, xylometazoline)
• desmopressin
• dexmethylphenidate
• dextromethorphan
• diabetes medications (sulfonylureas; e.g., gliclazide, glyburide)
• disopyramide
• domperidone
• donepezil
• dronedarone
• eluxadoline
• entacapone
• epinephrine
• ergot alkaloids (e.g., dihydroergotamine, ergonovine, ergotamine, methylergonovine)
• esketamine
• flibanserin
• galantamine
• glucagon
• glycopyrrolate
• iodinated contrast agents
• ipratropium
• ketotifen
• lemborexant
• levodopa
• linezolid
• lithium
• methylene blue
• methylphenidate
• metoclopramide
• mirabegron
• mirtazapine
• monoamine oxidase inhibitors (MAOIs; e.g., moclobemide, phenelzine, rasagiline, selegiline, tranylcypromine)
• muscle relaxants (e.g., baclofen, cyclobenzaprine, methocarbamol, orphenadrine)
• narcotic pain relievers (e.g., codeine, fentanyl, morphine, oxycodone, tapentadol, tramadol)
• nitroglycerin
• non-steroidal anti-inflammatory medications (NSAIDs; e.g., diclofenac, ibuprofen, ketorolac, naproxen)
• oxybutynin
• ozanimod
• pomalidomide
• potassium chloride
• pramipexole
• quinidine
• rivastigmine
• ropinirole
• rotigotine
• St. John's wort
• scopolamine
• seizure medications (e.g., clobazam, ethosuximide, , levetiracetam, phenobarbital, phenytoin, primidone, rufinamide, topiramate, valproic acid, zonisamide)
• selective serotonin reuptake inhibitors (SSRIs; e.g., citalopram, fluoxetine, paroxetine, sertraline)
• serotonin antagonists (anti-emetic medications; e.g., granisetron, ondansetron)
• serotonin/norepinephrine reuptake inhibitors (SNRIs; e.g., desvenlafaxine, duloxetine, venlafaxine)
• sodium phosphates
• terbinafine
• thalidomide
• thiazide diuretics (water pills; e.g., hydrochlorothiazide, indapamide, metolazone)
• thyroid replacements (e.g., desiccated thyroid, levothyroxine)
• tiotropium
• tolterodine
• trazodone
• other tricyclic antidepressants (e.g., clomipramine, desipramine, imipramine)
• "triptan" migraine medications (e.g., eletriptan, rizatriptan, sumatriptan)
• tryptophan
• umeclidinium
• zolpidem
• zopiclone

If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

• stop taking one of the medications,
• change one of the medications to another,
• change how you are taking one or both of the medications, or
• leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with this medication. Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.