Cristina Po Wenger
Author: Cristina Po Wenger Medical Reviewer: Dr. Brittany Ferri, PhD Last updated:

Trimipramine, commonly known as Surmontil, is a tricyclic antidepressant medication used to treat depressive disorders in adults. Follow all precautions and take this medication exactly as prescribed to avoid side effects and drug interactions associated with its use.

Trimipramine brand names

Trimipramine is available as a generic or as the brand name Surmontil.

What is trimipramine prescribed for?

The U.S. Food and Drug Administration (FDA) has approved Surmontil, or its generic trimipramine, for treating depressive disorders in adults.

Trimipramine has a sedating effect that can also reduce anxiety symptoms occurring as a part of major depressive disorder.[2] This sedative effect also improves sleep for those who suffer sleep disruption related to depression.

How does trimipramine work?

Experts believe trimipramine increases neurochemicals in the brain associated with depression.[6] Further research is needed to determine precisely how and why trimipramine works to alleviate symptoms of depression.

Those whose depression symptoms include sleep problems, anxiety, irritability, or agitation, are the best candidates for treatment with trimipramine due to its sedating effects.

How is trimipramine usually taken?

Trimipramine is available in capsule form to be taken orally.

Trimipramine is available only by prescription. Follow all instructions from the healthcare provider when taking this medication.

Do not tamper or alter trimipramine capsules by cutting or opening them. Doing so affects the way the medication is absorbed in the body.

Trimipramine may be prescribed up to three times daily. Take doses around the same time(s) each day.

Take missed doses as soon as possible. Skip the missed dose if it is nearly time for the next dose.

Trimipramine should be started at a low dose and gradually increased until reaching clinical benefit to avoid adverse interactions.[2]

Continue taking trimipramine even after symptoms have resolved. Suddenly stopping this medicine can cause unwanted withdrawal symptoms.

Gradually titrating from trimipramine can avoid unwanted withdrawal symptoms. Follow the healthcare provider’s directions when stopping this medication.

The doctor may recommend trimipramine use continue even after symptoms are alleviated to ensure that improvements maintain after its use is stopped.[2]

Stopping this medication too soon can cause depression symptoms to return.

How long does trimipramine stay in your system?

Trimipramine has an approximate half-life of 23 hours. [4]

It is generally agreed that it takes around 5.5 half-lifes for a drug to be fully excreted from a person’s body. [7]

Based on this, it would take around 126 hours, or just over 5 days, for trimipramine to fully leave someone’s system.

Trimipramine side effects

Trimipramine side effects can range from mild to severe. Report all adverse effects to the physician to prevent more serious complications.

Some side effects may resolve on their own the longer trimipramine is taken. Others may require an adjustment to the dosage or a change in medication.

Common side effects of trimipramine include [5][6]:

  • High blood pressure
  • Tingling sensations in the hands or feet
  • Dry mouth
  • Nausea
  • Vomiting
  • Itchiness with or without a rash
  • Breast swelling 
  • Changes in liver functioning
  • Excitability
  • Stomachache
  • Diarrhea or constipation
  • Nightmares
  • Headaches
  • Changes in libido 
  • Tinnitus 
  • Drowsiness 
  • Urinary retention

Trimipramine’s serious side effects include [5][6]:

  • Vision changes – tunnel vision, ocular pain, swelling, halos appearing around lights
  • Light-headedness
  • Chest pain
  • Irregular heart rate or fluttering
  • Slowed speech or difficulty talking 
  • Confusion
  • Unusual thoughts
  • Changes in behavior
  • Seizures
  • Painful urination
  • Bruising
  • Unusual bleeding
  • Involuntary muscle movements or spasms
  • Shuffling walk or changes to gait
  • Jaundice 
  • Mouth sores
  • Cold or flu-like symptoms – fever, chills, or sore throat

Elderly patients may have a higher risk of experiencing confusion, psychosis, or other mood changes while taking trimipramine [2].

Some people may experience worsening depression symptoms or thoughts of suicide when first starting an antidepressant medication like trimipramine. This risk may be higher for adolescents and young adults.

As with any prescription medication, an allergic reaction to trimipramine may occur. Signs of an allergic reaction include:

  • Hives
  • Itchiness
  • Swelling in the mouth, tongue, face, or extremities
  • Fever
  • Irregular heart rate
  • Trouble breathing
  • Throat restriction

If an allergic reaction occurs while taking trimipramine, seek emergency medical attention.

Trimipramine precautions

Trimipramine may not be the right medication for those with certain preexisting conditions or risk factors. 

The doctor will ask for a full medical history before prescribing trimipramine. Additional medical testing, such as lab work or a cardiology evaluation, may be requested to prevent any serious complications from using trimipramine.

Certain other substances, especially those causing drowsiness, should not be taken with trimipramine.

Discuss with the doctor all other medications being taken or that may be taken while taking trimipramine. Include any over-the-counter medications, herbal products, and vitamin supplements.

People who have had an allergic reaction to trimipramine or a similar medication should not take it.

People who have taken a monoamine oxidase inhibitor (MAOI) within the past 14 days should not take trimipramine.

Medical conditions or diseases that carry a higher risk for adverse outcomes with trimipramine use include [6]:

  • Heart conditions or heart disease
  • Prostate problems
  • Kidney problems or kidney disease
  • Liver disease 
  • Seizures
  • Thyroid conditions 
  • Diabetes
  • Bipolar Disorder
  • Schizophrenia 

Trimipramine should only be used with caution and close monitoring by the doctor for those who have suffered a heart attack or have heart disease.[2]

Trimipramine may not be safe for use during pregnancy or while breastfeeding, as there is evidence it could pass on to the fetus or be secreted via breast milk. If pregnant, or planning to become pregnant, discuss these potential risks with the doctor.[6]

Do not suddenly stop taking trimipramine. Suddenly stopping this medication may cause unwanted withdrawal symptoms or worsening depression symptoms.

Trimipramine withdrawal symptoms include [2]:

  • Nausea
  • Headache
  • General feelings of discomfort 

Work with the doctor on a plan for titrating off trimipramine to avoid unpleasant withdrawal symptoms if stopping this medication is necessary.

Notify the surgeon of trimipramine use before undergoing any medical procedures, including dental surgery.

Do not operate heavy machinery, including driving a vehicle, until its effects are known.

Avoid consuming alcohol while taking trimipramine as doing so may worsen drowsiness.

Trimipramine may cause some people to become more sensitive to sunlight. Take precautions to protect the skin and eyes if prolonged sun exposure is necessary.[6]

People with schizophrenia may experience a worsening psychosis from taking trimipramine. Treatment with a lower dosage may reduce this risk.[2]

Trimipramine interactions

Trimipramine and other tricyclic antidepressant drugs are known to interact with certain other pharmaceutical drugs. The doctor must know what other medications are being taken with this medicine.

Be sure that the doctor is aware if you are taking any of the following types of medications [5]:

  • Psychotropics (including other antidepressant medications)
  • Allergy treatments
  • Cold medicines
  • Parkinson’s disease medications
  • Gastrointestinal medications
  • Overactive bladder medications
  • Asthma medicines

Trimipramine use with other types of antidepressant medications such as monoamine oxidase inhibitors (MAOIs) or selective serotonin reuptake inhibitors (SSRIs) can increase the risk of serotonin syndrome [2]. Serotonin syndrome is a potentially life-threatening medical situation caused by serotonin levels being too high in the body.

Signs and symptoms of serotonin syndrome include [2]:

  • Sudden mood changes 
  • Agitation
  • Psychosis including hallucinations, delirium, and delusions
  • Confusion
  • Unstable automatic processes such as heart rate, respiratory rate, and body temperature regulation
  • Seizures
  • Tremors or muscle spasms
  • Loss of coordination
  • Nausea 
  • Vomiting
  • Diarrhea 

If any of these symptoms develop, seek emergency medical care.

Avoid taking other medications that may cause drowsiness or have a sedative quality while taking trimipramine. This includes opioids, muscle relaxers, and prescription or over-the-counter sleeping pills.[5]

Tagamet (cimetidine), an antacid medication, may inhibit the elimination of trimipramine from the body. The doctor will need to monitor the dose if taking trimipramine with cimetidine.[2]

Trimipramine storage

Trimipramine should be stored at room temperature, away from excess moisture and direct light. Keep this medication in a tightly closed container, preferably with child-safety locks.

To avoid accidental ingestion or overdose, keep all prescription medications out of sight and reach of children and pets.

To prevent prescription drug misuse, keep trimipramine out of the reach of adolescents and teenagers. Do not share trimipramine with anyone else.

Avoid flushing this medication down the toilet or disposing of it in garbage receptacles. Ask the doctor or pharmacist about the best way to dispose of unused trimipramine medication.

What to do if you overdose on trimipramine

A trimipramine overdose may be fatal, especially if taken with other substances. If an overdose has occurred or is suspected, immediately seek emergency medical care.

Signs of an overdose with trimipramine are [2]:

  • Cardiac irregularity
  • High blood pressure
  • Seizure
  • Coma or loss of consciousness
  • Confusion
  • Inability to concentrate
  • Hallucinations
  • Dilated pupils
  • Agitation
  • Drowsiness
  • Muscle rigidity
  • Vomiting

The poison control helpline, at 1-800-222-1222, can offer additional information and guidance in case of a trimipramine overdose.


Trimipramine vs Amitriptyline: What’s the difference?

Both trimipramine and amitriptyline are tricyclic antidepressant medications used to treat depression symptoms in adults. These medications are associated with many of the same side effects, risks, and drug interactions.

Some studies suggest that amitriptyline is slightly more effective than trimipramine but that there may be more side effects from taking amitriptyline.[1] Patients who are sensitive to medication side effects may tolerate trimipramine better. 

  1. Rickels, K., BAZILIAN, S. E., GORDON, P. E., WEISE, C. C., Feldman, H. S., & Wilson, D. A. (1970). Amitriptyline and trimipramine in neurotic depressed outpatients: A collaborative study. American Journal of Psychiatry, 127(2), 208-218.
  2. SURMONTIL® (Trimipramine Maleate). (2014, May). U.S. Food And Drug Administration.
  3. Trimipramine 25mg Tablets – Summary of Product Characteristics (SmPC) – (emc). (n.d.). Retrieved November 24, 2022, from
  4. Trimipramine 25mg Tablets – Summary of Product Characteristics (SmPC) – (emc). (n.d.).
  5. Trimipramine. (n.d.).
  6. Trimipramine: MedlinePlus Drug Information. (n.d.).
  7. What do you mean by the half life of a drug? (n.d.-c).
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Cristina Po Wenger
Author Cristina Po Wenger Writer

Cristina Po Wenger is a medical writer and mental health advocate with a Sociology Degree from the University of Stirling.

Published: Nov 22nd 2022, Last edited: Nov 10th 2023

Brittany Ferri
Medical Reviewer Dr. Brittany Ferri, PhD OTR/L

Dr. Brittany Ferri, PhD, is a medical reviewer and subject matter expert in behavioral health, pediatrics, and telehealth.

Content reviewed by a medical professional. Last reviewed: Nov 23rd 2022