Side Effects of Surmontil (trimipramine)

Surmontil (trimipramine) is a tricyclic antidepressant (TCA) used to treat major depression. Surmontil raises the brain’s level of the neurotransmitter norepinephrine to normal levels and has anti-cholinergic actions, causing side effects. Surmontil also acts as a sedative.

Common side effects of Surmontil include:

• anti-cholinergic effects(confusion, delirium, short-term memory problems, disorientation, impaired attention, dry mouth, constipation, difficulty urinating (especially in men with enlarged prostates), blurred vision, decreased sweating with increased body temperature, sexual dysfunction, worsening of glaucoma)
• increased sensitivity to sunlight.

Discontinuing Surmontil abruptly can cause withdrawal symptoms such as

Serious side effects of Surmontil include

• impaired mental and/or physical abilities required for potentially hazardous tasks such as driving a car or operating machinery
• increased risk of seizures in patients with seizures
• increased risk of suicidal thinking and behavior in children and adolescents with depression and other psychiatric disorders.

Surmontil interacts with other medications and drugs that slow the brain’s processes, such as

Reserpine when taken with Surmontil can cause a stimulatory effect.

Surmontil and other TCAs should not be used with monoamine oxidase inhibitors (MAOIs) because it may result in high fever, convulsions, and death.

Surmontil affects heart rhythm and should not be administered with

• amiodarone,
• sotalol,
• quinidine,
• procainamide, and
• other drugs that affect heart rhythm.

Safe use of Surmontil during pregnancy or lactation has not been established. Consult your doctor before breastfeeding.

Important Side Effects of Surmontil (trimipramine)

Trimipramine impairs the mental and/or physical abilities required for potentially hazardous tasks such as driving a car or operating machinery. The anti-cholinergic effects of trimipramine may cause:

• confusion,
• delirium,
• short-term memory problems,
• disorientation,
• impaired attention,
• dry mouth,
• constipation,
• difficulty urinating (especially in men with enlarged prostates),
• blurred vision,
• decreased sweating with increased body temperature,
• sexual dysfunction,
• worsening of glaucoma.

Older adults are especially sensitive to the anti-cholinergic effects of trimipramine.

Hard candy or chewing gum can prevent dry mouth.

Trimipramine can increase sensitivity to sunlight; patients taking trimipramine should wear sunscreen and avoid sun exposure.

Due to its impact on sweating and adaptation to hot environments, patients should avoid saunas and excessive heat.

Trimipramine should be used with caution in patients with seizures.

If trimipramine is discontinued abruptly, headache, nausea, and general discomfort may occur. Therefore, it is recommended to reduce the dose of antidepressant gradually when therapy is discontinued.

Antidepressants increase the risk of suicidal thinking and behavior in children and adolescents with depression and other psychiatric disorders. Patients who start therapy should be closely observed for clinical worsening, suicidal thinking or behavior, and unusual changes in behavior.

List of Side Effects of Surmontil (trimipramine) for Healthcare Professionals

Note: The pharmacological similarities among the tricyclic antidepressants require that each of the reactions be considered when Surmontil is administered. Some adverse reactions included in this listing have not been reported with Surmontil.

Cardiovascular

Psychiatric

Confusional states (especially in the elderly) with hallucinations, disorientation, delusions; anxiety, restlessness, agitation; insomnia and nightmares; hypomania; exacerbation of psychosis.

Neurological

Numbness, tingling, paresthesias of extremities; incoordination, ataxia, tremors; peripheral neuropathy; extrapyramidal symptoms; seizures, alterations in EEG patterns; tinnitus; syndrome of inappropriate ADH (antidiuretic hormone) secretion.

Anticholinergic

Dry mouth and, rarely, associated sublingual adenitis; blurred vision; disturbances of accommodation; mydriasis; constipation; paralytic ileus; urinary retention; delayed micturition; dilation of the urinary tract.

Allergic

Skin rash, petechiae, urticaria, itching, photosensitization, edema of face and tongue.

Hematologic

Bone marrow depression including agranulocytosis, eosinophilia; purpura; thrombocytopenia. Leukocyte and differential counts should be performed in any patient who develops fever and sore throat during therapy; the drug should be discontinued if there is evidence of pathological neutrophil depression.

Gastrointestinal

Nausea and vomiting, anorexia, epigastric distress, diarrhea, peculiar taste, stomatitis, abdominal cramps, black tongue.

Endocrine

Gynecomastia in males; breast enlargement and galactorrhea in females; increased or decreased libido, impotence; testicular swelling; elevation or depression of blood sugar levels.

Other

Jaundice (simulating obstructive); altered liver function; weight gain or loss; perspiration; flushing; urinary frequency; drowsiness, dizziness, weakness, and fatigue; headache; parotid swelling; alopecia.

Withdrawal Symptoms

Abrupt cessation of treatment after prolonged therapy may produce nausea, headache, and malaise.

Drug Interactions with Surmontil (trimipramine)

Cimetidine

• There is evidence that cimetidine inhibits the elimination of tricyclic antidepressants. Downward adjustment of Surmontil dosage may be required if cimetidine therapy is initiated; upward adjustment if cimetidine therapy is discontinued.

Alcohol

• Patients should be warned about the exaggerated effects of concomitant use of alcoholic beverages.

Catecholamines/Anticholinergics

• Tricyclic antidepressants can potentiate the effects of catecholamines. Atropine-like effects may be more pronounced in patients receiving anticholinergic therapy.
• Care should be exercised when administering tricyclic antidepressants with sympathomimetic amines, local decongestants, local anesthetics containing epinephrine, atropine, or drugs with anticholinergic effects.
• A dose of 2.5 mg/kg/day may need to be exceeded in resistant cases of depression in adults. ECG monitoring should be maintained during dose initiation and stabilization.

Drugs Metabolized by P450 2D6

• The biochemical activity of the drug metabolizing isozyme cytochrome P450 2D6 (debrisoquin hydroxylase) is reduced in a subset of the Caucasian population; estimates of the prevalence of reduced P450 2D6 isozyme activity among other populations are not yet available.
• Poor metabolizers have higher than expected plasma concentrations of tricyclic antidepressants (TCAs) when given usual doses.
• The increase in plasma concentration may be small or quite large depending on the fraction of drug metabolized by P450 2D6 (up to 8 fold increase in plasma AUC of the TCA).
• Certain drugs inhibit the activity of the isozyme and make normal metabolizers resemble poor metabolizers.
• An individual stable on a given dose of TCA may become abruptly toxic when given one of these inhibiting drugs as concomitant therapy.
• The drugs that inhibit cytochrome P450 2D6 include some that are not metabolized by the enzyme (quinidine; cimetidine) and many that are substrates for P450 2D6 (other antidepressants, phenothiazines, and the Type 1C antiarrhythmics propafenone and flecainide).
• All selective serotonin reuptake inhibitors (SSRIs) inhibit P450 2D6, but the extent of inhibition may vary.
• Caution is indicated in the coadministration of TCAs with SSRIs and in switching from one class to the other. Sufficient time must elapse before initiating TCA treatment in a patient being withdrawn from fluoxetine.
• Concomitant use of tricyclic antidepressants with drugs that inhibit cytochrome P450 2D6 may require lower doses than usually prescribed. An increased dose of tricyclic antidepressant may be required when one of these other drugs is withdrawn from co-therapy.
• Desirable to monitor TCA plasma levels whenever a TCA is co-administered with another drug known to be an inhibitor of P450 2D6.

Monoamine Oxidase Inhibitors (MAOIs)

• See prescribing information.

Serotonergic Drugs

• See prescribing information.

Summary

Surmontil (trimipramine) is a tricyclic antidepressant (TCA) used to treat major depression. Common side effects of Surmontil include anti-cholinergic effects and increased sensitivity to sunlight. Safe use of Surmontil during pregnancy or lactation has not been established.