Trimipramine

Trimipramine is a tricyclic antidepressant (TCA) used to treat depression. It has also been used for its sedative, anxiolytic, and mild antipsychotic effects in the treatment of insomnia, anxiety disorders, and psychosis, respectively. Trimipramine is taken by mouth.

Pharmacodynamics

The mechanism of action of trimipramine differs from that of other tricyclic antidepressants. Trimipramine works by decreasing the reuptake of norepinephrine and serotonin (5-HT). Although this response occurs immediately, mood does not lift for about two weeks. It is therefore thought that changes in receptor sensitivity in the cerebral cortex and hippocampus are the reason for the antidepressant effect. The hippocampus is part of the limbic system, a part of the brain involved in emotions.

Pharmacokinetics

Absorption is rapid and plasma protein binding is around 93-96%. Metabolism occurs in the liver. The plasma half-life is around 11-18 hours.

Drug Interactions

Trimipramine should not be given with sympathomimetics such as epinephrine (adrenaline), ephedrine, isoprenaline, noradrenaline, phenylephrine, and phenylpropanolamine.

Barbiturate können die Metabolisierungsrate erhöhen. Trimipramin sollte bei Patienten, die eine Therapie für Hyperthyreose erhalten, mit Vorsicht verabreicht werden.

Side effects

Common adverse effects include:

• Sedation
• Dry mouth
• blurred vision
• Mydriasis
• decreased lacrimation
• Constipation
• hesitation or retention of urine
• reduced GI motility
• tachycardia (high heart rate)
• anticholinergic delirium (especially in the elderly and in Parkinson's disease)
• Weight gain
• Orthostatic hypotension
• Sexual dysfunction including impotence, loss of libido, and other sexual impairments
• Tremors
• Dizziness
• Sweating
• Anxiety
• Insomnia
• restlessness
• Rash

Toxicological data

LD50 (mouse, oral): 250 mg-kg-1