Desipramine Level

Antidepressants are multicyclic compounds that increase the concentration of monoamines in the synapse by inhibiting the metabolism of neurotransmitters or preventing their uptake. ^[1] Because of the high risk of suicidality in depressed patients, the safety of antidepressants after an overdose is of critical importance. Desipramine is a tricyclic antidepressant (TCA). Being the most potent sodium channel blocker among its group, it causes severe cardiotoxicity (eg, wide QRS complex, hypotension) without producing significant antimuscarinic symptoms.

The reference range for desipramine is as follows:

• Normal range: 100-300 ng/mL

• Potentially toxic level: >500 ng/mL ^[1]

Desipramine levels are increased in overdose.

See the list below:

• Specimen: Blood

• Container: Serum separator tube (SST)

All samples must be sent in a sealed, leak-proof container marked with a biohazard sticker to comply with Occupational Safety and Health Administration (OSHA) safety standards.

Antidepressants are multicyclic compounds that increase the concentration of monoamines in the synapse by inhibiting the metabolism of neurotransmitters or preventing their uptake. ^[1] Because of the high risk of suicidality in depressed patients, the safety of antidepressants after an overdose is of critical importance. Desipramine is a tricyclic antidepressant (TCA). Being the most potent sodium channel blocker among its group, it causes severe cardiotoxicity (eg, wide QRS complex, hypotension) without producing significant antimuscarinic symptoms.

It is associated with a higher fatality rate than the other cyclic antidepressants based on the number of drug exposures. ^{[2, 3]}

Desipramine falls in the broad group of tricyclic antidepressants (TCA). Currently, it is used primarily in depression that is resistant to more commonly used antidepressants such as the selective serotonin reuptake inhibitors (SSRIs) or serotonin and norepinephrine reuptake inhibitors (SNRIs). Loss of popularity of TCAs is due to relatively poorer tolerability in comparison to newer agents, difficulty of use, and lethality in overdose scenarios. ^[4]

Additionally, TCAs has been used in the therapy of pain, enuresis, and insomnia. ^[5] Desipramine has been found useful in the therapy of irritable bowel syndrome (IBS). Empiric evidence for efficacy of its use in the treatment of IBS exists. Desipramine causes less sedation and constipation in comparison to other members of the group. ^[6]

A literature review by Pérez-López et al indicated that in women with vestibulodynia, treatment with oral desipramine, with or without topical lidocaine, can lead to significant improvement in the Index of Sexual Satisfaction score, as assessed by the investigators through network meta-analyses. ^[7]

Because of the variable cross-reactivity with other TCAs and their metabolites, manufacturer’s package insert should be consulted. ^[1]

See the list below:

• Drug overdose

TCA overdose may cause neurotoxic (particularly seizures) and anticholinergic (eg, dry mouth, constipation, urinary retention) effects. Additionally, TCA overdose can result in life-threatening cardiotoxicity requiring prompt therapy with its antidotes. Although the benefit of gastrointestinal decontamination is controversial, ^[8] activated charcoal should be used in TCA overdose, particularly when sustained release formulation is used. If a patient is intubated, the airway should be secured with a cuffed endotracheal tube before administration of activated charcoal.

As many patients with poisoning are unable or unwilling to provide a reliable history, laboratory evaluation is vitally important. Blood glucose should be checked in all patients with mental status changes or those who have active seizures. A comprehensive metabolic panel and ECG may provide crucial information regarding end-organ damage and insight into potential deterioration in a patient’s condition. A quantitative test for common co-ingestants, such as acetaminophen or aspirin, may be necessary, whereas quantitative testing of specific antidepressants is not recommended. ^[9]

Immunoassay screening of serum/plasma/urine for tricyclic antidepressants does not detect newer antidepressants (eg, SSRIs). ^[1]