Imipramine

Casandra

Casandra Test Code LC49599Version 1 (DRAFT)

Performing Lab

Lab LabcorpLab Test ID 007468CPT Code 80299

Also known as: Tofranil-PM®, Tofranil®

Clinical Use

Order Test

Use

Imipramine is the most thoroughly studied tricyclic antidepressant for the treatment of agoraphobia and panic disorder. Several small, placebo-controlled studies and open trials have confirmed the panic-blocking effects of this drug; however, many of these studies also employed behavioral therapy, thus obscuring the relative contribution of imipramine. A recent placebo-controlled, dose-response study confirmed that imipramine alone has significant antipanic and antiphobic effects. The best response was obtained at a dosage of 150−200 mg/day (mean, 185 mg/day). Most other studies also emphasize titrating the dosage to establish plasma concentrations within the range used for the treatment of depression; however, some patients may respond to doses <100 mg/day. Imipramine also has been given with high-potency benzodiazepines for panic disorder.

Special Instructions

Therapeutic drug monitoring is recommended to assess the influence of co-medications, diet, smoking habits, and organ function on drug levels. Imipramine's metabolite, desipramine, is also pharmacologically active. Avoid use in pregnant or lactating women. Use caution in geriatric patients due to risks such as postural hypotension.

Limitations

This test is developed by Labcorp for clinical purposes but is not FDA-cleared or approved. Imipramine and other tricyclic antidepressants have significant drug interactions. They engage hepatic enzymes like CYP3A4, CYP1A2, and CYP2C9, potentially reducing antidepressant effectiveness. Gel-barrier tubes should not be used due to possible drug absorption impacting results. Regular monitoring is advised to mitigate interactions with other medications and substances.

Test Details