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Test Code 5760 Imipramine and Desipramine, Serum

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Specimen Type

Serum Red


Specimen Required


Container/Tube: Red top

Specimen Volume: 1 mL

Collection Instructions:

1. Draw specimen immediately before next scheduled dose (minimum 12 hours after last dose).

2. Serum must be separated from cells within 2 hours of draw.


Specimen Minimum Volume

0.25 mL

Specimen Stability Information

Specimen Type Temperature Time
Serum Red Refrigerated (preferred) 28 days
  Frozen  28 days
  Ambient  7 days

Reference Values

IMIPRAMINE AND DESIPRAMINE

Total therapeutic concentration: 175-300 ng/mL

 

DESIPRAMINE ONLY

Therapeutic concentration: 100-300 ng/mL

Note: Therapeutic ranges are for specimens drawn at trough (ie, immediately before next scheduled dose). Levels may be elevated in non-trough specimens.

Day(s) and Time(s) Performed

Monday through Friday; Varies

Test Classification

This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the U.S. Food and Drug Administration.

CPT Code Information

80335

G0480 (if appropriate)

LOINC Code Information

Test ID Test Order Name Order LOINC Value
IMIPR Imipramine and Desipramine, S 43123-9

 

Result ID Test Result Name Result LOINC Value
63508 Imipramine 3690-5
37121 Desipramine 3531-1
37122 Imipramine and Desipramine 9627-1

Clinical Information

Imipramine and its metabolite desipramine are tricyclic antidepressants used to treat endogenous depression requiring 1 to 3 weeks of treatment before therapeutic effectiveness becomes apparent. Desipramine is used for treatment of endogenous depression when the patient needs a drug with significant stimulatory side effects. These drugs have also been employed in the treatment of enuresis (involuntary urination) in childhood and severe obsessive-compulsive neurosis.

 

Imipramine:

The optimal dosage of imipramine yields trough (just before the next dose) blood levels of imipramine and desipramine combined from 175 to 300 ng/mL. If desipramine is given, no imipramine should be detected and the therapeutic concentration for desipramine alone is 100 to 300 ng/mL.

 

Toxicity associated with imipramine is characterized by QRS widening leading to ventricular tachycardia and asystole. In some patients, toxicity may manifest at lower concentrations, or at therapeutic concentrations in the early state of therapy. Cardiac toxicity (first-degree heart block) is usually associated with blood concentrations in excess of 400 ng/mL.

 

Desipramine:

Desipramine is the antidepressant of choice in patients where maximal stimulation is indicated.

 

The therapeutic concentration of desipramine is 100 to 300 ng/mL. About 1 to 3 weeks of treatment are required before therapeutic effectiveness becomes apparent.

 

The most frequent side effects are those attributable to anticholinergic effects; dry mouth, constipation, dizziness, tachycardia, palpitations, blurred vision, and urinary retention. These occur at blood concentrations in excess of 400 ng/mL, although they may occur at therapeutic concentrations in the early stage of therapy. Cardiac toxicity (first-degree heart block) is usually associated with blood concentrations in excess of 400 ng/mL.

Interpretation

Most individuals display optimal response to imipramine when combined serum levels of imipramine and desipramine are between 175 and 300 ng/mL. Risk of toxicity is increased with levels above 400ng/mL.

 

Most individuals display optimal response to desipramine with serum levels of 100 to 300 ng/mL. Risk of toxicity is increased with desipramine levels above 400 ng/mL.

 

Some individuals may respond well outside of these ranges, or may display toxicity within the therapeutic range, thus, interpretation should include clinical evaluation.

 

Therapeutic ranges are based on specimen drawn at trough (ie, immediately before the next dose).

Clinical Reference

1. Wille SM, Cooreman SG, Neels HM, Lambert WE: Relevant issues in the monitoring and the toxicology of antidepressants. Crit Rev Clin Lab Sci 2008;45(1):25-89

2. Thanacoody HK, Thomas SH: Antidepressant poisoning. Clin Med 2003;3(2):114-118

3. Hiemke C, Baumann P, Bergemann N, et al: AGNP Consensus Guidelines for Therapeutic Drug Monitoring in Psychiatry: Update 2011. Pharmacopsychiatry 2011;44(6):195-235

4. Tietz Textbook of Clinical Chemistry and Molecular Diagnostics. Edited by CA Burtis, ER Ashwood, DE Bruns. 2012. Fifth edition. Elsevier

Method Name

Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS)

Forms

If not ordering electronically, complete, print, and send a Cardiovascular Test Request Form (T724) with the specimen.