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Test Code IMIPQ Imipramine and Desipramine, Serum

Important Note

Mayo test code IMIPR

Useful For

Monitoring serum concentration during therapy


Evaluating potential toxicity


The test may also be useful to evaluate patient compliance

Method Name

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

Reporting Name

Imipramine and Desipramine, S

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 Special Container
Serum Red Refrigerated (preferred) 28 days
  Frozen  28 days
  Ambient  7 days

Reject Due To

Gross hemolysis Reject
Gross lipemia Reject
Gross icterus Reject

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.



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 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.

Reference Values


Total therapeutic concentration: 175-300 ng/mL



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, Wednesday, Friday; Varies

Analytic Time

2 days

Performing Laboratory

Mayo Clinic Laboratories in Rochester

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


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

NY State Approved



If not ordering electronically, complete, print, and send 1 of the following forms with the specimen:

-Cardiovascular Test Request Form (T724)

-Therapeutics Test Request (T831)

Northwell Health Laboratories Additional Information:

Computer Interface Code

    PDM #  5915021