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Epic Code LAB1230481 Clomipramine, Serum

Important Note

May 8, 2018 - This test replaces LAB752

Additional Codes

Mayo Code: CLOM

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Useful For

Determining whether a poor therapeutic response is attributable to noncompliance


Monitoring serum concentration of clomipramine and norclomipramine to assist in optimizing the administered dose

Specimen Type

Serum Red

Specimen Required

Collection Container/Tube: Red top (Serum gel/SST are not acceptable)

Submission Container/Tube: Plastic vial

Specimen Volume: 1 mL

Collection Instructions:

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

2. Centrifuge and aliquot serum into plastic vial. Serum must be separated from cells within 2 hours of collection.

Laboratory Test Directory Note:

COLLECTION NOTE: Volumes listed are in serum or plasma, draw approximately 2 1/2 times the requested volume in whole blood.

Specimen Minimum Volume



If not ordering electronically, complete, print, and send a Therapeutics Test Request (T831) with the specimen.

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 OK
Gross lipemia OK
Gross icterus OK


This test cannot be performed on whole blood. Serum must be separated from cells within 2 hours of collection; if serum is not removed within this time, tricyclic antidepressant levels may be falsely elevated due to drug release from red blood cells.


Specimens that are obtained from gel tubes are not acceptable because the drug can absorb on the gel and lead to falsely decreased concentrations.

Clinical Information

Clomipramine (chlorimipramine, Anafranil) is a tricyclic antidepressant drug used primarily to treat obsessive-compulsive disorder. Clomipramine is also used to treat panic disorder and treatment-resistant depression.


Clomipramine preferentially blocks synaptic reuptake of serotonin; its pharmacologically active metabolite, norclomipramine (desmethylchlorimipramine) preferentially blocks synaptic reuptake of norepinephrine.


Clomipramine undergoes significant first-pass hepatic metabolism (up to 50%), which probably explains the high degree of interindividual variability observed between administered dose and steady-state serum concentrations of the drug and its metabolite. The serum ratio of clomipramine to norclomipramine is typically 1:2-2.5. The elimination half-lives of clomipramine and norclomipramine are 19 to 37 hours and 54 to 77 hours, respectively. When a patient is started on clomipramine or following an alteration in the dose, 1 to 2 weeks are required to achieve a steady-state condition.


Anticholinergic side effects (ie, dry mouth, excessive sweating, blurred vision, urinary retention, constipation) frequently accompany treatment. Other side effects may include tremor, nausea, orthostatic hypotension, dizziness, sexual dysfunction, and sleep disturbances. Signs and symptoms following overdose are similar to other tricyclic antidepressant drugs: cardiac toxicity (eg, tachycardia, arrhythmia, impaired conduction, congestive heart failure) is the major concern.

Method Name

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

Report Available

3 to 5 days

Reporting Name

Clomipramine, S

Reference Values


Therapeutic concentration: 230-450 ng/mL


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


Studies investigating the relationship between serum concentrations of clomipramine and norclomipramine and therapeutic response have yielded conflicting results. However, the probability of therapeutic failure seems to increase if the sum of the clomipramine and norclomipramine serum concentrations is <230 ng/mL. Summed serum concentrations of clomipramine and norclomipramine that exceed 450 ng/mL seem to result in no additional enhancement in therapeutic response and may predispose the patient to greater risk of adverse side effects. A toxic range has not been well established at this time.

Method Description

The tricyclic antidepressants are extracted from serum using a solvent crash to precipitate proteins. The supernatant is remove and analysis is by liquid chromatography - tandem mass spectrometry.(Unpublished Mayo method)

Day(s) Performed

Tuesday, Thursday, Sunday

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 SHL: Antidepressant poisoning. Clin Med (Lond). 2003 Mar-Apr;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 Sep;44(6):195-235

4. Burtis CA, Ashwood ER, Bruns DE, eds. Tietz Textbook of Clinical Chemistry and Molecular Diagnostics. 5th ed. Elsevier; 2012

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 US Food and Drug Administration.

CPT Code Information


G0480 (if appropriate)

LOINC Code Information

Test ID Test Order Name Order LOINC Value
CLOM Clomipramine, S 43127-0


Result ID Test Result Name Result LOINC Value
80902 Clomipramine 3491-8
7983 Norclomipramine 3536-0
7984 Clomipramine + Norclomipramine 3493-4