SST tubes are not acceptable as the separating gel interferes with the assay.
The quoted therapeutic ranges are for trough concentrations, and therefore the specimens should be collected within 1 hour before administering the next dose of the drug.
The concentrations reported as from 18 January 2007 are imipramine immunoreactive equivalents, being derived from an immunoassay aligned with imipramine.
This is a screening assay which detects the commonly used tricyclic antidepressants and is not specific for any particular drug. Different drugs have different cross-reactivities in the assay and the therapeutic intervals shown below have been adjusted accordingly. The value reported is only an estimation of the total amount of tricyclic drug and metabolites, and is not an accurate quantitation.
|
Drug |
Therapeutic Interval (nmol/L; imipramine equivalents) |
|
Imipramine |
570-1580 |
|
Desiprimine |
420-1000 |
|
Nortriptyline |
240-500 |
|
Amitryptyline |
480-1120 |
|
Clomipramine and norclomipramine |
380-910 |
|
Doxepin and nordoxepin |
200-480 |
|
Trimipramine |
240-610 |
|
Dothepin |
130-480 |
Adjustments to therapy should be based on the clinical response rather than on serum concentrations alone. Some patients can be adequately maintained at concentrations outside the therapeutic range
Agranulocytosis has been associated with tricyclic antidepressants; the full blood count should be monitored during treatment, especially if the patient develops a fever, sore throat, or viral infection.
Emails to chemicalpathologist@adhb.govt.nz will receive priority attention from the on-call chemical pathologist.
If the query concerns a specific patient please include the NHI number in your email.
If email is not a suitable option, please contact the on-call chemical pathologist via Lablink (Auckland City Hospital ext. 22000 or 09-3078995).
Individual chemical pathologists may be contacted but will not be available at all times.
After-hours : contact Lablink (Auckland City Hospital ext. 22000 or 09-3078995) or hospital operator for on duty staff after hours.
Dr Samarina Musaad (Clinical Lead) : SamarinaM@adhb.govt.nz ext. 22402
Dr Cam Kyle: CampbellK@adhb.govt.nz ext 22052
Dr Weldon Chiu: WeldonC@adhb.govt.nz ext. 23427
Dr Campbell Heron: CHeron@adhb.govt.nz ext. 23427
Dr Sakunthala Jayasinghe: Sakunthala@adhb.govt.nz ext. 23427