Laboratory Monitoring for Sertraline
Routine laboratory monitoring is not required for patients taking sertraline, as SSRIs do not necessitate specific laboratory tests during treatment. 1
Baseline Assessment
Before initiating sertraline therapy, the following clinical parameters should be documented:
- Height, weight, pulse, and blood pressure should be measured at baseline 1
- No specific laboratory tests are recommended for SSRI initiation, including sertraline 1
- Pregnancy testing should be performed in females of childbearing age, as patients should notify their physician if they become pregnant or intend to become pregnant during therapy 2
The American Academy of Child and Adolescent Psychiatry guidelines explicitly state that for SNRIs (which have a similar monitoring profile to SSRIs), medical monitoring should include only height, weight, pulse, and blood pressure, with no specific laboratory tests recommended 1. This same principle applies to sertraline and other SSRIs 1.
Ongoing Monitoring During Treatment
Clinical monitoring focuses on symptoms and vital signs rather than laboratory values:
- Height, weight, pulse, and blood pressure should be monitored at follow-up visits 1
- Suicidality assessment is critical, especially in the first months of treatment and following dosage adjustments, given the FDA boxed warning for suicidal thinking and behavior through age 24 years 1
- Bleeding risk evaluation should be performed clinically, particularly in patients taking NSAIDs, aspirin, warfarin, or other anticoagulants, as SSRIs increase bleeding risk 2
Special Circumstances Requiring Laboratory Testing
While routine labs are not needed, specific clinical situations may warrant targeted testing:
- Prothrombin time/INR monitoring should be carefully performed when sertraline therapy is initiated or stopped in patients taking warfarin, as sertraline can increase prothrombin time by approximately 8% 2
- Sodium levels should be checked if clinical signs of hyponatremia develop (confusion, headache, weakness), though this is not routine monitoring 1
- Liver function tests are not routinely required but should be obtained if symptoms suggesting hepatotoxicity develop (jaundice, abdominal pain, dark urine), as severe hepatotoxicity is extremely rare but has been reported 3
Important Clinical Caveats
False-positive urine drug screens for benzodiazepines have been reported in patients taking sertraline due to lack of specificity of immunoassay screening tests 2. This can persist for several days after discontinuation. Confirmatory testing with gas chromatography/mass spectrometry will distinguish sertraline from benzodiazepines 2.
Therapeutic drug monitoring of sertraline plasma levels is not clinically useful, as only sparse data support correlations between sertraline plasma concentrations and therapeutic or adverse effects 4. Steady-state plasma concentrations vary widely (up to 15-fold) even at standard doses of 50-150 mg/day, but this variability does not justify routine monitoring 4.
No dosage adjustments or additional monitoring are required based solely on age in elderly patients or in patients with renal impairment 5, 6.