Sertraline and Nortriptyline: Interaction Details
AI-assisted, pharmacist-reviewed · AI content regenerated Jul 11, 2026 · Source data updated Jul 2, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Nortriptyline
No brand names on recordSertraline
No brand names on record
How we grade severity & evidence
Severity levels
- Contraindicated: These should generally not be used together.
- Major: Potentially serious — often needs a change or close monitoring.
- Moderate: Can be significant — usually manageable with monitoring.
- Minor: Usually limited clinical impact.
Evidence grades
- Established: Well documented — supported by controlled studies or strong clinical data.
- Probable: Good supporting evidence, though not definitively proven.
- Suspected: Some evidence suggests this interaction, but it is not well established.
- Possible: Limited or conflicting evidence; the interaction may occur.
- Theoretical: Predicted from the drugs' pharmacology; not yet confirmed in people.
Ratings come from the documented interaction literature and are reviewed by a pharmacist. They describe the documented risk of the combination, not what will necessarily happen to you — your dose, timing, and health picture all matter.
You're taking two medicines that both affect a brain chemical called serotonin. Sertraline also slows down a liver enzyme (CYP2D6) that normally clears nortriptyline out of your body. That means nortriptyline can build up a little higher than expected.
Two things can happen. First, more nortriptyline in your system can mean more side effects like drowsiness, dry mouth, or a fast heartbeat. Second, because both drugs raise serotonin, together they slightly raise the risk of a reaction called serotonin syndrome, which can cause agitation, shakiness or twitching, fever, sweating, and a racing heart. The good news: your care team can manage this by adjusting your dose and keeping an eye on you. Keep taking both as prescribed and call your doctor if you feel unwell.
Effect: Sertraline weakly inhibits CYP2D6, reducing nortriptyline metabolism and increasing TCA serum levels; additive serotonergic activity raises serotonin syndrome risk.
Direction: Increased nortriptyline exposure (nortriptyline is an active TCA, not a prodrug). Reported PK increases are modest versus fluoxetine/desipramine.
Onset: Delayed. Evidence: Probable. Severity: Major.
- Monitor for serotonin syndrome (hypertension, hyperthermia, myoclonus, mental status changes), especially at initiation and dose increases.
- Consider nortriptyline level monitoring; TCA dose may need reduction and individualization.
- If sertraline is discontinued, the nortriptyline dose may need to be increased.
- If serotonin syndrome suspected, discontinue offending agent(s) and give supportive care.
What happens
Increased nortriptyline exposure and an increased risk of serotonin syndrome (hypertension, hyperthermia, myoclonus, mental status changes)
Interaction Deep Dive
Taking sertraline together with serotonergic CYP2D6 substrates such as nortriptyline can raise nortriptyline exposure and potentially trigger serotonin syndrome. It may be necessary to lower the dose of the CYP2D6 substrate. On the other hand, if sertraline is stopped, the CYP2D6 substrate dose may need to be raised. As a CYP2D6 inhibitor, sertraline has been linked to serotonin syndrome even when used alone. Combining it with additional serotonergic agents such as nortriptyline heightens the likelihood of this event. When the combination cannot be avoided, watch for signs of serotonin syndrome, particularly at the start of therapy and when doses are raised. Should serotonin syndrome be suspected, sertraline and/or nortriptyline should be stopped without delay and supportive care given1. Some limited data indicate that sertraline could inhibit the metabolism of tricyclic antidepressants (TCAs), leading to elevated TCA serum concentrations. Because sertraline is a weak inhibitor of CYP2D6 enzyme activity, it may raise the plasma levels of concurrently administered drugs cleared by this route, tricyclic antidepressants among them 23. The clinical significance of this interaction may be minimal or absent; the rise in TCA serum levels seen with sertraline coadministration was modest relative to the increases observed when FLUoxetine (another selective serotonin reuptake inhibitor) was given with desipramine 4.
Why it happens (mechanism)
Inhibition of CYP2D6-mediated nortriptyline metabolism; additive serotonergic effects
How to manage this interaction
Keep taking both medicines as prescribed unless your prescriber tells you otherwise. This combination can be used safely with a little extra care.
- Your care team may reduce your nortriptyline dose and individualize it, since sertraline can raise nortriptyline levels.
- They may monitor you more closely, especially when starting or increasing a dose, and may check nortriptyline blood levels.
- If sertraline is later stopped, your nortriptyline dose may need to be raised again.
- Contact your pharmacist or doctor right away if you notice agitation, confusion, muscle twitching, fever, sweating, shivering, or a fast heartbeat.
Management is individual — confirm any change with your pharmacist or prescriber.
Literature reports
2 reports — tap to read
a) The pharmacokinetics of desipramine were investigated in 18 healthy male volunteers. Participants took desipramine alone (50 mg daily) for 7 days, and then desipramine together with sertraline (50 mg daily) for 21 days. With the addition of sertraline to desipramine, the desipramine Cmax rose by 34% and the AUC rose by 26%. One week after sertraline was stopped, trough desipramine levels were near baseline. These alterations in desipramine concentrations were modest, and the interaction may not be clinically significant 2.
b) A retrospective analysis of fourteen elderly depressed patients was conducted to assess how sertraline therapy affected their nortriptyline levels. Sertraline was started at 25 mg or 50 mg daily and titrated up to 150 mg daily. On the whole, sertraline produced a median rise of only 2% in nortriptyline levels. Nonetheless, two patients had changes of 51% and 117%, which might carry clinical implications. Among patients receiving sertraline at doses of 100 mg or 150 mg daily, the nortriptyline level rose by 40%, with a range of -12% to 239%. Given the wide variability observed in the change of nortriptyline levels, careful monitoring of nortriptyline concentrations should be carried out in patients treated with sertraline and nortriptyline 5.
Common questions
Can I take Sertraline and Nortriptyline together?
Sertraline can raise nortriptyline levels and adds to serotonin activity, so watch for serotonin syndrome symptoms and let your care team adjust the dose and monitor you. Keep taking both as prescribed unless told otherwise. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Sertraline and Nortriptyline interaction?
It is rated major. Potentially serious — often needs a change or close monitoring.
How quickly could this interaction happen?
The documented onset is "delayed". Effects tend to build up gradually over days to weeks.
How is the Sertraline and Nortriptyline interaction managed?
Keep taking both medicines as prescribed unless your prescriber tells you otherwise. This combination can be used safely with a little extra care. Your care team may reduce your nortriptyline dose and individualize it, since sertraline can raise nortriptyline levels. They may monitor you more closely, especially when starting or increasing a dose, and may check nortriptyline blood levels. If sertr… Management is individual — always follow your own care team's guidance.
How strong is the evidence for this interaction?
The evidence is graded "probable". Good supporting evidence, though not definitively proven.
From our Q&A
Real reader questions about these medications, each personally answered by our pharmacist:
Questions for your pharmacist
- Does my dose of Sertraline or Nortriptyline need adjusting while I take them together?
- What symptoms should prompt me to call you or my prescriber right away?
- Does the timing of my doses matter for this combination?
- Is there a safer alternative to one of these medications for me?
References (5)
- Product Information: ZOLOFT oral tablets, oral solution, sertraline hydrochloride oral tablets, oral solution. Viatris Specialty LLC (per FDA), Morgantown, WV, 2023. DailyMed
- Preskorn SH, Alderman J, Chung M, et al: Pharmacokinetics of desipramine coadministered with sertraline or fluoxetine. J Clin Psychopharmacol 1994; 14:90-98. DOI
- Lydiard RB, Anton RF, & Cunningham T: Interactions between sertraline and tricyclic antidepressants. Am J Psychiatry 1993; 150:1125-1126. PubMed
- von Moltke LL, Greenblatt DJ, Cotreau-Bibbo MM, et al: Inhibition of desipramine hydroxylation in vitro by serotonin- reuptake-inhibitor antidepressants, and by quinidine and ketoconazole; a model system to predict drug interactions in vivo. J Pharmacol Exp Ther 1994; 268:1278-1283. DOI
- Solai LK, Mulsant BH, Pollock BG, et al: Effect of sertraline on plasma nortriptyline levels in depressed elderly. J Clin Psychiatry 1997; 58:440-443. PubMed
Keep reading about Nortriptyline
Keep reading about Sertraline
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