From the FDA Drug Label
The extent to which SSRI-TCA interactions may pose clinical problems will depend on the degree of inhibition and the pharmacokinetics of the SSRI involved Nevertheless, caution is indicated in the co-administration of TCAs with sertraline, because sertraline may inhibit TCA metabolism. Plasma TCA concentrations may need to be monitored, and the dose of TCA may need to be reduced, if a TCA is co-administered with sertraline
Sertraline can be used in combination with a tricyclic antidepressant (TCA), but caution is advised due to the potential for sertraline to inhibit TCA metabolism.
- Plasma TCA concentrations may need to be monitored.
- The dose of TCA may need to be reduced. 1
From the Research
The most suitable antidepressant to use in combination with a tricyclic antidepressant (TCA) is citalopram, due to its limited effect on TCA serum levels, as suggested by a study published in 1995 2. When considering the combination of antidepressants with TCAs, it's crucial to prioritize medications that have a lower risk of adverse interactions.
- The combination approach typically involves starting with lower doses of both medications and gradually titrating upward while monitoring for side effects.
- For example, one might begin with 25mg of amitriptyline at bedtime alongside 10mg of citalopram in the morning, adjusting as needed.
- Careful monitoring is essential due to potential drug interactions, such as the inhibition of TCA metabolism through the cytochrome P450 system, potentially increasing TCA blood levels and risk of toxicity.
- This combination may also increase the risk of serotonin syndrome, characterized by agitation, confusion, rapid heart rate, and elevated blood pressure.
- Regular blood level monitoring of the TCA is recommended, along with ECG monitoring due to the potential for QT prolongation and other cardiac effects. A more recent study from 2013 3 compared the efficacy and acceptability of selective serotonin reuptake inhibitors (SSRIs) and tricyclic antidepressants (TCAs) in the treatment of chronic depression, finding that both are efficacious but SSRIs show better acceptability in terms of dropout rates.
- However, the specific interaction between TCAs and SSRIs, such as citalopram, was not the primary focus of this study.
- The choice of citalopram is based on its pharmacokinetic profile, which suggests a lower risk of significant drug interactions with TCAs compared to other SSRIs like fluoxetine, sertraline, or paroxetine, as indicated by the 1995 study 2.