No, Paxil and Lexapro Should Not Be Taken Together
Taking Paxil (paroxetine) and Lexapro (escitalopram) simultaneously is not recommended and should be avoided. Both medications are SSRIs (selective serotonin reuptake inhibitors) that work through the same mechanism—increasing serotonin levels in the brain—and combining them creates significant risks without therapeutic benefit.
Primary Safety Concern: Serotonin Syndrome
The FDA drug label for Paxil explicitly warns that "the development of a potentially life-threatening serotonin syndrome...have been reported with SNRIs and SSRIs alone, including treatment with PAXIL CR, but particularly with concomitant use of serotonergic drugs" 1. When two SSRIs are combined, the risk of serotonin syndrome increases substantially.
Signs of Serotonin Syndrome to Monitor:
- Mental status changes (agitation, hallucinations, confusion, coma)
- Autonomic instability (rapid heart rate, unstable blood pressure, high fever)
- Neuromuscular problems (hyperreflexia, muscle rigidity, tremor, incoordination)
- Gastrointestinal symptoms (nausea, vomiting, diarrhea)
In severe cases, serotonin syndrome can resemble neuroleptic malignant syndrome with hyperthermia, muscle rigidity, and potentially fatal outcomes 1.
No Evidence of Superior Efficacy
The American College of Physicians guideline states that "existing evidence does not justify the choice of any second-generation antidepressant over another on the basis of greater efficacy and effectiveness" 2. This means:
- All SSRIs have comparable efficacy for treating depression
- Combining two SSRIs does not enhance antidepressant effects
- The risks of combination therapy far outweigh any theoretical benefits
What to Do Instead
If a patient is currently on one SSRI and it's not working adequately:
Optimize the current medication first: Ensure adequate dose and duration (6-8 weeks minimum) 2
Switch, don't combine: Transition from one SSRI to another rather than adding a second one. The guideline recommends modifying treatment if there's inadequate response after 6-8 weeks 2
Consider alternative mechanisms: If switching SSRIs fails, consider antidepressants with different mechanisms (e.g., bupropion, mirtazapine, SNRIs) rather than doubling up on serotonergic agents
Proper washout periods: When switching between SSRIs, allow appropriate time for the first medication to clear, particularly important given paroxetine's potent CYP2D6 inhibition 3
Additional Drug Interaction Concerns
Paroxetine is a potent CYP2D6 inhibitor 3, 4, which can affect the metabolism of numerous other medications. While this primarily impacts drugs metabolized by CYP2D6 (like certain beta-blockers), it adds another layer of complexity when combining multiple psychiatric medications.
Common Pitfall to Avoid
Do not attempt to "augment" one SSRI with another SSRI. True augmentation strategies involve adding medications with different mechanisms of action (such as adding an atypical antipsychotic or lithium to an SSRI), not combining two drugs from the same class.
If a patient presents already taking both medications, contact the prescriber immediately to develop a safe tapering plan, as abrupt discontinuation of either medication can cause withdrawal symptoms 1.