Brief Answer:
Serotonin syndrome is likely with this combination- details below

Detailed Answer:
Hello and welcome to "Ask A Doctor" service,

I carefully read your query and understand your concern with drug interactions if you take more than one drug at a time.

Lexapro (citalopram) and phentermine if taken together may cause what we call serotonin syndrome. This is a condition that may seriously impact patients by causing increased body temperature, high blood pressure and heart problems, irritability and confusion, sweating, diarrhea, muscle rigidity and twitching and if severe may cause seizures, very high fever, irregular heartbeat and even coma.

I would recommend you to talk with your doctor related to this possible serious interaction and discuss if other alternative drugs can be used to avoid it and also discuss the need for close follow-ups to monitor potential side effects.

I hope this answers your query.
I remain at your disposal in case further medical assistance is needed.

Regards,
Dr. Antoneta Zotaj,
General and Family Physician

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