Hello and Welcome to ‘Ask A Doctor’ service. I have reviewed your query and here is my advice.
Suggestive of
serotonin syndrome. I've gone through your query and I appreciate your concerns for your beloved mother. Taking Oxycodone together with Citalopram hydrobromide can increase the risk of a serious condition called the serotonin syndrome which is characterized by confusion,
hallucination, seizure, increased blood pressure and heart rate, fever,
excessive sweating, shivering or shaking,
blurred vision, muscle stiffness, tremor, motor
incoordination, vomiting, and diarrhea. In its severe form it may result in coma and even death. This is not a normal side effect so she should be taken to ER immediately for further evaluation and treatment. While taking Citalopram or Oxycodone together with Lyrica may increase side effects such as dizziness, drowsiness, confusion, difficulty concentrating, impaired thinking, judgment, and motor coordination. She may need dose adjustment or alternate effective drugs to minimize the risk of the above side effects.
Hope I have answered your query. Let me know if I can assist you further.