Hello,
I understand your concern.
Tramadol is an analgesic, that is pain killer.
But like other drugs it too has side effects.
Tramadol is an opioid, narcotics hence it has proved to be addictive.
Noted side effects are,
Nausea
Dizziness
Vomiting
Diarrhea, etc.
Next Steps
Ask your brother to consult a physician for his pain management, instead of taking medications on his own.
Health Tips
For medications you may consult online.
Stay healthy.