Amanda Young was  found not guilty at Bristol Crown Court last June of the manslaughter by gross negligence of Joshua Gafney, 22.
Mr Gafney died after being given 14 times his prescribed dose of anti-psychotic drug by Ms Young in 2012.
The Nursing and Midwifery Council found Ms Young's fitness to practise was "impaired by reason of her misconduct".
"A striking-off order is the proportionate and appropriate sanction," the council panel said.
The panel said Miss Young's misconduct represented a "significant and serious departure" from the standards expected of her as a registered nurse.
It said there had been a series of "significant failures in basic nursing care" and Mr Gafney's death was "entirely avoidable".
"There were a number of obvious opportunities, had Miss Young discharged her nursing responsibilities to the expected standards, for her to have prevented his death," the panel said.
"Her overarching duty was to safeguard a vulnerable patient in her care. She failed wholly to discharge that duty."
The Nursing and Midwifery Council is the nursing and midwifery regulator for England, Wales, Scotland, Northern Ireland and the Islands.
During her trial, Ms Young said she had not seen details of the drug's strength written on the bottle's label.
A nurse who gave a patient a lethal overdose of a prescription drug has been struck off the nursing register.