An Adelaide woman who claimed she was trying to save her husband's life moments before he died has walked free from the Adelaide Magistrates Court after a murder charge against her was dropped.

WARNING: This article contains references to mental health and suicide.

The court previously heard Caroll Hopkinson had killed her husband Simon Hopkinson in an act of self-defence during a struggle, as she tried to stop him from taking his own life.

The 58-year-old attended the Adelaide Magistrates Court on Wednesday, where the charge of murder was formally dropped by a police prosecutor.

Ms Hopkinson is facing no other charges in relation to her husband's death.

Defence lawyer Jeff Powell had previously told the court that the circumstances of the alleged offending were "tragic" and "unusual".

"Ms Hopkinson is in the unfortunate position of having ended the life of her own husband in an act of defence," he told an earlier court hearing.

Mr Powell said Ms Hopkinson woke on the morning of July 7 this year to discover her husband attempting to take his own life and she tried to intervene.

He said she "panicked" and retrieved a knife from the kitchen in an attempt to save him, but that he had reacted "aggressively".

"She understood his reaction, it was to this extent: 'Why are you stopping me from something that I need to [do]' — that is how she interpreted his reaction," he said.

"There occurred a conflict between them, he got the knife from her and he then proceeded to assault her, or attempt to assault her.

"She had cuts to her hands in an attempt to defend herself … there was a struggle, she got the knife back from him and in a desperate moment while he lunged at her again, he was stabbed while she held the knife."

Ms Hopkinson did not comment as she left the Adelaide Magistrates Court.