A man accused of murdering his wife using knives, hammers and a screwdriver told a jury he had "darkness" in his mind after taking strong medication with black tea.
Andriejus Kostiajevas, 47, is alleged to have killed his wife Ligita Kostiajeviene, 42, in Cromwell Road, Peterborough, on 2 July.
Mr Kostiajevas said he was unable to remember many events of that day.
He denies murder, attempted murder and wounding with intent.
Stuart Trimmer QC, prosecuting, previously told Cambridge Crown Court Mr Kostiajevas attacked his wife in their bedroom before resuming later when she "retreated" to the corner of another room.
She was pronounced dead at the scene and a post-mortem examination found she had a broken skull and multiple stab wounds, the jury heard.
Mr Kostiajevas denied being in what Mr Trimmer called "an enormous or supreme rage" that morning.
The jury has previously been told the former postal worker had a history of epilepsy and seizures.
Mr Kostiajevas said he took "very strong medication every day" and that morning could remember taking tablets with "very black tea", and "then everything went dark".
'Going to stab'
When asked whether he accepted deliberately taking knives up to their bedroom where his wife was, Mr Kostiajevas said: "Whether deliberate or not I must have taken them somehow - something must have switched somewhere."
Mr Trimmer alleged a witness heard the defendant saying during the attack: "I'm never going to calm down, I'm going to stab." Mr Kostiajevas said he could not remember saying that.
He denies murder, the attempted murder of a child in the same attack, wounding with intent, unlawful wounding and assaulting an emergency worker.
Rosina Cottage QC, defending, has previously told the court it was not "his actions that are in dispute but what was in his mind at the time".
The trial continues.