Mark Anderson was told his wife already had an appointment for the following day and he agreed to wait until then.
Mr Anderson did not give evidence at the trial but his phone call to the clinic was confirmed by Dr Thomas McMonagle, one of Ms Anderson's treating psychiatrists at the time.
Dr McMonagle said Mr Anderson was "happy" to wait one more night and that he was told that if there were any problems he could call Tallaght Hospital or gardaí.
Michael O'Higgins SC, defending, opened the case for the defence by saying the issue in the trial was whether Mrs Anderson's behaviour when she stabbed Gareth Kelly to death was driven by her mental issues or by her use of cannabis and whether she was intoxicated with cannabis at the time.
Dr McMonagle was the first defence witness and said Mrs Anderson used cannabis sometimes daily but at times would abstain for long periods. Dr McMonagle said Mrs Anderson had told her doctors she did not associate cannabis use with paranoia and that she found it helpful for her moods.
Mrs Anderson (41) of Brownsbarn Wood, Kingswood, Dublin 22, is charged with murdering 39-year-old Gareth Kelly, who was stabbed five times as he tried to start his car outside her home on the morning of February 25, 2020.
The mother of three has pleaded not guilty by reason of insanity.
Opening the trial last week, counsel for the State Patrick McGrath SC, prosecuting, said there was no dispute Mrs Anderson stabbed Mr Kelly and caused his death. The issue for the jury to decide will be her mental state at the time.
Dr McMonagle was called by the defence following the close of the prosecution case.
He told Mr O'Higgins that Mrs Anderson had been diagnosed with bipolar disorder and that he had been one of her treating doctors since 2018.
He said he was called to Blanchardstown Garda Station to assess whether she was fit for interview following her arrest. He said he found no evidence of intoxication and that he would not have passed her fit for interview if he believed she was intoxicated.
Although he found her fit to be interviewed, he noted there was a "marked contrast" in her behaviour to what he had previously seen during her visits to the clinic.
Normally, he said, she was measured and in control of herself, could make good eye contact, respond appropriately and took pride in her appearance. "What I found in the garda station bore no comparison to that," he said. She "appeared psychotic", he said, and "not in contact with reality".
She was, however, able to respond appropriately when he asked if she knew that killing someone was wrong. She was capable of processing information and he passed her fit for interview but he said there was a "low bar" for that finding.
Mr McGrath SC asked Dr McMonagle if he was aware a toxicology report suggested there was cannabis in Mrs Anderson's system.
The witness said he did not offer any opinion on whether she had cannabis in her system, only whether she was obviously intoxicated. He said a regular user may have a higher tolerance and said "there is an important distinction between intoxication and cannabis being in your system."
Dr McMonagle accepted cannabis use can precipitate a psychotic episode.
The trial continues in front of Ms Justice Karen O'Connor and a jury of seven men and five women.