Wendy-Ann Russell was found in her bed by her son Jonathan at the family home in Coleraine on September 30 last year.

The 50-year-old mother-of-three had been prescribed the drug to treat chronic back pain.
The inquest at Coleraine Courthouse was told Mrs Russell was taking three other drugs for depression.

A few weeks before her death one of her doctors increased her morphine dosage to 140mg twice a day - above normal therapeutic levels.
Her husband, the former police commander in Coleraine, told the inquest his wife had undergone several operations to fix her back.
However, her last surgical procedure in 2007 failed to ease her suffering and she was prescribed pain medication to give her a "better quality of life".

Mr Russell said that after the birth of their three children his wife had severe post-natal depression and was on several drugs to help control the symptoms.
Coroner Brian Sherrard asked if he had any concerns about his wife's mental health in the weeks prior to her death.
Mr Russell, a recipient of the Queen's Medal for policing, replied that she was happier than she had been in recent years and looking forward to taking a family holiday now he had retired.

The couple's son Jonathan, a medical student, said that he thought she was in "good spirits" the night before she died.
He said that his mother had been excited about his return from Guinea, where he had been working voluntarily.
A post-mortem examination revealed the former legal researcher died from morphine toxicity combined with amitriptyline, carbamazapine and diazepam.

However Dr Andrew Cooper, a consultant anaesthetist in pain management at Causeway Hospital, who was treating Mrs Russell, told the inquest that it was not uncommon for people with chronic back pain to be given such high doses of morphine.
The Coroner said he believed the mother-of-three's death was "purely accidental".