It is not possible to put restrictions on the drug which a junior doctor took without permission and used to end his life, an internal hospital review found.
Dr Adam Osborne, who was originally from Belfast, visited the A&E department of Tallaght Hospital the day before he died by injecting himself with a lethal cocktail of drugs.
Dr Osborne (29), who suffered from depression and had made a previous attempt on his life, wrote farewell notes saying he took the potassium from the Co Dublin hospital.
His inquest heard that both his girlfriend and a college friend said Dr Osborne had been feeling unwell in the days leading up to his death.
His girlfriend, Dr Mairead Byrne, said he stayed in her apartment in Dublin on July 13 and July 14 last year. He said he felt terrible, and was worried about a lot of things, including his job and their future.
Dublin Coroner's Court heard Dr Osborne checked himself into the Tara Towers Hotel, Merrion Road, in Dublin, on Sunday, July 15, for one night.
When he failed to check out the following morning, a member of staff went to check on him, but he was not moving and the emergency services were called.
Garda Susan Tobin said that when she went into the bedroom, Dr Osborne was lying across the double bed. There was a syringe in his right arm, and there were empty vials around the room.
An internal review of access to non-controlled medicines at Tallaght Hospital concluded that it was not possible to put more restrictions on access to potassium chloride without impacting on patient safety.
Potassium chloride is used to prevent or to treat low blood levels of potassium (hyperkalaemia).
Potassium levels can be low as a result of a disease or from taking certain medicines, or after a prolonged illness with diarrhoea or vomiting. However, high doses can be lethal.
A spokesman for Tallaght Hospital said that in line with normal procedures, it conducted a review of its practices on access to non-controlled medicines.
"The hospital was found to be operating in compliance with existing regulations and it was found that any additional restriction on access could impact on patient safety," he said.
"While the review found that no change in existing practice was required, it was deemed that more regular audits of compliance with such procedures are conducted."
An autopsy found that the cause of Dr Osborne's death was hyperkalaemia, caused by the elevated levels of potassium in his system.
A spokesman for the hospital said it had extended its condolences to his family.
Dr Osborne had previously worked in Tallaght but had moved to Cork, where he started a new job. At the time of his death he was in Dublin for the weekend to see his girlfriend.