The Health Products Regulatory Authority (HPRA) has been asked by Mr Harris to provide an expert opinion on medicinal cannabis and any policy and legislative changes needed.
HPRA chief executive Lorraine Nolan told an Oireachtas Committee on Health that a group of medical experts would be assisting the authority.
Working in the area of controlled drugs since 2001, she said the views of patients also needed to be included.
“The timeline that we have been given on this by the minister is tight — we have been given until the end of January to work on this,” said Ms Nolan.
She stressed, however, that a review was necessary.
“It is really to protect patient safety the best way possible,” she said.
Vera Twomey whose daughter, Ava, suffers from an extremely rare form of epilepsy called Dravet syndrome, appealed to Mr Harris during the summer to take action on the issue.
Ms Twomey, of Aghabullogue, Co Cork, has been using cannabis oil to treat Ava, who suffers multiple seizures. She has already seen a major improvement.
She told the committee she just wanted to do everything she could for her dangerously ill six-year-old daughter. They had run out of treatment options and would rather be in a position where a doctor could prescribe the cannabis product for Ava.
Consultant neurologist at St James’s Hospital, Dublin, Colin Doherty said the use of marijuana to treat epilepsy offered “a tantalising new horizon” for severe disabling seizures. He said initial studies were encouraging but not definitive.
“Already it is possible to state with confidence that this drug will not work for everyone,” he said. “It will cause intolerable, but probably not dangerous, side effects in a few; but for those for who it will work it may be life-saving.”
He said only 10 countries in the world had legalised cannabis for medicinal use and only one country, Australia, had a proper national framework for prescribing it for children with epilepsy.
He said an important issue that needed to be addressed was the drug’s cost. There was a process that had to be gone through to get a drug listed on a long-term illness scheme.
Dr Doherty said about 15,000 of the 40,000 people in Ireland with epilepsy were not in full control of the condition. Several thousand have very severe epilepsy.
“Many have reached the end of the line, just like Vera’s daughter,” he said. “They have tried everything, maybe 10 to 12 different types of drugs.”
However, he said there must be “clear scientific evidence” that cannabis-based drugs worked.