The group hopes to leave from Dublin next week to demand that the Bahraini authorities free the captives.
Doctors and nurses -- three of whom were trained in the Royal College of Surgeons in Ireland (RCSI) -- were arrested during pro-democracy demonstrations in the middle east country.
They could face execution if convicted.
Fianna Fail Senator Averil Power said she has been following the unrest in the area and was stunned at the treatment of the medics.
"It's quite extraordinary for doctors to be arrested in any country," Ms Power told the Herald. "These doctors were arrested for doing their jobs."
"The families haven't been able to talk to those in detention. It was two months after they were arrested before they had access to legal counsel."
Senator Power has signed up to leave on July 12, along with MEP Marian Harkin, former minister for foreign affairs David Andrews and representatives from the Irish Nurses and Midwives Organisation (INMO). She was persuaded after being shown the extent of the situation by orthopaedic surgeon Professor Damien McCormack, who is one of several doctors to have criticised the RCSI for failing to condemn the detentions.
"As a member of the Oireachtas it might provide the group with some form of safety -- the group can say that a member of the Irish parliament is travelling with them," she explained.
The RCSI's silence has been criticised by many doctors, some of whom have resigned in protest from the organisation.
"I don't understand their silence," Ms Power said of the RCSI. "Doctors have a moral responsibility to act."
However, it's understood the RCSI may have been concerned that any criticism could threaten the safety of its staff and students in Bahrain.
A total of 47 doctors and nurses remain in custody on charges of acting against the state. Prof McCormack, who works at Temple Street children's hospital, said he worked alongside several of the doctors from Bahrain, who now could face possible execution.
"They were excellent ambassadors for Bahrain when they worked in Dublin," he said.