Other Fisons offices to close include a site in Manchester employing 95 staff, and what remains of the Loughborough operation following the sale of Fisons' research arm to Astra of Sweden.
A company spokesman said some staff would be offered the chance to relocate to London but there would inevitably be compulsory redundancies.
News of the move leaked out earlier this week after Fisons' shares, which hit a low of 105p in January, put on 15p in two days to reach a high for the year of 180p. Yesterday they closed 1p higher at 181p.
Three weeks ago Stuart Wallis, chief executive for the past six months, announced a £220m provision to cover restructuring of the group. He said at the time that he was putting in place a big cost-cutting programme.
Since the beginning of the year, Fisons has also sold its scientific instruments division for £202m and its research operations for the same amount.
Still to come is the proposed disposal of the company's laboratory supplies arm for an estimated £250m to £300m. Negotiations are understood to be at an advanced stage, with details expected within weeks.
The decision to centralise Fisons' head office is understood to involve the removal of duplicated administrative functions, including several different public relations departments. The new head office will probably have about 80 staff.
Mr Wallis said: "Although it is regrettable that some jobs will be lost, the board has concluded that a smaller, single head office and a flatter management structure is more appropriate for the new, refocused Fisons."
The changes at the company are part of the creation of a niche respiratory drug marketing business, which some analysts doubt has an independent future. Much of the strength of the shares this year stems from speculation that another drug company, possibly Zeneca, will bid for the rump.Reuse content