A woman with a codeine dependency posed as different people to trick doctors in polyclinics into delivering about $500 worth of cough medication to her, a court heard.

Eileen Siak, 33, who faced 21 charges of cheating, pleaded guilty to seven counts yesterday.

Deputy Public Prosecutor Vadivalagan Shanmuga said Siak was an accounts manager with a company when she received a customer database, which contained their personal particulars.

She saved it in her private e-mail folder instead of the company's e-mail account, and then used the customers' details to register for appointments at polyclinics.

Posing as them, she obtained her supply of cough medicine between April and August 2014, and the last time on March 4 last year, even though she did not have a cough.

Initially, she paid for her medication but she later began walking off without paying. She made off with $524 worth of medication in this manner.

A senior manager at National Healthcare Group Polyclinics, who manages nine polyclinics including Bukit Batok and Jurong which Siak frequented, made a police report on March 16 last year.

Siak's lawyer Josephus Tan said his client, a chemical engineering graduate and mother of one, has been suffering from codeine dependency since June 2013.

He said she has made full restitution and seen a psychiatrist and psychologist at the Institute of Mental Health (IMH) in a bid to manage her codeine dependency.

District Judge Shawn Ho postponed sentencing to Jan 13, pending a Mandatory Treatment Order (MTO) suitability report.

Under the MTO, offenders must attend compulsory treatment sessions with psychiatrists assigned by the Health Ministry and IMH.

The maximum punishment for cheating is three years' jail and a fine.