Ms Stringer said the theft was identified during routine monitoring and an investigation immediately undertaken.
"We have clear guidelines, policies and procedures around the procurement, use and storage of prescription drugs and potentially harmful substances and all clinical staff are briefed on these.
"A full review will be under taken following this incident. However, it has demonstrated that the monitoring processes we have in place are effective in ensuring patient safety."
Detective Senior Sergeant Barry Bysouth said the charges related to the theft of a large amount of prescription anaesthetic from within a secure area of the hospital.
He said the investigation appeared to indicate that one of the people charged was stealing drugs for consumption by the second person.
"It is the police's role to ensure that persons who offend in this way are placed before the courts as soon as possible to prevent further harm occurring to any person.
"In this case, one of those charged was apparently using the stolen drug. I firmly believe that the intervention of the DHB and police working together has prevented the loss of life which was a real possibility if this offending had been allowed to continue," Mr Bysouth said.
Police were working closely with the Wairarapa DHB in an attempt to establish the circumstances around the theft and to identify the steps required to prevent similar offending.