The Deputy Health and Disability Commissioner has found a man wrongly took a chemotherapy drug for three weeks because a pharmacy dispensed the wrong medication.
The 79-year old man was supposed to be taking an immuno-suppressant, following a kidney transplant.
He took the chemotherapy drug for about three weeks before asking the pharmacist why his tablets had changed.
The pharmacist checked the records and found a technician had filled the prescription, but that he had signed it off.
He then failed to report the error, which was only uncovered when the pharmacy owner noticed stocks of the chemotherapy drug had run out.
Deputy Health and Disability Commissioner Theo Baker said she was more concerned about how the pharmacist managed his mistake than the actual error.
Ms Baker said the patient eventually questioned why the pills appeared different from his usual prescription and the pharmacist told him to stop taking them.
"He knew then that probably an error had been made, he then checked to see who had made the error and and realised he himself had been involved in the dispensing, but he did nothing further, he didn't complete an incident form, he didn't alert the owner of the pharmacy to it."
She said the pharmacist was also remiss for not offering any counselling to the patient.
The pharmacist has been ordered to apologise to the man in writing, and further action could follow.