Exploration of inherited propensity for codeine misuse and dependence

The opioid codeine has been used for medical purposes since it was isolated from opium in the nineteenth century. It has multiple applications and is frequently used as an analgesic, anti-diarrhoeal, and anti-tussive agent. It is listed as a World Health Organisation essential medicine.

As an opioid, codeine use elicits concerns relating to misuse and the development of dependence. Because of these concerns, controls are commonly put in place to limit access to it. In New Zealand, codeine was rescheduled as a prescription medicine in November 2020, ceasing over-the-counter sales.

Our study aims to find out if some people are more susceptible to the effects of codeine and whether some people are more likely to misuse or become dependent on it. This may indicate whether the restrictions introduced to restrict the availability of codeine via pharmacy sales were based on a genuine clinical risk or one limited to a small proportion of the general population.

Taking part will involve a brief telephone conversation with a researcher to confirm you meet our study criteria.

People who meet the study inclusion criteria will be invited to participate in a short Zoom video (or telephone) interview. The interview will discuss their use of the drug codeine and explore aspects including codeine use disorder, how much codeine they take, how long they have taken it and where they obtain it. Each interview will take a maximum of 30 minutes.

Eligible participants will also be asked to provide a saliva sample for genotype analysis. A test kit will be posted to them and after providing a sample the sample will be sent in a pre-paid courier bag back to the University laboratory for analysis.

You will receive $50 gift voucher as koha for your time.

Eligibility will be confirmed in a brief telephone screening with people who express an interest in participation. Anyone over the age of 18 is eligible for the screening process.