Investigating unused medications in New Zealand

The objectives of this study were to determine the reasons for returning medications unused and the types of unused medications returned based on therapeutic class.

This study was conducted in a region of New Zealand covered by the Hutt Valley District Health Board. This region has approximately 51,000 households.

A 'Disposal of Unwanted Medication Properly (DUMP)' campaign was conducted for a four week period in November 2007 in the Hutt Valley DHB region. A collection bag was delivered to every household for the collection and disposal of any unused medications. Participants were instructed to return the bags to a community pharmacy. Those returning medications were also asked to complete a questionnaire to determine why the medications were not used. A sample of the returned medications was identified and quantified and every completed questionnaire was analysed.

The main outcome measures included: types and quantities of medications returned, calculated costs of these medications and reasons for returns.

Over the four week period, 1,605 bags were returned for disposal. A total of 329 bags (20%) containing a total of 1,253 items were fully analysed. Only 653 questionnaires were completed (41%) all of which were analysed. The most commonly reported reason for not using the medication was that it had passed the expiry date (26%), the second was treatment change (24%), followed by condition resolved (15%). 'Alimentary tract & metabolism' and 'respiratory systems & allergies' accounted for 21 and 20% of cost respectively.

This study found that main reasons identified for patients having unwanted medications were 'treatment changes' and 'expired'. Additionally respiratory medications contributed 20% of the costs associated with unused medications.