Investigating unused medications in New Zealand

Abstract

Objective: 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.

Setting: 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.

Methods: 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.

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

Results: 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.

Conclusions: 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.