Unused medicines with potential for misuse or abuse in primary care

Abstract

Objective To assess the quantity and nature of prescribed medicines with potential for misuse returned to community pharmacies and general practice surgeries. Setting Community pharmacies (n = 51, 85% total) and general practice surgeries (n = 42, 69%) within the boundaries of Eastern Birmingham Primary Care Trust, UK. Method Medicines returned spontaneously by patients to participating sites were collected over eight weeks in May and June 2003. Data were recorded for each medicinal item including: patient sex, recommended International Non-proprietary Name (rINN), strength, form, legal classification, quantity and number of doses per day. Medicines were categorised into BNF therapeutic groups. A 'medicinal item' was defined as the total number of dose units of a medicine of the same form, strength and date of issue, returned for a given patient. Key findings Medicines were returned from 910 patients comprising 3765 medicinal items (2782 (73.9%) prescription-only medicines and 356 (9.5%) controlled drugs). Substantial amounts of unused, prescribed medicines with potential to cause harm or for misuse were returned, with anal-gesics, psychoactive and antiepileptic agents comprising 19.4% of returned medicinal items. Medi-cines of note that were returned included paracetamol-containing medicines (16 630 tablets), morphine (56 g), diamorphine (4.3 g), tramadol (2840 tablets and capsules), benzodiazepines (677 tablets) and tricyclic antidepressants (2831 tablets). Conclusions Substantial quantities of prescribed medicines with potential to cause harm or be mis-used are routinely present in the community. The management of these unused medicines, and in particular controlled drugs, is currently inadequate and further work is required to identify the leg-islative and patient-centred processes required to minimise the potential for these medicines to be misused or cause harm. Unused medicines in patients' homes have been recognised as a problem since the early 1970s when attempts were made to resolve this issue through Disposal of Unwanted Medi-cines and Pharmaceuticals (DUMP) campaigns. 1,2 More recently, a 1994 government sur-vey conducted by the Office of Population Censuses and Surveys reported that 52% of the households with unused medicines had allowed them to accumulate without disposal for over 12 months. 3 Additionally, a Portsmouth study in 1994 reported that just 10% of patients returned unwanted medicines to a pharmacy, with the remainder retaining medi-cines in their homes or disposing of them in grey and black water or household waste. 4 There is potential for these accumulated medicines to be misused in a variety of ways including self-poisoning, 5 recreational use, 6,7 and even malicious use in harming others. 8 Hawton and coworkers report that between 1997 and 1999, co-proxamol was responsible for 18% of drug-related suicides, with a further 22% caused by tricyclic antidepressants and 9% by paracetamol. 9 Additionally, in 2001, 616 deaths were caused by opioids, 109 by antiepileptic, sedative-hypnotic or antiparkinsonism drugs, and 43 by benzodiazepines. 10 The availability of such potentially lethal medicines in the home has been linked to suicide attempts involving self-poisoning. 5,11 The implication of paracetamol and aspirin in large numbers of self-poisoning cases led to changes to UK legislation during 1998 restricting availability of large quantities of paracetamol and aspirin over the counter (OTC), with a subsequent reduction in suicide deaths directly linked to these drugs. 12 Additionally, data