Abstracts

Rationale: In 2016 we presented a clinical audit of the generic substitution of levetiracetam in our hospital pharmacy [1]. We have now extended the project to include additional antiepileptic drugs. Our hospital pharmacy recently introduced generic substitution of topiramate and lamotrigine.  Potential cost savings of up to 37-49 USD per person per month (assuming a conservative 100 mg twice a day dose) can be expected with the switches, equivalent to 441-588 USD per annum. This audit aimed to evaluate the generic substitution outcomes. Methods: Patients collecting prescriptions of branded and generic topiramate or lamotrigine for epilepsy from our hospital pharmacy from mid-November 2016 to mid-November 2017 were identified. Retrospective data was collected via telephone using a data capture form, including information on the recalled number of seizures, adverse events, positive effects and opinions about generic medication in general. Results: 45/89 (51%) responded to a phone call: when asked about the generic substitution 40/45 (89%) had no concerns; 4/45 (9%) thought it was a good idea; 1/45 (2%) was worried about it. 14/29 (48%) taking topiramate responded to a phone call, 5/14 were under 18 years of age. 31/60 (52%) taking lamotrigine responded to a phone call, 2/31 were under 18.Of the 14 patients taking topiramate, 10 remembered taking generic only and 4 had switched from branded to generic in the previous 2 months. 7/14 (50%) reported a reduction in seizures, 4/14 (29%) no change, and 3/14 (21%) an increase over 2 months. Of the 4 who recalled switching, 2 found a decrease, 1 an increase, and 1 no change. 11/14 (79%) reported adverse effects including weight loss, drowsiness and mood changes. Positive effects were reported in 4/14 (27%), including better memory and fewer headaches in the previous 2 months.Of the 31 patients taking lamotrigine, 19 remembered taking generic only and 12 had switched from branded to generic in the previous 2 months. 20/31 (65%) reported a decrease in seizures, 7/31 (23%) no change, and 4/31 (10%) an increase over 2 months. Of the 14 who recalled switching, 7 found a decrease, 4 no change and 3 an increase. 8/31 (26%) reported adverse events including headaches, tremors and tiredness. Positive effects were reported in 1/31 (3%) including feeling more relaxed, in the previous 2 months.Overall, no serious adverse events were reported and switching was well accepted. Comments regarding switching included “both brands do the same job,” “same medication, different name”, and “some brands work better.” Conclusions: The number of patients recalling switching was too small to draw firm conclusions. However, the data so far is encouraging, the switching was feasible, and did not cause significant problems in these 45 patients (0/45: 95 CI 0 to 8%). We encourage other departments to do likewise, saving ~400-550 USD per patient per year.Reference1. Moran M, Little E, Simmonds J, Lane J, Whitehouse W. Generic substitution of levetiracetam in a hospital pharmacy. American Epilepsy Society, December 2016, Houston. Funding: No funding recieved.