Abstracts

Rationale: Patients with intractable epilepsy by definition eventually need treatment trials with multiple different anti-seizure medications (ASM). They are more likely to be on ASMs approved since 2008, will continue to have breakthrough seizures and have high rates of morbidity and mortality. The commonest reason for breakthrough seizures is missing medication doses. Prompt resumption of the patients ASMs is the best way to prevent further seizures and reduce the risk of further complications such as status epilepticus, asphyxia and death. This high risk population frequently present to local emergency rooms when breakthrough seizures occur or for other medical or surgical reasons in which they may occur.

We hypothesize that in-patent pharmacies are not sufficiently stocked with the ASMs that this population depends on, placing them at special additional and under-appreciated risk. With the approval of newer and potentially more efficacious ASMs in the future this situation may deteriorate.

There is little in-patient pharmacy formulary transparency to aid treating physicians in counseling patients and families so as to pre-empt and off-set these risks.

Methods: We surveyed all acute care general hospitals in Maryland with > 100 beds. We excluded VA and military hospitals and the National Institutes of Health. In-patient pharmacists were contacted directly by telephone or email between August 2020 and May 2021 and asked what ASMs they had on the shelf for immediate dispensation. We excluded ethosuximide, tiagabine, vigabatrin, cannabidiol, and fenfluramine with usage in mostly pediatric or very small populations.

Results: 100% of the candidate hospitals in Maryland responded n = 28. Pharmacies even within the same medical system usually had individualized formularies. Phenytoin, Phenobarbital, primidone, valproic acid, divalproex, carbamazepine, topiramate, gabapentin, levetiracetam (oral/IV), lacosamide (oral) available in 28 (100%). Lamotrigine and pregabalin n = 27 (96.4%), lacosamide IV n= 26 (92%) oxcarbazepine n = 25 (89%), zonisamide n=20 (71%), clobazam n = 9 (32.14%), brivaracetam oral n = 6, (21.4%), IV n=5 (17.6%), perampanel n = 4 (14.3%), eslicarbazepine n = 3 (10.7%), cenobamate n =0 (0%).

Conclusions: Most in-patient pharmacies in Maryland carry older first and second generation ASMs. Newer ASMs especially clobazam, brivaracetam, perampanel, and cenobamate which cater to more intractable patients and whose use is in the ascendancy are often not available in emergency rooms when needed most. Some of these ASMs are not easily interchangeable especially in brittle patients. Formulary information is not readily available to physicians and patients' families. Improvements in formulary transparency, and novel strategies such as potentially maintaining a 72 hour supply of most approved ASMs should be explored. Physician awareness and counseling when newer ASMs are prescribed is paramount.

Funding: Please list any funding that was received in support of this abstract.: None.