Rabinowicz, Adrian L

AbstractObjectiveCurrent diazepam nasal spray labeling requires waiting 4 h before administering a second dose. The objective of the current analyses was to examine safety and pharmacokinetic profiles of second doses of diazepam nasal spray given 0−4 h after the first dose.MethodsTwo datasets were analyzed. The first, a long‐term, repeat‐dose safety study of diazepam nasal spray, compared rates of treatment‐emergent adverse events (TEAEs), serious TEAEs, and treatment‐related TEAEs for patients receiving ≥1 second dose ≤4 h versus all second doses >4 h after the first. The second was a population pharmacokinetic analysis using data from three phase 1 studies to model drug exposure when a second dose of diazepam nasal spray was administered across multiple time points (1 min−4 h) following the first dose.ResultsIn the repeat‐dose safety study, a second dose of diazepam nasal spray was administered ≤24 h after the first to treat 485 seizure clusters in 79 patients. Rates of TEAEs were similar between patients receiving ≥1 second dose in ≤4 h (89.5%, n = 38) compared with >4–24 h only (80.5%, n = 41). The most common treatment‐related TEAEs were associated with nasal discomfort, which was mild or moderate and transient. There were no reports of respiratory or cardiac depression. The pharmacokinetic simulations of second doses predicted comparable elevations of plasma diazepam concentrations with administrations across a range of intervals after the first dose (1 min−4 h).SignificanceThese data indicate that the safety and pharmacokinetic profiles of a second dose of diazepam nasal spray administered within 4 h of the first dose are consistent with those associated with current labeling. This is potentially important for patients with seizure clusters who have a recurrent seizure within 4 h of first treatment and might benefit from immediate retreatment to reduce the risk of progression to status epilepticus.

Abstract Objective An exploratory analysis from a long‐term, phase 3, open‐label, repeat‐dose safety study of diazepam nasal spray for acute treatment of seizure clusters assessed the use of a second dose up to 24 hours after the initial dose and effectiveness in potentially reducing the number of seizures. Methods Seizures and doses were recorded in diaries. Results Of 175 patients enrolled, 163 received ≥1 dose of diazepam nasal spray and were included in the safety population; those patients received a total of 4390 doses for a total of 3853 seizure clusters. Less than half of these patients used a second dose a least once during the study (79 patients [48.5%]), with a total of 485 second doses for seizure clusters (12.6% of all seizure clusters). Among these 79 patients, 33 (41.8%) used only one second dose during the study (range: 1–82). The proportion of seizure clusters treated with a second dose over time was consistently low across 24 h: 0–4 h, 152 (3.9%); 4–6 h, 72 (1.9%); 6–8 h, 39 (1.0%); 8–12 h, 55 (1.4%); 12–16 h, 42 (1.1%); 16–20 h, 42 (1.1%); 20–24 h, 83 (2.2%). Rates of treatment‐emergent adverse events (TEAEs) and treatment‐related TEAEs occurring within 1 day of a second dose were low (15.2% and 5.1%, respectively). Significance Patients with epilepsy may experience seizure clusters lasting up to 24 hours, and little is known about the effectiveness of rescue therapies for that duration. The current labeling of the US Food and Drug Administration (FDA)–approved outpatient treatments for seizure clusters (rectal diazepam, intranasal midazolam, and diazepam nasal spray) allows for a second dose, if needed, for control. These findings support the safety profile of second doses, and the low use supports the effectiveness of diazepam nasal spray across 24 hours.