Pharmacokinetics/pharmacodynamics of epinephrine after single and repeat administration of neffy, EpiPen, and manual intramuscular injection.

BACKGROUND: Epinephrine is the first-line treatment for severe allergic reactions, and rapid treatment is associated with lower rates of hospitalization and death. Current treatment options (epinephrine auto-injectors and manual intramuscular injection) are considered cumbersome, and most patients/caregivers fail to use them, even during severe reactions. An intranasal epinephrine delivery device, neffy, has been designed to provide an additional option for patients/caregivers. OBJECTIVE: We sought to assess the comparative pharmacokinetics and pharmacodynamics of neffy 2.0 mg, EpiPen 0.3 mg, and manual intramuscular injection 0.3 mg. METHODS: This was a phase 1, randomized, 6-treatment, 6-period, 2-part crossover study in 59 healthy subjects. Pharmacokinetic and pharmacodynamic parameters following single and repeat doses of epinephrine were assessed before dosing and at various postdose intervals. RESULTS: The pharmacokinetic profile of neffy was bracketed by approved injection products, with a mean peak plasma level of 481 pg/mL, which fell between EpiPen (753 pg/mL) and epinephrine manual intramuscular injection (339 pg/mL). When dosed both once and twice, neffy resulted in more pronounced increases in pharmacodynamic parameters relative to EpiPen or manual injection. CONCLUSIONS: neffy's pharmacokinetic profile was bracketed by approved injection products, with pharmacodynamic responses that were comparable to or better than approved injection products. neffy is expected to be a safe and effective option, particularly for patients/caregivers who are reluctant to carry and use injection devices.