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

Abstract

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. 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. 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. 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. 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.