Intranasal Epinephrine Powder Safety After Double Dose, With Michael Blaiss, MD

Double-dose FMXIN002 (NS002), an investigational intranasal epinephrine powder, raised systolic blood pressure without cardiovascular or serious adverse events in adults with allergic rhinitis, according to data presented at the 2026 American College of Allergy, Asthma & Immunology (ACAAI) Annual Scientific Meeting in Pheonix.¹

In an interview with HCPLive, investigator Michael S. Blaiss, clinical professor of pediatrics at the Medical College of Georgia at Augusta University, detailed the blood pressure, heart rate, and adverse event findings from the phase 2 double-dose study and explained how he counsels patients on a second dose. HCPLive previously reported the study’s pharmacokinetic results, in which FMXIN002 reached plasma epinephrine of 100 pg/mL faster than a 0.3-mg autoinjector.²

“Our biggest problem with patients right now is carrying an auto injector with them and having it when, in fact, they may have an anaphylactic reaction,” Blaiss said. He added a small, needle-free device could address this gap for patients who need to carry epinephrine at all times.

FMXIN002 Blood Pressure and Heart Rate After Double Dosing

The study enrolled 50 adults with allergic rhinitis. Participants received 2 doses of FMXIN002 4 mg 10 minutes apart, under normal conditions or after a nasal allergen challenge (NAC), with a double-dose 0.3-mg autoinjector as the comparator.¹ Pharmacodynamic measures included systolic blood pressure (SBP), diastolic blood pressure (DBP), and heart rate.¹

Across both normal and NAC conditions, mean SBP rose by approximately 22 mm Hg at 15 to 20 minutes with FMXIN002, compared with approximately 6 mm Hg with the autoinjector, according to Blaiss. DBP stayed near baseline under both conditions. Heart rate was broadly equivalent between groups, with some increase relative to the autoinjector.

Blaiss said no participant had a cardiovascular adverse event. Pharmacodynamic responses followed expected epinephrine effects and remained within normal physiological limits.¹

FMXIN002 Adverse Events and Second-Dose Counseling

No serious adverse events (AEs) were reported with either treatment.¹ According to Blaiss, most AEs with FMXIN002 were local and self-resolving, and 95% were mild, although AEs were more frequent after double dosing. The main difference from the autoinjector was the type of AE: events with FMXIN002 were mostly local, and events with the autoinjector were mostly systemic.

The most common local AEs with FMXIN002 were runny nose, administration site discomfort, nasal itching, and nasal congestion. Systemic AEs, including headache, nausea, shakiness, stomach discomfort, lightheadedness, and vomiting, occurred only after double dosing under NAC conditions, Blaiss said.

Blaiss advises patients to take a second dose if they do not feel significant improvement within 5 to 10 minutes of the first or if their symptoms worsen.

“I’m very liberal as far as patients getting a second dose,” Blaiss said. “If there’s any question they’re not having a significant improvement as far as decrease of symptoms of anaphylaxis with the first dose, they should definitely administer the second dose in that 10-minute time frame.”

References

1. Blaiss M, Lapidot T, Megiddo D, Abrutzky C, Temtsin Krayz G. Enhanced absorption of intranasal powder epinephrine (FMXIN002) after double dose in adults with allergic rhinitis. Presented at: American College of Allergy, Asthma & Immunology 2026 Annual Scientific Meeting; November 12-16, 2026; Phoenix, AZ.

2. FMXIN002 double dose delivers faster epinephrine exposure than autoinjector. https://www.hcplive.com/view/fmxin002-double-dose-faster-epinephrine-exposure-autoinjector. HCPLive. Published November 12, 2026. Accessed November 13, 2026.