Cardamyst (Etripamil) Nasal Spray Now Commercially Available for Adults with PSVT

Milestone Therapeutics’ etripamil nasal spray for the conversion of acute symptomatic episodes of paroxysmal supraventricular tachycardia (PSVT) to sinus rhythm in adults has officially been released for commercial sale in the US under the brand name Cardamyst.1

Initially approved by the US Food and Drug Administration (FDA) on December 12, 2025, Cardamyst is a novel calcium channel blocker nasal spray designed to be self-administered by patients in the event of a PSVT attack, independent of medical oversight. The treatment offers patients a substantial degree of control over what has historically been a difficult-to-predict condition, as well as circumventing the need for hospitalizations and emergency room visits.2

“Treatments for PSVT have been quite limited up to this point,” David Bharucha, MD, PhD, chief medical officer of Milestone Pharmaceuticals, told HCPLive in an exclusive interview. “They’ve been particularly limited for treatments that can be given acutely to patients when they first experience an attack of PSVT. The condition is frequently impinging on patients’ lives because they can’t get through their normal everyday activities, and so acute treatment becomes more critically important.”

Cardamyst’s launch was accompanied by the release of a patient assistance platform, which aims to optimize affordability as Milestone continues to negotiate regarding formulary placement and coverage with insurers. The program includes reimbursement support and copay assistance for the majority of patients with commercial insurance covering Cardamyst. Copays are currently capped at $25.1

Cardamyst’s FDA approval was based on several trials within the larger NODE program, including NODE-1, NODE-301 parts 1 and 2, NODE-302, and NODE-303. A collective analysis of these trials was presented at the American Heart Association’s 2025 Scientific Sessions, exhibiting the overall safety, efficacy, and test-dose tolerability of Cardamyst in patients with PSVT.2,3

Across all of the included studies, the Kaplan-Meier estimate of etripamil exposed patients converting to sinus rhythm within 30 minutes (n = 622) was 59.6% (range, 53.6-64.3%), with a recorded mean time to conversion of 18.5 minutes (95% CI, 15.7-21). Additionally, the proportion of patients assigned to placebo across these trials converting to sinus rhythm by 30 minutes ranged from 26.7-34.7%.3

The combined analysis also showed the occurrence of primarily mild, transient treatment-emergent adverse events, which primarily took the form of nasal discomfort, nasal congestion, rhinorrhea, throat irritation, and epistaxis. A total of 1107 patients took ≥1 etripamil test dose while in sinus rhythm, and no significant changes in average baseline heart rate or blood pressure was observed within 45 minutes of administration. Test dose failure occurred in only 16 patients (1.4%).3

“So, what all this boils down to is that it’s safe and well-tolerated; patients in trials who could take doses for consecutive separated episodes of PSVT attacks returned to this treatment,” Bharucha said. “And the efficacy data demonstrate that it’s fast, effective, and lasts for well beyond 30 minutes. We keyed in on 30 minutes because that was our primary endpoint, and that’s often the time in which patients have to make a decision. In reality, the effects were long-lasting up until 5 hours, which is when we stopped measuring.”

Editor’s Note: Bharucha reports that he is an employee of Milestone Pharmaceuticals.

References

1. Milestone Pharmaceuticals. Milestone Pharmaceuticals Announces US Availability of CARDAMYST (etripamil) Nasal Spray, the First and Only FDA-Approved Self-Administered Treatment for Adults with Paroxysmal Supraventricular Tachycardia (PSVT). January 26, 2026. Accessed January 29, 2026. https://investors.milestonepharma.com/news-releases/news-release-details/milestone-pharmaceuticals-announces-us-availability-cardamysttm

2. Livingston R. FDA Approves Etripamil (Cardamyst) Nasal Spray for PSVT. HCPLive. December 13, 2025. Accessed January 29, 2026. https://www.hcplive.com/view/fda-approves-etripamil-cardamyst-nasal-spray-for-psvt

3. Ip J, Noseworthy P, Piccini J, et al. Combined Efficacy, Safety, and Test Dose Tolerability of Etripamil for Acute Paroxysmal Supraventricular Tachycardia (PSVT) Across Multiple Clinical Trials. AHA/ASA Journals. November 3, 2025. Accessed December 9, 2025. https://www.ahajournals.org/doi/10.1161/circ.152.suppl_3.4366812