Milestone Pharmaceuticals secured FDA approval for Cardamyst (etripamil), a nasally administered treatment for paroxysmal supraventricular tachycardia (PSVT), after earlier regulatory setbacks. The approval clears an emergency-use, patient-facing option for a common symptomatic arrhythmia and follows two previous FDA rejections. Milestone plans to roll out the product to emergency departments and outpatient settings where rapid conversion of PSVT can reduce hospital admissions. PSVT is an episodic supraventricular tachycardia that can cause palpitations and syncope.