The FDA has approved Cardamyst (Milestone), a nasal spray formulation of the nondihydropyridine calcium channel blocker etripamil, for conversion of acute symptomatic episodes of paroxysmal supraventricular tachycardia (PSVT) to sinus rhythm in adults. Cardamyst is the first product containing etripamil to be approved in the US. It is being marketed as the only FDA-approved, self-administered, rapid-acting treatment option for acute episodes of PSVT.