Overview
11 DESCRIPTION Etripamil, the active ingredient of CARDAMYST is a calcium channel blocker. The chemical name of etripamil is benzoic acid, 3-[2-[[(4S)-4-cyano-4-(3,4-dimethoxyphenyl)-5-methylhexyl]methylamino]ethyl]-, methyl ester. Its molecular weight is 452.59 and its molecular formula is C 27 H 36 N 2 O 4 . The structural formula is: Etripamil is a colorless to slightly yellow oil.
Mechanism of Action
12 CLINICAL PHARMACOLOGY 12.1 Mechanism of Action Etripamil is an L-type calcium influx inhibitor (slow channel blocker or calcium ion antagonist). Etripamil exerts its pharmacologic effect by modulating the influx of ionic calcium across the cell membrane of the AV nodal cells as well as arterial smooth muscles and contractile myocardial cells. By interrupting reentry at the AV node, etripamil can restore sinus rhythm in patients with PSVT. 12.2 Pharmacodynamics Cardiac Electrophysiology Etripamil prolonged the baseline PR interval by 8% to 10% approximately 5 minutes following an intranasal dose of 70 mg. This PR interval prolongation begins to decline shortly after the etripamil maximum concentration (C max ) and falls below the 8 to 10% threshold between 25 and 50 minutes.
Indications
- 1 INDICATIONS AND USAGE CARDAMYST is indicated for the conversion of acute symptomatic episodes of paroxysmal supraventricular tachycardia (PSVT) to sinus rhythm in adults. CARDAMYST is a calcium channel blocker indicated for the conversion of acute symptomatic episodes of paroxysmal supraventricular tachycardia (PSVT) to sinus rhythm in adults ( 1 ).
Common Doses
- 70 mg
- 140 mg
Dosage
2 DOSAGE AND ADMINISTRATION For intranasal use only ( 2.1 ). Initial dosage: A dose of 70 mg is administered as two nasal sprays, one spray into each nostril. Each nasal spray device delivers two sprays. The two sprays together contain a total of 70 mg etripamil ( 2.1 ). Repeat dosage (if needed): Should symptoms persist for 10 minutes after administration of CARDAMYST, take a second dose of 70 mg administered as two nasal sprays, one spray into each nostril. Do not exceed 140 mg in a 24-hour period ( 2.1 ). 2.1 Recommended Dosage Administer as soon as possible after PSVT symptom onset.
Contraindications
- 4 CONTRAINDICATIONS CARDAMYST is contraindicated in patients with: Hypersensitivity to CARDAMYST or any of its components. Heart failure – New York Heart Association (NYHA) Class II to IV. Wolff-Parkinson-White (WPW), Lown-Ganong-Levine (LGL) syndromes, or manifest pre-excitation (delta wave) on a 12-lead electrocardiogram (ECG). Sick sinus syndrome without a permanent pacemaker. Second degree atrioventricular (AV) Mobitz 2 block or higher degree of AV block. Hypersensitivity to CARDAMYST or any of its components ( 4 ). Heart failure - New York Heart Association (NYHA) Class II to IV ( 4 ).
Side Effects
- 6 ADVERSE REACTIONS The following clinically significant adverse reactions are described elsewhere in the labeling: Risk of syncope [see Warnings and Precautions ( 5.1 )] Most common adverse reactions (incidence > 5%) are nasal discomfort, nasal congestion, rhinorrhea, throat irritation, and epistaxis ( 6.1 ). To report SUSPECTED ADVERSE REACTIONS, contact Milestone Pharmaceuticals USA, INC. at toll-free phone 1-877-207-4764 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.
Interactions
- No major interactions listed on the FDA label. Always consult a healthcare professional.