For example, amiodarone (Cordarone®) administration is decreased over 2–3 days: a high dose (900 mg/ day) without co-administration of alpha-2 agonists is reduced to a low dose (300 mg day-1) with co-administration of an alpha-2 agonist or preferably to complete cessation, as a function of HR or arrhythmias. The gene discussed is PSMA2; the disease is cardiac arrhythmia.