Prolonged in HF, liver disease, shock, severe renal disease Metab: H Excr: U Cardiac: Bradycardia, hemodynamic collapse, AVB, sinus arrest Other: Delirium, psychosis, seizure, nausea, tinnitus, dyspnea, bronchospasm (Continued) CLINICAL STATEMENTS AND GUIDELINES Metoprolol (II) IV: 5 mg q 5 min up to PO: 25 100 mg Extended release qd or q 12 h VT, PVC Beta 1 receptor Sinus rate slowed AV nodal refractoriness increased : 3 4 h Metab: H Excr: U Cardiac: Bradycardia, hypotension, AVB Other: Dizziness, fatigue, diarrhea, depression, dyspnea Mexiletine (IB) PO: 150 300 mg q 8 h or q 12 h T, VF, PVC, has a role in patients INa No marked effect on most intervals; QTc can slightly shorten : 10 14 h Metab: H Excr: U Cardiac: HF, AVB Other: Lightheaded, tremor, ataxia, paresthesias, nausea, blood dyscrasias Nadolol (II) PO: 40 320 mg daily VT, PVC, LQTS, CPVT Beta 1 and 2 receptors Sinus rate slowed AV nodal refractoriness increased : 20 24 h Metab: none Excr: U Cardiac: Bradycardia, hypotension, HF, AVB Other: Edema, dizziness, cold extremities, bronchospasm Procainamide (IA) IV: loading dose 10 17 mg/kg at 20 50 mg/ min Maintenance dose: 1 4 mg/min PO (SR preparation): 500 1250 mg q 6 h VT INa , IKr QRS prolonged QTc prolonged; increased DFT Metab: H : 2 5 h; NAPA 6 8 h prolonged in renal dysfunction. Anephric: proc 11 h and NAPA Excr: U Cardiac: TdP; AVB, hypotension and exacerbation of HFrEF Other: Lupus symptoms, diarrhea, nausea, blood dyscrasias Propafenone (IC) PO: Immediate release 150 300 mg q 8 h Extended release 225 425 mg q 12 h VT, PVC (in the absence of structural heart disease) INa , IKr , IKur , Beta receptor, Alpha receptor PR prolonged QRS prolonged; increased DFT : 2 10 h or 10 32 h : extensive h; poor metabolizers 10 32 h. Metab: H Excr: U Cardiac: HF, AVB, drug-induced Brugada syndrome Other: Dizziness, fatigue, nausea, diarrhea, xerostomia, tremor, blurred vision Propranolol (II) IV: 1 3 mg q 5 min to a total of 5 mg PO: Immediate release 10 40 mg q 6 h; Extended release 60 160 mg q 12 h VT, PVC, LQTS Beta 1 and 2 receptors, INa Sinus rate slowed AV nodal refractoriness increased : Immediate release Extended release 8 10 h Metab: H Excr: U Cardiac: Bradycardia, hypotension, HF, AVB Other: Sleep disorder, dizziness, nightmares, hyperglycemia, diarrhea, bronchospasm Quinidine (IA) PO: sulfate salt 200 600 mg q 6 h to q 12 h gluconate salt 324 648 mg q 8 h to q 12 h IV: loading dose: 800 mg in 50 mL infused at T, VF, (including short QT syndrome, Brugada) INa , Ito , IKr , M, Alpha receptor QRS prolonged QTc prolonged; increased DFT : 6 8 h longer in HF, liver cirrhosis, and with older age Metab: H Excr: U Cardiac: Syncope, TdP, AVB Other: Dizziness, diarrhea, nausea, esophagitis, emesis, tinnitus, blurred vision, rash, weakness, tremor; blood dyscrasias Ranolazine (not classified) PO: 500 1000 mg q VT INa , IKr Sinus rate slowed Tc prolonged : 7 h Metab: H Excr: U 75%, F 25% Cardiac: Bradycardia, hypotension Other: Headache, dizziness, syncope, nausea, dyspnea Sotalol (III) IV: 75 mg q 12 h PO: 80 120 mg q 12 h, may increase dose every 3 d; max 320 mg/d VT, VF, PVC IKr , Beta 1 and 2 receptor Sinus rate slowed QTc prolonged AV nodal refractoriness increased; decreased DFT : 12 h Metab: none Excr: U Cardiac: Bradycardia, hypotension, HF, syncope, TdP Other: Fatigue, dizziness, weakness, dyspnea, bronchitis, depression, nausea, diarrhea Table 7. 