Procainamide

 Procainamide:

(Lexicomp, 21^st ed. 2014-2015)

 

SVT:

(May use for stable, monomorphic VT and pre-excited A fib).

Newborn:

IV-Loading dose 5-10 mg over 60 min.

Infusion: 20 – 80 mcg/kg/min.

(Lower dose for preterm and renal impairment).

Infants/Children/Adults:

Loading dose 10-2 mg/kg over 30-60 min.

Infusion: 20-80 mcg/kg/min.

 

Monitoring:

EKG (PR interval, QTc prolongations), BP, CBC/diff.

Drug level: 6-12 hrs. after starting infusion.

Therapeutic range:

Procainamide level 4-10 mcg/ml. (> 10-12 mcg/ml is toxic)

Proc + NAPA level = 10-30 mcg/ml.

Side effects:

- PR, QTc prolongation, Paradoxical increase in ventricular rate in Afib.

- Agranulocytosis

- ANA positive

- Others.

Flecainide Dose (Lexicomp, accessed on 3/4/2026)

Newborn:

Initial: 2 mg/kg/day in 2 divided doses.

Usual effective dose: 3.35 ± 1.3 mg/kg/day.

 

Children:

Initial: 1-3 mg/kg/day (or) 50 – 100 mg/m2/day in 3 divided doses.

Max: 8 mg/kg/day (or) 200 mg/m2/day.

Usual effective dose: 4 mg/kg/day (or) 140 mg/m2/day.

 

Adults:

Initial: 50 mg q12 or 100 mg qd.

Increase dose Q4 days, Max. 300 mg/day for SVT & 400 mg/day for VT.

Pill-in-pocket for A fib: 200 mg (< 70 kg) & 300 mg (> 70 kg). Patient should be on AV nodal blocking agent (Beta-blocker or Calcium-channel blocker) while on this plan. Inpatient trial should be done prior to discharge to check its efficacy.

 

Monitor: 

EKG, Serum trough level. LFT, CBC/diff.

Serum trough level – Check 3 days after starting or changing medication.

Therapeutic level: 0.2 – 1.0 mcg/ml.

In children, response is noted at 0.2 – 0.5 mcg/ml range.

Side effects:

- PR prolongation, QRS widening, paradoxical increase in ventricular rate in A fib.

- Leukopenia, thrombocytopenia

- LFT

- Paraesthesia, blurred vision

- Urticaria

Kawasaki Disease Management (2024 Guidelines)

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